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920 Cards in this Set
- Front
- Back
what three cell types are found in taste buds
|
support cells
basal cells neuroepithelial cells |
|
what structures are found on the posterior 1/3 of the tongue
|
glands and lingual tonsils
|
|
what do the serous cells of the salivary gland secrete
|
amylase
lysozyme lactoferrin |
|
What is the major antibody secreted by the salivary gland and where does it originate?
|
IgA: secreted by plasma cells in the underlying CT, absorbed by serous cells, coated with glycoprotein, secreted into saliva
|
|
What is the name change that the ducts of salivary glands undergo from inside out?
|
intercalated
striated (intralobular) excretory (interlobular) go from cuboidal to columnar |
|
What are serous demilunes and what are they thought to secrete?
|
Serous cell caps surrounding the mucous cells - secrete lysozyme
|
|
What pathology is connected with the parotid gland?
|
primary target of rabies and mumps virus; mumps infection can spread causing orchitis and meningitis, also most frequent site for slow growing benign adenomas
|
|
what are the 4 main layers of the gut tube (inside to out)
|
mucosa
submucosa muscularis externa serosa/adventitia |
|
Where in the gut tube is the MALT found and what is it?
|
lamina propria, accumulation of lymphoid tissue
|
|
What is the function of the muscularis mucosa?
|
promotes contact of the mucosa with food; aggitations expel secretions from gland ducts
|
|
In which layer of the gut tube are the Meissner's nerve plexi found
|
submucosa
|
|
Which layer of the gut tube is responsible for peristalsis and what important structures does it contain
|
muscularis externa - contains Aurbach's nerve plexi
|
|
What is the mucosal change between the esophagus and the stomach?
|
Stratified squamous to simple columnar
|
|
Which part of the stomach has the most elaborate glands
|
fundus and body
|
|
What is unique about the muscularis externa of the stomach?
|
It has three layers: oblique, circular, longitudinal (from inner to outer) - the rest of the gut tube only has 2 layers
|
|
What are the three parts of the gastric glands from outer to inner?
|
isthmus
base neck (main part) |
|
What is the purpose of the mucous neck cells and where are they found?
|
secrete mucous that adds to the protective gel layer produced by the epithelial cells - found in the upper gland
|
|
What do parietal cells secrete and where are they found
|
HCl and intrinsic factor
found all over the gland but mainly in the upper 2/3 |
|
How do parietal cells stain and why
|
very eosinophilic and contain many mito
|
|
How does the parietal cell obtain its HCl for secretion?
|
Hydrogen ion from carbonic anhydrase reaction; chloride ion through active transport
|
|
What does intrinsic factor do and why is it important?
|
It binds Vitamin B12 so that it can be absorbed in the small intestine - Vitamin B12 is used in the formation of RBCs
|
|
What will be caused by an autoimmune disease that produces antibodies to intrinsic factor and/or the parietal cells?
|
Pernicious anemia (due to a lack of RBC production)
|
|
How do chief cells stain and where are they found?
|
Basophilic since they are protein producing cells (secrete pepsinogen and lipases) - found mainly in the lower gland
|
|
Which cell secretes pepsinogen and what activates it?
|
cheif cells in lower gland secrete and HCl activates it
|
|
How can acid secretion by the parietal cells be reduced and what is a side effect of this treatment?
|
With proton pump inhibitors or histamine receptor blockers (Tagamet, Zantac) - lack of HCl reduces activation of pepsinogen and decreases digestion
|
|
How do neuroendocrine cells stain and where are they found
|
Only their nucleus stains, their cytoplasm DOES NOT; they are found in the lower gland
|
|
What is secreted by the neuroendocrine cell and what is the associated pathology?
|
Ghrelin (stimulates hunger) - excessive production of ghrelin causes Prader-Willi syndrome (complex disease)
|
|
What cell mediates the formation of dysplasia in the stomach due to damage to the mucosa?
|
Stem cell - will form many intermediate type cells that have not fully differentiated yet
|
|
Short pits and short glands are found in what part of the stomach?
|
cardiac stomach
|
|
80. What characterizes the glands of the pyloric stomach and which two enzymes are specifically secreted in this area?
|
long pits, short glands (mainly mucous and neuroendocrine cells) - secrete somatostatin and gastrin
|
|
What infectious agent causes chronic gastritis and how does exert its action?
|
Helobacter pylori - very mobile, attaches to surface epithelium; causes inflammation, acid-induced ulceration and necrosis, fibrous scarring (obstruction due to scarring at lower esophagus or pylorus); also hemorrhage, perforation
|
|
In what syndrome are hyperplasia of the stomach and gastrin secreting tumors normally seen?
|
Zollinger-Ellison syndrome - causes high HCl secretion which can lead to diarrhea, steatorrhea, and gastric ulcers
|
|
What is the epithelial transition found going from stomach to small intestine (at the gastroduodenal junction)?
|
Simple columnar mucous secreting cells --> simple columnar absorptive cells (not a very abrupt transition = less dysplasia)
|
|
What happens to the muscularis externa at the gastroduodenal junction
|
oblique layer is lost, thickened circular layer = pyloric sphicter
|
|
What happens to the submucosa at the gastroduodenal junction
|
glands start appearing the duodenal part
|
|
What are the mucosal folds of the small intestine called
|
Plique - they are permanent irregardless of distension
|
|
Intestinal villi are finger-like extension of what structure?
|
lamina propria
|
|
What are the simple columnar absorptive cells of the small intestine called
|
enterocytes
|
|
What are some of the characteristics of the enterocyte?
|
microvilli with glycocalyx coat and digestive enzymes; lateral junctional complexes and plications; IgA endocytosis, glycoprotein coating and exocytosis
|
|
Which enzymes are secreted by the enterocyte
|
Disacharidases, peptidases, lipases, alkaline phosphatase
|
|
What are the intestinal glands also know as and what types of cells do they contain?
|
Crypts of Lieberkuhn - contain columnar absorptive cells, goblet cells, neuroendocrine cells, stem cells, Paneth cells, and microfold cells
|
|
What do the Paneth cells secrete and where are they located?
|
lysozymes (mainly), defensins, glycoproteins, located in the bottom of the intestinal glands
|
|
Where are microfold cells found and what is their purpose?
|
In the crypts of Lieberkuhn - squamous cells on discontinuous basal lamina, located over lymphoid nodules; antigen-presenting cells; may stimulate conversion of B cells to plasma cells
|
|
What is unique about the enterocytes of the duodenum?
|
they secrete enterokinase which activates pancreatic trypsin at the luminal surface
|
|
What structure distinguishes the duodenum from the other parts of the intestine?
|
Brunner's glands in the submucosa - secrete an alkaline mucous which buffers the incoming stomach acid
|
|
What do the neuroendocrine cells of the duodenum secrete?
|
secretin and CCK
|
|
What does secretin do?
|
stimulates pancreatic duct secretion of bicarbonate ions
|
|
What does cholecystokinin (CCK) do?
|
stimulates pancreatic secretion and contraction of smooth muscle in the gall bladder
|
|
What characterizes the jejunum?
|
Most pronounced plicae, very long villi, no Brunner’s glands or Peyer’s patches (nothing going on in the submucosa)
|
|
What characterizes the ileum?
|
Short broad villi, Peyer’s Patches in submucosa that extend into the lamina propria
|
|
What characterizes the mucosa of the large intestine?
|
Simple columnar absorptive cells, intestinal glands, lots of Goblet cells, stem cells, neuroendocrine cells; NO intestinal villi
|
|
What is unique about the lamina propria of the large intestine and what is the clinical significance?
|
Contains NO lymphatics - metastasis of colon cancer is slow
|
|
108. What is located beneath the epithelium basal lamina of the large intestine and what is its function?
|
Prominent layer of collagen and fibroblasts - regulates passage of water
|
|
Where in the large intestine is lymphoid tissue found?
|
in the submucosa (diffuse lymphoid tissue and nodules extend into the lamina propria)
|
|
What is unique about the outer longitudinal layer of the muscularis externa of the large intestine?
|
It is bundles together into three sections called the teniae coli
|
|
What are the valve-like specializations called in the anal canal?
|
Anal columns of Morgagni (with anal sinuses)
|
|
What epithelial transition takes places at the pectinate line of the anal canal?
|
simple columnar ---> stratified squamous
|
|
What happens to the muscularis externa in the anal canal?
|
Outer longitudinal layer dissapears while inner circular layer thickens (= internal anal sphincter)
|
|
What are three causes of malabsorption syndromes?
|
brush border enzyme abnormalities
defective bile secretion abnormal pancreatic enzyme secretion |
|
What causes gluten enteropathy (celiac disease) and what characterizes it?
|
Immune-mediated inflammatory disease of small intestine (antibodies to gluten of wheat) - atrophy and flattening of intestinal villi, hyperplasia of intestinal glands (mainly affects jejunum)
|
|
What is the disease in which high intralumenal pressure (possibly due to low residue diet) and a weakened muscularis results in hernaition of mucosa through weakened muscularis?
|
Diverticular disease (complications include inflammation, perforation, hemorrhage)
|
|
What are some of the characteristic histological findings in Crohn's disease?
|
Domed areas of edematous mucosa and submucosa with fissured ulcers and granulomas; inflammation may be transmural and can lead to fibrosis and obstruction; predisposes to cancer
|
|
What characterizes the acute phase of ulcerative colitis?
|
Inflammation with neutrophils accumulating in lamina propria and crypts forming abcesses
|
|
What distinguishes ulcerative colitis from from other inflammatory bowel disease
|
Ulcerative colitis affects the colon and mainly the rectum; inflammation is RARELY transmural; inflammatory pseudopolyps
|
|
What is a pseudopolyp?
|
An area of normal mucosa projecting above the diseased mucosa
|
|
What can chronic cases of ulcerative colitis lead to?
|
Dysplasia and adenocarcinoma
|
|
What is the most frequent site of adenocarcinoma in the large interstine?
|
sigmoid colon
|
|
How are colon polyps characterized and which type has the most potential for neoplasia?
|
tubular, tubulovillus, villi (most potential for neoplasia)
|
|
How does the appendix appear histologically
|
Similar to colon except contains many aggregated lymphoid nodules in submucosa and lamina propria; distinguished from ileum by its lack of intestinal villi
|
|
In appendicitis, what area is normally affected by peritonitis (before rupture)?
|
right iliac fossa
|
|
In the classic liver lobule, what lies centrally, what radiates out from the center, what penetrates between the horizontal plates, and what's located at the corners of the hexagon?
|
respectively: central vein, hepatocytes, liver sinusoids, portal space containing the portal triad
|
|
What structures are located in the portal triad?
|
interlobular portal vein, hepatic artery, bile duct
|
|
What type of cells make up the mass of the liver sinusoids and what structure ties those cells together?
|
sinusoidal capillaries with absent or discontinuous basal lamina - phagocytic Kupferr cell span the gaps b/w them
|
|
Where is the space of Disse found and what is contained within it?
|
b/w the hepatocytes and sinusoid - contains stellate cells
|
|
What are the stellate cells found in the space of Disse also known as and what is their function?
|
fat-storing cells of Ito - involved in vitamin A storage; possess a contractile function (decreases vascular resistance of sinusoids); synthesizes reticular fibers (regeneration) and collagen fibers (disease conditions, fibrosis)
|
|
Which liver cell has the capability to cause overproduction of collagen, leading to liver fibrosis?
|
fat-storing cells of Ito (stellate cells)
|
|
What is the path that portal blood flow takes within the liver?
|
portal vein splits into interlobular portal veins --> meet with interlobular portal arteries in portal triad --> arterial and venous blood mixes as it passes though the sinusoids toward the central vein --> central veins join to form sublobular veins --> hepatic veins --> IVC
|
|
What is the functional unit of the liver based on blood flow, what lies at its central axis, and what do the hepatocytes converge into laterally?
|
hepatic acinus; interlobular vessels on central axis; hepatocytes converge on central veins (creating zones 1-3)
|
|
What characterizes the hepatocytes in zone 1 of the hepatic acinus?
|
the most oxygenated; most metabolically active; first to store and release glycogen; first to be exposed to metabolites and toxins; first to suffer toxic injury
|
|
What characterizes the hepatocytes of zones 2 and 3?
|
zone 2: intermediate layer
zone 3: lowest metabolism, first to be affected by ischemia |
|
What are the components of bile?
|
bile acids, bilirubin, phospholipids, electrolytes and water
|
|
What percent of bile acids are re-circulated via venous blood of the GI tract?
|
90%
|
|
Where and how are bile acids synthesized?
|
in the sER of hepatocyte
cholesterol --> cholic acid --> conjugates with AA --> bile acid secreted into the canaliculi |
|
Where and how is bilirubin synthesized?
|
spleen macrophages (primary site) and liver kupffer cells
RBCs phagocytosed --> break-down of Hb --> hydrophobic bilirubin --> hepatocytes conjugate to form water-soluble bilirubin --> secreted into the canaliculi |
|
What forms the hepatic canaliculi?
|
minute gaps b/w adjacent hepatocyte plasma membranes forming junctional complexes
|
|
How does bile flow?
|
opposite of blood flow
canaliculi --> collecting ductules --> interlobular bile ducts of portal triad --> larger ducts --> hepatic ducts |
|
What epithelial change occurs between the collecting ductules of bile flow and the hepatic ducts?
|
cuboid --> columnar --> stratified columnar
|
|
What does the connective tissue framework of the liver consist of?
|
reticular fibers around hepatocytes and sinusoids; loose and dense CT around vessels and ducts; thin CT capsule = serosa
|
|
What usually accompanies regeneration of the liver?
|
fibrosis of the liver - while reticular fibers are made so it collagen
|
|
What are the 8 main functions of the hepatocyte?
|
syn of plasma proteins; metabolite storage and release; detoxification and inactivation of toxins; iron storage; blood formation; handles vitamins and endocrine function
|
|
What metabolic processes occur in the sER of the hepatocyte?
|
Gluconeogenesis; AA deamination --> urea; glucose <--> glycogen
|
|
147. Where in the liver does detoxification and inactivation of toxins occur and what specific processes are performed at each location?
|
sER: oxidation and conjugation; peroxisomes: oxidation and catabolism; lysosomes: digestion of waste and iron storage
|
|
What cell synthesizes the majority of enzymes involved in iron transport?
|
hepatocytes
|
|
In the fetus, where does blood formation occur?
|
in the space of disse
|
|
Regarding vitamins, what processes occur in the liver?
|
storage and maintenace of vitamin A; conversion of vitamin D to circulating form; absorption, metabolism, and secretion of vitamin K
|
|
What is the specific endocrine function of the liver?
|
conversion of T4 --> T3; secretion of GH releasing factor; degradation of insulin and glucagon
|
|
After some toxic insult to the liver (heavy drinking, drugs) , what part of the liver will show the most proliferation?
|
sER of hepatocyte
|
|
What are some examples of genetic storage diseases affecting the liver?
|
Glycogen storage disease, lipidoses, mucopolysaccharidoses, haemochromatoses
|
|
What are causes of acute hepatitis and what effects will it have on the liver?
|
Toxins, alcohol, drugs, viral agents (!) - hydropic degeneration of hepatocytes, progresses to spotty necrosis with aggregates of inflammatory cells around necrotic hepatocytes (Councilman bodies); Kuppfer cell proliferation
|
|
What are necrotic hepatocytes called
|
councilman bodies
|
|
What are causes of chronic hepatitis and how is each case of disease rated?
|
Viral (!), toxins, autoimmune - classified according to how far it progresses (stage) and how active (grade)
|
|
What is the end stage of liver disease called and what characterizes it?
|
Cirrhosis - characterized by hepatocyte loss, regenerative nodules encased in CT, disruption in architecture affecting blood/bile flow
|
|
What is the major type of liver cancer called and why is the liver often affected?
|
hepatocellular carcinoma - common site for secondary metastasis from other cancers
|
|
What distinguishes the gall bladder from the small intestine histologically?
|
No Goblet cells in gall bladder - gall bladder muscularis is much thinner and irregular
|
|
What is the most important function of the gall bladder and how does it achieve it?
|
concentration of bile: mucosa consists of deep folds comprised of simple columnar absorptive cells that pump NaCl into intercellular space attracting water
|
|
When are the mucous glands of the lamina propria of the gall bladder most active?
|
during inflammation
|
|
What stimuli cause smooth muscle contraction and expulsion of stored bile?
|
ANS, cholecystokinin (CCK), gastrin
|
|
What are gall stones also known as and what are they made up of?
|
Calculi - solid concretions of cholesterol (80% of cases) or of bile which attract calcium and salt deposits
|
|
When gall stones block the common bile duct, what results?
|
obstructive jaundice
|
|
Blockage of the cystic duct will lead to what disease and how is it characterized?
|
Cholecystitis (inflammation of the gall bladder) - gall bladder muscle contracts in an effort to expel bile; muscularis increases in thickness; increased pressure in gallbladder lumen forces mucosa into muscularis creating Rokitansky-Aschoff sinuses
|
|
What are causes of chronic hepatitis and how is each case of disease rated?
|
Viral (!), toxins, autoimmune - classified according to how far it progresses (stage) and how active (grade)
|
|
What is the end stage of liver disease called and what characterizes it?
|
Cirrhosis - characterized by hepatocyte loss, regenerative nodules encased in CT, disruption in architecture affecting blood/bile flow
|
|
What is the major type of liver cancer called and why is the liver often affected?
|
hepatocellular carcinoma - common site for secondary metastasis from other cancers
|
|
What distinguishes the gall bladder from the small intestine histologically?
|
No Goblet cells in gall bladder - gall bladder muscularis is much thinner and irregular
|
|
What is the most important function of the gall bladder and how does it achieve it?
|
concentration of bile: mucosa consists of deep folds comprised of simple columnar absorptive cells that pump NaCl into intercellular space attracting water
|
|
When are the mucous glands of the lamina propria of the gall bladder most active?
|
during inflammation
|
|
What stimuli cause smooth muscle contraction and expulsion of stored bile?
|
ANS, cholecystokinin (CCK), gastrin
|
|
What are gall stones also known as and what are they made up of?
|
Calculi - solid concretions of cholesterol (80% of cases) or of bile which attract calcium and salt deposits
|
|
When gall stones block the common bile duct, what results?
|
obstructive jaundice
|
|
Blockage of the cystic duct will lead to what disease and how is it characterized?
|
Cholecystitis (inflammation of the gall bladder) - gall bladder muscle contracts in an effort to expel bile; muscularis increases in thickness; increased pressure in gallbladder lumen forces mucosa into muscularis creating Rokitansky-Aschoff sinuses
|
|
What makes up the exocrine portion of the pancreas?
|
compound acinar glands composed of acinar cells with protein-secreting cellular characteristics and zymogen granules
|
|
What distinguishes the pancreas from the parotid gland histologically?
|
Pancreas contains pale-staining Islets of Langerhans; intralobular ducts of pancreas contain columnar cells that are NOT striated
|
|
What are some of the digestive enzymes secreted by the exocrine portion of the pancreas?
|
Proteolytic enzymes, amylase, lipases, ribonucleases, deoxyribonucleases
|
|
What is at the end of the intercalated pancreatic ducts?
|
centroacinar cells
|
|
What distinguishes the pancreas at the EM level?
|
Lots of zymogen granules
|
|
Why is pancreatitis a severe illness?
|
Release of pancreatic enzymes causes chemical peritonitis as well as hemorrhage and necrosis of the pancreas and surrounding tissues (high mortality rate)
|
|
After centrifugation of blood, what three layers form and what is contained within each?
|
top layer: plasma
middle layer: buffy coat (WBCs, platelets) bottom layer: erythrocytes (hematocrit) |
|
What are the normal constituents of plasma?
|
albumin, fibrinogen, immunoglobulins, coagulation proteins, lipoproteins, carrier proteins, mineral salts, water
|
|
What distinguishes plasma from serum?
|
Serum does NOT contain fibrinogen (obtained when blood is collected without an anticoagulant)
|
|
What are two common WBC stains?
|
Romanovsky or Wright stains
|
|
What makes up the exocrine portion of the pancreas?
|
compound acinar glands composed of acinar cells with protein-secreting cellular characteristics and zymogen granules
|
|
What distinguishes the pancreas from the parotid gland histologically?
|
Pancreas contains pale-staining Islets of Langerhans; intralobular ducts of pancreas contain columnar cells that are NOT striated
|
|
What are some of the digestive enzymes secreted by the exocrine portion of the pancreas?
|
Proteolytic enzymes, amylase, lipases, ribonucleases, deoxyribonucleases
|
|
What is at the end of the intercalated pancreatic ducts?
|
centroacinar cells
|
|
What distinguishes the pancreas at the EM level?
|
Lots of zymogen granules
|
|
Why is pancreatitis a severe illness?
|
Release of pancreatic enzymes causes chemical peritonitis as well as hemorrhage and necrosis of the pancreas and surrounding tissues (high mortality rate)
|
|
After centrifugation of blood, what three layers form and what is contained within each?
|
top layer: plasma
middle layer: buffy coat (WBCs, platelets) bottom layer: erythrocytes (hematocrit) |
|
What are the normal constituents of plasma?
|
albumin, fibrinogen, immunoglobulins, coagulation proteins, lipoproteins, carrier proteins, mineral salts, water
|
|
What distinguishes plasma from serum?
|
Serum does NOT contain fibrinogen (obtained when blood is collected without an anticoagulant)
|
|
What are two common WBC stains?
|
Romanovsky or Wright stains
|
|
What are the C, D, and E antibodies collectively referred to?
|
Rh factor
|
|
What is the disease called where the mother's Rh antibodies stage an attack against her second child?
|
Hemolytic disease of the newborn (erythroblastosis fetalis)
|
|
What determines RBC production?
|
Hormones (erythropoeitin), blood loss (hemorrhage), hypoxia
|
|
What is the definition of anemia and what can cause it?
|
a decrease in the oxygen carrying capacity of blood - decrease in the number of red blood cells, defective hemoglobin
|
|
What is polycythemia?
|
increased erythrocyte count
|
|
What type of granules are contained within ALL leukocytes and what distinguishes the granular from the agranular?
|
all contain azurophilic granules which are primary lysozomes - granular leukocytes also contain larger specific granules which contain different enzymes and other constituents
|
|
What is the most common leukocyte and what distinguishes it?
|
neutrophil (60-70%) - has a segmented nucleus and amboid movement
|
|
What are some of the specific granules found in the neutrophil?
|
collagenase, alkaline phosphatase, and bacteriocidal enzymes; also contain glycogen allowing for anaerobic glycolysis
|
|
Which white blood cells form the first line of defense?
|
neutrophil - most phagocytic, form puss in infected site
|
|
What is meant by the "rolling mechanism" of leukocytes?
|
process mediated by cellular adhesion molecules by which WBC adhere to endothelial cells of the inner vessel wall and pass through the vessels by diapedesis
|
|
What are the C, D, and E antibodies collectively referred to?
|
Rh factor
|
|
What is the disease called where the mother's Rh antibodies stage an attack against her second child?
|
Hemolytic disease of the newborn (erythroblastosis fetalis)
|
|
What determines RBC production?
|
Hormones (erythropoeitin), blood loss (hemorrhage), hypoxia
|
|
What is the definition of anemia and what can cause it?
|
a decrease in the oxygen carrying capacity of blood - decrease in the number of red blood cells, defective hemoglobin
|
|
What is polycythemia?
|
increased erythrocyte count
|
|
What type of granules are contained within ALL leukocytes and what distinguishes the granular from the agranular?
|
all contain azurophilic granules which are primary lysozomes - granular leukocytes also contain larger specific granules which contain different enzymes and other constituents
|
|
What is the most common leukocyte and what distinguishes it?
|
neutrophil (60-70%) - has a segmented nucleus and amboid movement
|
|
What are some of the specific granules found in the neutrophil?
|
collagenase, alkaline phosphatase, and bacteriocidal enzymes; also contain glycogen allowing for anaerobic glycolysis
|
|
Which white blood cells form the first line of defense?
|
neutrophil - most phagocytic, form puss in infected site
|
|
What is meant by the "rolling mechanism" of leukocytes?
|
process mediated by cellular adhesion molecules by which WBC adhere to endothelial cells of the inner vessel wall and pass through the vessels by diapedesis
|
|
What are the C, D, and E antibodies collectively referred to?
|
Rh factor
|
|
What is the disease called where the mother's Rh antibodies stage an attack against her second child?
|
Hemolytic disease of the newborn (erythroblastosis fetalis)
|
|
What determines RBC production?
|
Hormones (erythropoeitin), blood loss (hemorrhage), hypoxia
|
|
What is the definition of anemia and what can cause it?
|
a decrease in the oxygen carrying capacity of blood - decrease in the number of red blood cells, defective hemoglobin
|
|
What is polycythemia?
|
increased erythrocyte count
|
|
What type of granules are contained within ALL leukocytes and what distinguishes the granular from the agranular?
|
all contain azurophilic granules which are primary lysozomes - granular leukocytes also contain larger specific granules which contain different enzymes and other constituents
|
|
What is the most common leukocyte and what distinguishes it?
|
neutrophil (60-70%) - has a segmented nucleus and amboid movement
|
|
What are some of the specific granules found in the neutrophil?
|
collagenase, alkaline phosphatase, and bacteriocidal enzymes; also contain glycogen allowing for anaerobic glycolysis
|
|
Which white blood cells form the first line of defense?
|
neutrophil - most phagocytic, form puss in infected site
|
|
What is meant by the "rolling mechanism" of leukocytes?
|
process mediated by cellular adhesion molecules by which WBC adhere to endothelial cells of the inner vessel wall and pass through the vessels by diapedesis
|
|
What is the process called where WBCs travel to the site of infection through the use of chemoattractants and matrix proteins?
|
"Homing mechanism" (chemotaxis)
|
|
What characterizes the eosinophil histologically and what percent of WBCs do they comprise?
|
bi-lobed nucleus, 1-5%
|
|
What are the specific granules found inside the eosinophil?
|
acidophilic granules: bacteriocidal enzymes, acid phospatase, major basic protein
|
|
What is main function of the eosinophil?
|
killer of parasites,(via major basic protein), active in allergic reactions (phagocytose the antibody-antigen immune complex)
|
|
What distinguishes the eosinophils on the EM level?
|
Granules have crystalloid core - as opposed to basophils who don't have a crystalloid core
|
|
Which WBCs are the least numerous of the granulocytes and how are the characterized histologically?
|
basophils - bilobed, obscured nucleus
|
|
What are the specific granules found in the basophil and what cell is the basophil similar to in function?
|
basophilc granules: heperin, histamine, eosinophilic chemotactic factor - similar to mast cells
|
|
What are the two main types of agranular leukocytes?
|
monocyte and lymphocyte
|
|
What distinguishes a monocyte histologically and what is its function?
|
large cell w/ indented nucleus, can differentiate into macrophages, microglia, osteoclasts and kupffer cells
|
|
What are the three main types of lymphocytes and what percent of WBCs do they comprise together?
|
T lymphocyte, B lymphocyte, Natural Killer cells (NK) - 20-40% of WBCs
|
|
What characterizes the lymphocytes histologically?
|
Round nucleus (B & T cells) or kidney-shaped nucleus (NK cells) and a thin rim of cytoplasm
|
|
What is the function of the lymphocytes, specifically?
|
B lymphocytes (humoral immunity) and T lymphocytes (cellular immunity) function in adaptive [aquired] immunity responses; NK cells are part of the innate system
|
|
Where do B and T lymphocytes mature, respectively?
|
blood, thymus
|
|
What cell are platelets derived from?
|
megakaryocytes
|
|
What are the layers of the platelet called from outer to inner?
|
outer cell coat, marginal zone, peripheral zone, inner zone
|
|
What molecules are found in the outer cell coat of the platelet?
|
glycoproteins that functin in cellular adhesion
|
|
What molecules are found in the marginal bundle of the platelet?
|
microtubules
|
|
What is the peripheral zone of the platelet also known as and what is found in this zone?
|
Hyalomere - contains actin and myosin which function in platelet movement and clot retraction
|
|
What is the inner zone of the platelet also known as and what is found in this zone?
|
granulomere - consists of granules which contain platelet-specific proteins, lysosomal enzymes, and granules which store seritonin taken up from plasma
|
|
What are two commonly known coagulation proteins associated with the platelet and what are their associated pathologies?
|
Von Willebrand Factor associated with factor VIII (Hemophilia Type A: defective or deficient factor VIII); glycoprotein 1b-factor IX (Hemophilia Type B)
|
|
What is the clinical term for decrease platelets and what are its causes?
|
Thrombocytopenia - caused by decreased production or increased destruction of platelets; induced by drugs or autoantibodies to platelets or megakaryocytes
|
|
In what three classes can endocrine hormones be subdivided?
|
AA derivatives
peptides steroids |
|
By what two mechanisms of action can endocrine hormones exert their effects?
|
trophic hormones: modulate secretory activity of other endocrine glands
direct-acting hormones: stimulate changes in non-endocrine tissue |
|
What are the three categories that describe control of hormone secretion?
|
hormonal
humoral neural |
|
What are some of the general histologcial features associated with endocrine organs?
|
CT capsule, septa, and stroma; reticular fiber framework that surrounds glandular cells and capillaries; highly vascular - fenestrated capillaries
|
|
What are the general functions of the hypothalamus?
|
neuroendocrine regulation: autonomic control over the adrenal medulla; neuronal synthesis of hormones for the posterior pituitary; secretion of regulatory hormones affecting the anterior pituitary
|
|
What are the two nuclei that comprise the pars nervosa (post. pituitary) and what do they synthesize?
|
supraoptic nucleus: ADH
paraventricular nucleus: oxytocin |
|
What is the posterior pituitary developed from?
|
a downgrowth of the hypothalamus - neuroectoderm
|
|
What is another name for the pituitary stalk?
|
infundibulum
|
|
What are the support cells of the posterior pituitary gland called?
|
pituicytes (glial cells)
|
|
What are Herring bodies?
|
secretory granules in dilated axon terminals of posterior pituitary
|
|
What is the pathophysiology of diabetes insipidus and what is its main cause?
|
genetic defects in the receptors for ADH or nonresponsive receptors for ADH causing chronic renal disease - usually caused by a pituitary tumor
|
|
What effects does oxytocin have on the body?
|
Myoepithelial cell contraction in mammary gland, contraction of uterine smooth muscle during labor
|
|
Where does ADH exert its effects?
|
collecting ducts and DCT (insertion of aquaporins)
|
|
What is the anterior pituitary developed from?
|
outpocket of the oral ectoderm - Rathke's pouch
|
|
What is the part of the anterior pituitary called that partially enwraps the infundibulum?
|
pars tuberalis
|
|
What is the area of the anterior pituitary called that contains epithelial cysts and what are they created by?
|
Pars intermedia - remnants of Rathke's pouch
|
|
In what part of the anterior pituitary are most of the secretory cells located?
|
pars distalis
|
|
Secretory cells in the pars intermedia secrete what?
|
melanocyte stimulating hormone (MSH) and a small amount of ATCH
|
|
What do the chromophobes of the pars distalis consist of?
|
stem cells and support cells
|
|
What are the chromophils of the pars distalis and how are they classified?
|
acidophils: GH, prolactin
basophils: ACTH, TSH, FSH, LH |
|
What is secreted by somatotrophs in the anterior pituitary, what are its releasing factors, and what are its effects?
|
GH, secreted in response to GH-releasing factor and somatostatin, stimulates liver production of insulin-like growth factor-1 which stim cell growth and protein syn in most of the body tissues, esp bone
|
|
228. What does decreased GH, increased GH in children, and increased GH in adults cause, respectively?
|
Dwarfism, gigantism, acromegaly
|
|
What is the most common cause of acromegaly and what are some of the associated signs?
|
Pituitary tumor - signs: spade-shaped hands and feet, prominent supraorbital ridge, joint pain, peripheral neuropathy, hypertension
|
|
What is secreted by mammotrophs in the anterior pituitary, what are its releasing factors, and what are its effects?
|
prolactin, secreted in response to PR factor and thyrotropin releasing factor, stim milk production and growth and development of mammary gland during pregnancy
|
|
What are three inhibiting factors of prolactin?
|
dopamine, estrogen, progesterone
|
|
What signs and symptoms are associated with a prolactin-secreting tumor?
|
Anovulation in females; decreased libido; infertility and galactorrhea in males
|
|
What is secreted by corticotrophs in the anterior pituitary, what is its releasing factor, and what are its effects?
|
ACTH, secreted in response to corticotropin releasing factor, stim secretion by adrenal medulla cells (mainly cortisol)
|
|
What is secreted by thyrotrophs in the anterior pituitary, what is its releasing factor, and what are its effects?
|
TSH, secreted in response to TRH, stim follicle cells of thyroid to secrete T3 and T4
|
|
What inhibits the secretion of TSH?
|
T3, T4 negative feedback mechanism
|
|
What is secreted by gonadotrophs in the anterior pituitary, what is its releasing factor, and what are its effects?
|
FSH and LH, secreted in response to GnRH
|
|
What pathology can influence the release of gonadotropins?
|
Pituitary tumors; anorexia (can decrease secretion of gonadotropin-releasing factor causing decreased fertility in females and hypogonadism in males)
|
|
What two arteries supply the pituitary gland and what does each do specifically?
|
inferior hypophyseal a --> pars nervosa
superior hypophyseal a. --> hypothalamus, infundibulum, pars tuberalis, anterior pituitary (via portal veins) |
|
What is the narrow part of the thyroid gland called?
|
isthmus
|
|
What are the two secretory cells of the thyroid gland?
|
follicle cells, and parafollicle cells
|
|
What differentiates the active thryroid follicle from the inactive?
|
cells are more cuboidal in shape and there is a decreased number in the amount of stored colloid
|
|
What does the colloid of the thyroid follicle cell consist of what is its function?
|
thryoglobulin: glycoprotein complexed w/ T3 and T4
|
|
What is synthesized by the follicle cells of the thyroid gland?
|
tri-iodothyronine (T3) and tetra-iodothyronine (T4)
|
|
What is the only endocrine gland that stores is secretory product outside of the cell?
|
thyroid gland
|
|
How is thyroglobulin synthesized?
|
iodide is pumped into the thyroid follicle cell and oxidized to iodine at the apical plasma membrane --> thyroglobulin is then iodinated in the colloid at the apical surface
|
|
What happens physiologically when TSH stimulates the thyroid follicle cells?
|
endocytosis of thryoglobulin from the colloid --> thyroglobulin fuses with lysosome --> T3 and T4 are cleaved and secreted
|
|
What is the function of the thyroid parafollicle cells and what activates them?
|
secretion of calcitonin [inhibits osteoclast bone absorption, stimulates osteoblasts] induced by high blood calcium
|
|
What is cretinism and what is its associated pathology?
|
congenital deficiency in the secretion of thyroxine - leads to profound neurological damage (also dry skin, swollen face and tongue, umbilical hernia)
|
|
What is the most common type of hyperthyroidism and what causes it?
|
grave's disease - autoimmune disease in which antibodies to TSH receptors mimic TSH and chronically activate the thyroid gland
|
|
What is one of the main forms of hypothyroidism and what causes it?
|
Hashimoto's disease - autoimmune disease in which antibodies to thyroglobulin cause destruction of follicles
|
|
What characterizes a patient with Hashimoto's disease?
|
(around middle age/more common in women) - Decreased cell metabolism, mental lethargy, hypothermia, myxedema
|
|
What are the two cell types found in the parathyroid gland and what does each secrete?
|
cheif (principle) cells and secrete PTH
oxyphils - form of principle cells, contains a lot of mitochondrial waste |
|
As the parathyroid gland ages, what changes occur?
|
CT and adipose infiltrate the PT gland
|
|
What is the function of PTH?
|
most important molecule that regulates blood calcium levels: low blood calcium --> PTH secretion --> stim osteoclast resorption, increases renal tubular reabsorption of calcium, increases small intestine absorption of calcium
|
|
What pathology can cause of dysfunction of the parathyroid gland?
|
Genetic mutation of chief cells (cells can’t sense calcium levels which can lead to hyper- or hypoparathyroidism); benign adenomas can cause hyperparathyroidism (increased PTH causes increased bone demineralization and calcium excretion - leads to renal calculi); idiopathic hypoparathyroidism (tissues don’t respond to PTH)
|
|
From what two sources is the adrenal gland derived?
|
cortex: mesoderm
medulla: neural crest cells |
|
What is the function of the thyroid parafollicle cells and what activates them?
|
secretion of calcitonin [inhibits osteoclast bone absorption, stimulates osteoblasts] induced by high blood calcium
|
|
What is cretinism and what is its associated pathology?
|
congenital deficiency in the secretion of thyroxine - leads to profound neurological damage (also dry skin, swollen face and tongue, umbilical hernia)
|
|
What is the most common type of hyperthyroidism and what causes it?
|
grave's disease - autoimmune disease in which antibodies to TSH receptors mimic TSH and chronically activate the thyroid gland
|
|
What is one of the main forms of hypothyroidism and what causes it?
|
Hashimoto's disease - autoimmune disease in which antibodies to thyroglobulin cause destruction of follicles
|
|
What characterizes a patient with Hashimoto's disease?
|
(around middle age/more common in women) - Decreased cell metabolism, mental lethargy, hypothermia, myxedema
|
|
What are the two cell types found in the parathyroid gland and what does each secrete?
|
cheif (principle) cells and secrete PTH
oxyphils - form of principle cells, contains a lot of mitochondrial waste |
|
As the parathyroid gland ages, what changes occur?
|
CT and adipose infiltrate the PT gland
|
|
What is the function of PTH?
|
most important molecule that regulates blood calcium levels: low blood calcium --> PTH secretion --> stim osteoclast resorption, increases renal tubular reabsorption of calcium, increases small intestine absorption of calcium
|
|
What pathology can cause of dysfunction of the parathyroid gland?
|
Genetic mutation of chief cells (cells can’t sense calcium levels which can lead to hyper- or hypoparathyroidism); benign adenomas can cause hyperparathyroidism (increased PTH causes increased bone demineralization and calcium excretion - leads to renal calculi); idiopathic hypoparathyroidism (tissues don’t respond to PTH)
|
|
From what two sources is the adrenal gland derived?
|
cortex: mesoderm
medulla: neural crest cells |
|
What are the three zones of the adrenal cortex from outside in?
|
zona glomerulosa
zone fasiciculata zona reticularis (GFR - salt, sweet, sex) |
|
What is the morphology of the cells in the zona glomerulosa and what do they secrete?
|
packed clusters or columns of cells - secrete mineralcorticoids, mainly aldosterone
|
|
What is the action of aldosterone and what stimulates its secretion?
|
maintain salt conc in the body by increasing absorption of Na in the DCT of the kidney, sweat gland and intestines at the expense of potassium stim by low salt conc in the body and low BP
|
|
What is the morphology of the cells in the zona fasciculata and what do they secrete?
|
long straight columns of foamy cells - secrete glucocorticoids (mainly cortisol)
|
|
How is cortisol activated, what is its action, and what stimulates its secretion?
|
converted into cortisone by hepatocytes; promotes glucose metabolism in the liver and promotes lipid and protein degradation; also have anti-inflammatory fcn and suppresses the immune response; secretion stim by ATCH
|
|
What is the morphology of the cells in the zona reticularis and what do they secrete?
|
anastomosing cord of cells - secrete androgens dehydroepiandrosterone:DHEA, androstenedione
|
|
What are androgens converted into in peripheral tissues and what is their importance in post-menopausal women?
|
testosterone and estrogen - in post-menopausal women the zona reticularis becomes the main source of estrogen
|
|
What is synthesized by the fetal adrenal cortex during early gestation?
|
Dehydroepiandosterone which is a precursor to placental hormones
|
|
What happens to the fetal adrenal cortex during the development?
|
it degenerates and is replaced by the adult adrenal cortex
|
|
What causes Cushing's syndrome and how does it relate to Cushing's disease?
|
cushing's syndrome is caused by long term exposure to excessive glucocorticoids, cushing's disease is specifically caused by an ACTH-producing tumor in the pituitary gland
|
|
268. In what syndrome does the patient present with moon facies, osteoporosis, a buffalo hump, obesity, and amenorrhea?
|
cushing's syndrome
|
|
What characterizes the pathology of Cushing's syndrome?
|
Overproduction of cortisol leads to fat redistribution and muscle wasting as well as immunosuppression; also increased androgen secretion
|
|
What causes Addison's disease and what are some of the associated signs?
|
chronic destruction of cortex caused by autoimmune responses to TB - increased ATCH levels due to cortisol deficiency cause hypotension, muscle weakness, and increased skin pigmentation
|
|
What is the main cell type present in the adrenal medulla and what is it derived from?
|
chromaffin cells - derived from neural crest cells -->> modified sympathetic postganglionic neurons
|
|
What do the chromaffin cells synthesize and secrete?
|
epinephrine and norepinephrine
|
|
What separates the Islets of Langerhans from the surrounding pancreatic acinar cells?
|
reticular fibers and a network of capillaries
|
|
What are the main cell types that make up the pancreatic islets (of Langerhans) and what does each produce?
|
alpha: glucagon
beta: insulin delta: somatostatin, gastrin F: pancreatic polypeptide (inhibits SS) |
|
Which pancreatic islet cell lies more centrally and which more in the periphery?
|
central: beta
periphery: alpha |
|
What stimulates beta cell synthesis and secretion of insulin?
|
glucose enters beta cell via GLUT-2, stim cell syn and secretion of insulin; GLUT-2 is an insulin-independent transporter
|
|
How does insulin exert its effects?
|
insulin binds to insulin receptors on body cells; it then triggers reactions that facilitates glucose uptake by body cells by a GLUT 4 transporter; the GLUT-4 is insulin-dependent
|
|
What is the pathway of insulin synthesis?
|
GER --> preproinsulin --> proinsulin --> cleaved and packaged in the golgo --> insulin transported by microtubules to cell surface and secreted
|
|
What is the pathophyisology behind Type I Diabetes mellitus?
|
autoimmune destruction of B cells causing absent or deficient insulin secretion
|
|
What is the pathophyiology behind Type II Diabetes mellitus?
|
insulin resistance of peripheral target tissues may be due to an increase in number of insulin receptors (takes more insulin to trigger a reaction) or deficient signaling of GLUT 4 transporters
|
|
What are some of the common symptoms associated with DM (both Type I and II)?
|
high blood glucose, excessive hunger, high glucose conc in the urine, frequent urination and excessive thirst
|
|
What is the pineal gland considered part of and what are its main cell types?
|
part of the epithalamus, consists on neurons, glia, and pinealocytes
|
|
What do the pinealocytes secrete and what is the function of this molecule?
|
melatonin - regulates sleep/wake cycles; inhibits hypothalmic release of GnRH which then inhibits the release of LH and FSH; may regulate the onset of puberty
|
|
What is melatonin derived from and what inhibits its secretion?
|
derived from seritonin and is inhibited by light
|
|
What is the pathway that light takes to inhibit melatonin secretion form the pineal gland?
|
light --> retina --> retinohypothalmic tract --> hypothalamic suprachiasmatic nucleus -->pineal gland
|
|
What are the concretions of the pineal gland called that increase with age?
|
corpora arencea (brain sand): precipitation of calcium phosphates and carbonates on carrier proteins
|
|
Why do people who work night-shifts have an increased risk of cancer?
|
Exposure to light during both day and night causes a decrease in melatonin; melatonin decreases cancer growth and spread
|
|
What are the earliest blood forming cells of the fetus and what other organs kick in a little later?
|
mesodermal cells from the yolk sac - then liver and spleen
|
|
When does bone ossification and formation of marrow cavities begin and when does marrow become the primary blood-forming organ?
|
2 months, 7 months gestation
|
|
What is the main type of capillary found in bone marrow and what does its CT stroma consist of?
|
sinusoidal capillary, CT consists of reticular fibers and cells, collagen, fibronectin, laminen and other proteoglycans
|
|
Which bone marrow is the active kind and where is it mainly located in adults?
|
red bone marrow, in flat bones and at the ends of long bones
|
|
What does yellow bone marrow consist of and what are its characteristics?
|
adipose, gradually replaces red marrow in most bones, but can convert back to active bone marrow in times of need
|
|
What is the main vessel supplying the bone marrow and what are its branches?
|
nutrient a. --> central longitudinal a. --> cortical capillaries and medually capillaries
|
|
How does the blood return from the medullary capillaries to the general circulation?
|
medullary capillaries --> meduallary venous sinuses --> central longitudinal v.
|
|
What two stem cell types can the pluripotent stem cell differentiate into?
|
lymphoid stem cells (B and T lymphocytes), myloid stem cells (all others)
|
|
What colony forming units (CFU/CFC) can the myeloid stem cell differentiate into?
|
granulocyte-macrophage CFU, eosinophil CFU, basophil CFU, megakaryocyte CFU, erythroid CFU
|
|
Neutrophils and monocytes are derived from which common CFU?
|
granulocyte-macrophage CFU
|
|
What are the 3 overlapping functions of growth factors, colony-stimulating factors, and hematopoietins regarding WBCs?
|
they stimulate proliferation of progenitor precursor cells, support differentiation, and enhance mature cell functoin
|
|
What is the main function of the erythroid CFU and its immediate offspring and what happens as this process continues?
|
hemoglobin synthesis, as Hb syn tapers off, there is a decerase in polyribosomes; the nucleus condenses and is evenutally extruded
|
|
What is the average lifespan of a reticulocyte and what distinguishes it?
|
~ 3 days, has a slight bluish tinge with Wright's stain due to remaining reticular matter (and some polyribosomes)
|
|
What does an increase in reticulocytes signify?
|
hemorrhaging, anemia, anything that promotes the need for more RBCs
|
|
What factors are needed for RBC production?
|
erythropoietin (stim production of globin), Vit B12, IF, folic acid, iron
|
|
What is the first thing produced in the basic maturation of WBCs?
|
azurophilic (lysozomal) granules, followed by production of specific granules
|
|
Through what compartments does the neutrophil travel as it matures and what happens in each?
|
bone marrow (meiosis, maturation, storage); blood (circulates or becomes sequestered in marginating compartment); CT compartment (through diapedesis)
|
|
How long does the average neutrophil circulate in the blood and how long does it remain in the CT after diapedesis?
|
circulation: 6-7 hours
CT: ~ 4 days |
|
What is the marginating compartment of the blood and what can be sequestered here?
|
blood of capillaries, neutrophils
|
|
What is neutrophilia and what can cause it?
|
increase in circulating neutrophils, caused by epinephrine, cortisol, infection, band cells
|
|
How do epinephrine and glucocorticoids cause neutrophilia, respectively?
|
epi: dilation of capillaries causes release of neutrophils from marginating compartment
cortisol: increase mitosis |
|
What is seen in chronic infection regarding neutrophils?
|
increased number of immature neutrophils released from bone marrow; clinically referred to as a "shift to the left"
|
|
What are band cells and what characterizes them morphologically?
|
immature neutrophils, have a curved-rod-shaped nucleus (not yet segmented)
|
|
How long are monocytes in the circulation and what do they differentiate into?
|
~ 8 hours; macrophages, microglia, kupffer cells, osteoclasts, langerhan cells
|
|
Where are lymphocytes formed and where do they differentiate?
|
formed in marrow - differention occur in thymus (T lymphocytes) and bone marrow/ GALT (B lymphocytes)
|
|
Where do B lymphocytes differentiate into plasma cells?
|
in the peripheral tissue, NOT bone marrow
|
|
What are the large multi-nucleated cells called that generate platelets and where are they located?
|
megakaryocytes - located just outside of sinusoidal capillaries of the bone marrow
|
|
How do platelets form from megakaryocytes?
|
invaginations of the megakaryocyte plasma membrane ramify to form demarcation membranes (canuliculi) around areas of cytoplasm; cellular processes of the megakaryocytes extend into marrow sinusoids and the demarcated areas are pinched off or shed into the blood stream
|
|
What blood-forming organ is a common site for metastasis of cancer and from where does the spread often come?
|
bone marrow - mets from breast, prostate, kidney, and lung, thyroid
|
|
What pathophysiological findings are associated with tumors of bone marrow (and specifically those from prostate mets)?
|
destruction of trabecular bone and osteolytic deposits - prostatic cancer stim growth of new woven bone with osteoclastic deposits
|
|
What is the pathophysiology associated with leukemia?
|
over proliferation of specific clones can result in excessive numbers of one type of leukocyte and/or deficiency of other types; there will be a malignancy in one particular cell lineage anywhere along its differentiation
|
|
In which type of leukemia does the neoplastic proliferation occur further along the cell line (in more mature cells)?
|
chronic - allows for normal production production of other WBCs, RBCs, and platelets
|
|
Which cells are affected in acute leukemia and why is this form more malignant?
|
immature "blast" cell (early in differentiation), since they are precursors for many cell lineages, most systems will be affected
|
|
What are the two parts of the human immune system and what is the key feature that distinguishes them?
|
innate (nonspecific) and specific/adaptive
|
|
What are NK cells and what do they do?
|
seperature class of lymphocyte that attack virus-infected cells or tumor cells (transformed cells)
|
|
Where do B lymphocytes differentiate into plasma cells?
|
in the peripheral tissue, NOT bone marrow
|
|
What are the large multi-nucleated cells called that generate platelets and where are they located?
|
megakaryocytes - located just outside of sinusoidal capillaries of the bone marrow
|
|
How do platelets form from megakaryocytes?
|
invaginations of the megakaryocyte plasma membrane ramify to form demarcation membranes (canuliculi) around areas of cytoplasm; cellular processes of the megakaryocytes extend into marrow sinusoids and the demarcated areas are pinched off or shed into the blood stream
|
|
What blood-forming organ is a common site for metastasis of cancer and from where does the spread often come?
|
bone marrow - mets from breast, prostate, kidney, and lung, thyroid
|
|
What pathophysiological findings are associated with tumors of bone marrow (and specifically those from prostate mets)?
|
destruction of trabecular bone and osteolytic deposits - prostatic cancer stim growth of new woven bone with osteoclastic deposits
|
|
What is the pathophysiology associated with leukemia?
|
over proliferation of specific clones can result in excessive numbers of one type of leukocyte and/or deficiency of other types; there will be a malignancy in one particular cell lineage anywhere along its differentiation
|
|
In which type of leukemia does the neoplastic proliferation occur further along the cell line (in more mature cells)?
|
chronic - allows for normal production production of other WBCs, RBCs, and platelets
|
|
Which cells are affected in acute leukemia and why is this form more malignant?
|
immature "blast" cell (early in differentiation), since they are precursors for many cell lineages, most systems will be affected
|
|
What are the two parts of the human immune system and what is the key feature that distinguishes them?
|
innate (nonspecific) and specific/adaptive
|
|
What are NK cells and what do they do?
|
seperature class of lymphocyte that attack virus-infected cells or tumor cells (transformed cells)
|
|
Where do B lymphocytes differentiate into plasma cells?
|
in the peripheral tissue, NOT bone marrow
|
|
What are the large multi-nucleated cells called that generate platelets and where are they located?
|
megakaryocytes - located just outside of sinusoidal capillaries of the bone marrow
|
|
How do platelets form from megakaryocytes?
|
invaginations of the megakaryocyte plasma membrane ramify to form demarcation membranes (canuliculi) around areas of cytoplasm; cellular processes of the megakaryocytes extend into marrow sinusoids and the demarcated areas are pinched off or shed into the blood stream
|
|
What blood-forming organ is a common site for metastasis of cancer and from where does the spread often come?
|
bone marrow - mets from breast, prostate, kidney, and lung, thyroid
|
|
What pathophysiological findings are associated with tumors of bone marrow (and specifically those from prostate mets)?
|
destruction of trabecular bone and osteolytic deposits - prostatic cancer stim growth of new woven bone with osteoclastic deposits
|
|
What is the pathophysiology associated with leukemia?
|
over proliferation of specific clones can result in excessive numbers of one type of leukocyte and/or deficiency of other types; there will be a malignancy in one particular cell lineage anywhere along its differentiation
|
|
In which type of leukemia does the neoplastic proliferation occur further along the cell line (in more mature cells)?
|
chronic - allows for normal production production of other WBCs, RBCs, and platelets
|
|
Which cells are affected in acute leukemia and why is this form more malignant?
|
immature "blast" cell (early in differentiation), since they are precursors for many cell lineages, most systems will be affected
|
|
What are the two parts of the human immune system and what is the key feature that distinguishes them?
|
innate (nonspecific) and specific/adaptive
|
|
What are NK cells and what do they do?
|
seperature class of lymphocyte that attack virus-infected cells or tumor cells (transformed cells)
|
|
What are examples of humoral factors of the adaptive immune system?
|
Immunoglobulins (antibodies, Ab): secreted by B cells; lymphokines (type of cytokine): secreted by T cells
|
|
What is the name for specific cell surface protein sequences that are found on all nucleated cells and platelets?
|
MHC - Major Histocompatibility Complex molecules (each individual has a different “fingerprint” arrangement of MHC molecules)
|
|
What does tolerance of the adaptive immune system refer to?
|
Lymphocytes undergo selection mechanisms that eliminate lymphocytes expressing receptors for self proteins
|
|
What does self-limitation of the adaptive immune system mean?
|
Once the foreign antigen is neutralized, the response ceases
|
|
What does the memory function of the adaptive immune system allow for?
|
After the first exposure to an antigen, memory cells and clonal expansion allow for rapid response
|
|
What does the concept of diversity refer to (regarding the adaptive immune system)?
|
Lymphocytes utilize molecular mechanisms to modify their receptors so that they can respond to a large number of different antigen domains
|
|
What does specificity of the adaptive immune system refer to?
|
Individual B and T cells recognize specific domains of antigens
|
|
What is the complement system?
|
Series of plasma proteins which, when activated, can lyse microorganisms and stimulate phagocytic cells
|
|
What are cytokines and what is their function?
|
Different classes of small proteins that are secreted by a variety of cells; are not antigen-specific but function to coordinate and enhance immune responses
|
|
What are humoral factors and what are examples of them regarding the innate immune system?
|
Substances secreted into the blood - cytokines, complement system
|
|
What are the two types of MHC molecules and what is each type's function?
|
MHC I: presents peptides derived from proteins produced from within the cell itself
MHC II: present peptides derived from proteins taken up by antigen-presenting cells |
|
What is the only place that MHC II molecules are found and what cell are they displayed to?
|
only from on APC and displayed to helper T cells
|
|
What must an antigen-presenting cell be capable of?
|
endocytosis (in order to take up foreign protein)
|
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What are some examples of cells that can act like APCs?
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Antigen-presenting cells: macrophages, Langerhans cells (in epidermis), B cells, thymic epithelial reticular cells, interdigitating dendritic cells
|
|
What cells are responsible for cell-mediated immunity?
|
T cells - b/c they actually bind to foreign antigens (complexed with MHC II)
|
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Besides TCR (T cell receptor), what else is expressed on the surface of the T cell and what their function?
|
clusters of differentiation molecules (CD) that also act as co-receptors and mediate T cell activation
|
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Where does the expression of CD (clusters of differentiation) molecules develop?
|
thymus
|
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What factors function in T cell activation and what is involved in this process?
|
binding of antigen-MHC complexes to TCRs alongs with CD molecule interactions - T cell activation involves cellular proliferation and secretion of cytokines (lymphokines)
|
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What factors function in T cell activation and what is involved in this process?
|
a variety of immune functions including activation of other T cells, NK cells, and stim of B cell proliferation and differentiation into plasma cells
|
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Which CD cells are found on the T Helper cells and what is their function?
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CD4+, secrete lymphokines which stim B cell proliferatioin into plasma cells as well as proliferation of memory B cells
|
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Which CD cells are found on the Cytotoxic T cells and what is their function?
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CD8+, recognize "abnormal" MCH I on transformed cells (infected, tumor, transplanted)
|
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By what two mechanisms do the Cytotoxic T cells destroy transformed cells?
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release perforins (induce cell memb damage); activate genes which regulate apoptosis in transformed cell)
|
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What is the function of suppressor T cells and memory T cells, respectively?
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decrease activity of T and B cells; enhance immune response during related exposure to foreign antigens
|
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What is the difference between immunoglobulins and antibodies?
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Ig can be either cell-bound or free; Ab are only free (B lymphocytes can respond to both)
|
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What does humoral immunity refer to?
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Abs secreted from plasma cells (circulating Abs bind to foreign antigens)
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What is the common name for glycoproteins which act as flexible adaptors which can bind to antigens as well as bind to phagocytic cells?
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antibodies
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What are the two functional parts of the antibody and what does each part bind to?
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Fab fragment binds to antigen; Fc fragment binds to phagocyte
|
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Which immunoglobulin is expressed by the immature B cell and what is its function?
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IgM (membrane-bound) complexes with IgAlpha and IgBeta, it acts as a B cell Receptor (BCR) and serves as an antigen binding site
|
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Which processes happen during B cell activation?
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an antigen binds to BCR and is endocytosed, partially digested and complexed with MHC II molecules; B cell then acts as a APC allowing helper T cells to bind the antigen
|
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Which immunoglobulin takes the place of IgM when the B cell matures?
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IgD (think D for differentiation), IgM is now free to be released into the blood
|
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What are the two membrane-bound immunoglobulins?
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IgM, IgD
|
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What is the key difference between B cells and plasma cells?
|
plasma cells can release immunoglobins into the blood and B cells cannot
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What is the most abundant antibody and what is its function?
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IgG - activates complement system
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What is the only antibody able to cross the placenta?
|
IgG
|
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Which antibody is found in body secretions?
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IgA
|
|
What is the function of IgE?
|
attaches to mast cells and basophils and mediate the release of histamine and heparin from these cells during an allergic response
|
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What happens during the secondary immune response?
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memory B and T cells undergo clonal expansion to produce many antigen specific cells that rapidly destroy foreign antigen
|
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Where are lymphocytes found?
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blood (circulating), CT (mainly lamina propria), lymphoid organs
|
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what is found in a lymph nodule
|
spherical accumulation of B cells; may be solitary, may be aggregates
|
|
How are active lymph nodules characterized?
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they possess pale, germinal centers (b/c proliferating lymphocytes have more cytoplasm)
|
|
What are some examples of non-lymphoid organs?
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MALT (mucosa associated lymphoid tissue): GALT (peyer's patches in the ileum), respiratory tract, genitourinary tract
|
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What are some examples of lymphoid organs?
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tonsils, spleen, lymph nodes, thymus
|
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What are the support cells and fibers found in lymphoid tissue?
|
reticular cells and fibers are found in all lymphoid organs except the thymus
|
|
What are the tonsils basically accumulations of?
|
MALT (but they have a partial CT capsule and surface epithelium)
|
|
What are the three locations that tonsils are found in?
|
palatine tonsils: 2 in the lateral walls of the oropharynx
pharyngeal tonsil: 1 in the posterior wall of the nasopharynx lingual tonsil: numerous, at the base of the tongue |
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What type of epithelium do the three types of tonsils have, respectively?
|
palatine: stratified squamous
pharyngeal: pseudostratifed columnar lingual: stratifed squamous |
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Which tonsil has deep crypts and which has 1 crypt associated with each tonsil?
|
palatine: deep crypts
lingual: 1 crypt/tonsil |
|
What is the site of T cell maturation and what percent of T cells die in this process?
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thymus, 95% die in the cortex
|
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What does it mean to become immunocompetent and where in the thymus do T cell achieve this ability?
|
cells can distinguish between self and non-self proteins, occurs in the cortex of the thymus (before entering the medulla)
|
|
When does the thymus stop growing and what happens to it at this point?
|
puberty, gradually regressed with adipocyte infiltration
|
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What is the support cell of the thymus and what differentiates it from the support cells of other lymhoid organs?
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thymic epithelial reticular cell - epithelial derived as opposed to CT derived
|
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What forms the cortical blood-thymus barrier, where is it located, and why is this barrier essential?
|
thymic epithelial reticular cells: only located in the cortex of the thymus, prevents immature T cells from being exposed to foreign antigens, becoming tolerant to them
|
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What can thymic epithelial reticular cells express and what can they secrete?
|
act as APC expressing MHC I and II - secrete cytokines and hormones that influence T cell development
|
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What are the concentric layers of epithelial reticular cells and keratin called that are found in the medulla of the thymus?
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Hassal's corpuscle's
|
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What type of capillary is found in the thymus?
|
continuous
|
|
Where are macrophages mainly located in the thymus?
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perivascular in the cortex
|
|
What happens in the outer cortex of the thymus?
|
T cells begin differentiation, expressing CD4 and CD8 molecules
|
|
Where in the thymus does positive and negative selection occur and what happens during each process?
|
inner cortex - positive selection: T cells that recognize MHC but do not react (bind) with self-antigens are allowed to mature (those that dont recognize MHC are eliminated by apoptosis); negative selection: T cells that recognize MHC but react to self-antigens are eliminated
|
|
How do immunocompetent T cells gain access to the general circulation?
|
they pass through the venules in the medulla
|
|
What distinguishes the lymph node from the tonsil, histologically?
|
lymph node has a CT capsule whereas the tonsil is surrounded by epithelium
|
|
What is found in the outer and inner cortex of the lymph nodule, respectively?
|
outer cortex: nodules (B cells)
inner cortex (paracortex): T cells |
|
What two structures are found in the medulla of the lymph node, and what is the function of each part?
|
cords: stacks of B cells, plasma cells, macrophages, follicular dendritic cells;
lymph sinuses: spaces b/w the cords, filled with lymph, surrounded by macrophages, reticular cells and fibers |
|
Where are follicular dendritic cells found and what is their function?
|
cords of lymph nodes - attract and retain antigen on their surface (not APC)
|
|
What is the path that lymph flow takes from afferent to efferent lymph vessel?
|
afferent lymphatic vessel --> subcapsular sinus --> trabecular sinuses (cortex) --> medullary sinus --> efferent lymphatic vessel
|
|
How do most lymphocytes enter the lymph node and through what specific structures do they gain access?
|
through the vasculature, not the lymph vessels - specifically they enter the medulla through high endothelial venules
|
|
Where are high endothelial venules found and what characterizes them?
|
found in the medulla of the lymph node. they are lined by cuboidal epithelium cells that have receptors that attract lymphocytes
|
|
What is the main function of the spleen?
|
to filter blood
|
|
What is the tissue of the spleen divided up in and what does each contain?
|
white pulp: periarterial lymphatic sheath (PALS), lymphoid nodules
red pulp: reticular fibers and cells which intermesh with the discontinuous basal laminas of sinusoidal capillaries forming a "cage" |
|
What does the PALS consist of what does it surround?
|
consists of T cells, surrounds central arteries and arterioles
|
|
What are the three places in the body where T cells are found?
|
Paracortex of the lymph node, PALS, thymus
|
|
What is the path that blood takes through the spleen?
|
splenic a. --> trabecular a. --> central a. -->penicillar arterioles --> sheathed arterioles --> percolates through red pulp --> red pulp sinuses --> pulp v. --> trabecullar v. --> splenic v.
|
|
Between what two blood vessels of the spleen lies the separation of white pulp and red pulp?
|
central arteries and arterioles (white pulp)
penicillar arterioles (red pulp) |
|
What is the key functional component of the sheathed capillaries/arterioles of the spleen?
|
they contain macrophages
|
|
What type of capillaries are found in the spleen?
|
sinusoidal
|
|
Where are splenic cords found and what is contained within them?
|
in the red pulp, contain many WBCs, many RBCs, macrophages, plasma cells
|
|
What are the functions of the spleen?
|
activation of B and T cells; plasma cell differentiation; antibody secretion; monocyte differntiation (--> macrophages); RBC breakdown (Hb breakdown products --> liver); blood cell production in embryo and some in adult; blood storage
|
|
How does the spleen break down RBCs?
|
as RBCs grow older, their memb become more ridgid and inflexable; while passing through the red pulp of the spleen, they have to pass through very small spaces, causing their fragile membranes to disenigrate
|
|
In follicular hyperplasia of the lymph node, which part of the node enlarges and which cells are the cause of this?
|
nodules in the outer cortex enlarge due to B cell proliferation
|
|
In PARAfollicular hyperplasia of the lymph node, which cells proliferate?
|
T cells (located in the paracortical zone)
|
|
What causes lymph node reactive hyperplasia, and what specifically causes dilation of the lymph node sinuses?
|
infection - increased macrophage activity causes dilation of the sinuses
|
|
What do most tumor cells arise from in non-Hodgkin's lymphoma and where does it usually manifest first?
|
arise from B cells, usually manifests first in the lymph nodes but may arise from any lymphoid tissue (very commonly in MALT)
|
|
Where does Hodgkin's lymphoma usually start and where to can it spread?
|
in lymph nodes - can spread to other lymphoid organs and bone marrow
|
|
What characterizes Hodgkin's lymphoma, histologically?
|
Reed-Sternberg Cells: tumor cells that usally arise from activated T cells (may also arise from activated B cells and macrophages)
|
|
What is another name for the base of the bony orbit?
|
Orbital margin
|
|
What structures traverse through the apex of the bony orbit (optic canal)?
|
CN II
retinal vessels opthalmic a. |
|
What bones comprise the bony orbit?
|
frontal, zygomatic, maxilla, lacrimal, ethmoid, sphenoid, palatine
|
|
On its way out of the bony orbit, what does the optic canal pierce through?
|
lesser wing of the sphenoid bone
|
|
What fissure lies between the greater and lesser wing of the sphenoid bone and what does it carry?
|
superior orbital fissure: CN III, IV, V1, VI, opthamic vv.
|
|
What does the inferior orbital groove become as it extends anteriorly?
|
infraorbital foramen
|
|
What structures pass through the infraorbital fissure, groove, and foramen?
|
CN V2 infraorbital nerves, infraorbital vessels, vein to pterygoid plexus
|
|
What structures pass through the supraorbital foramen?
|
supraorbital nerves and vessels
|
|
What structure lines the entire bony orbit?
|
periosteum
|
|
What does the periosteum extend into in the eyelids?
|
orbital septum
|
|
What is another name for the base of the bony orbit?
|
Orbital margin
|
|
What structures traverse through the apex of the bony orbit (optic canal)?
|
CN II
retinal vessels opthalmic a. |
|
What bones comprise the bony orbit?
|
frontal, zygomatic, maxilla, lacrimal, ethmoid, sphenoid, palatine
|
|
On its way out of the bony orbit, what does the optic canal pierce through?
|
lesser wing of the sphenoid bone
|
|
What fissure lies between the greater and lesser wing of the sphenoid bone and what does it carry?
|
superior orbital fissure: CN III, IV, V1, VI, opthamic vv.
|
|
What does the inferior orbital groove become as it extends anteriorly?
|
infraorbital foramen
|
|
What structures pass through the infraorbital fissure, groove, and foramen?
|
CN V2 infraorbital nerves, infraorbital vessels, vein to pterygoid plexus
|
|
What structures pass through the supraorbital foramen?
|
supraorbital nerves and vessels
|
|
What structure lines the entire bony orbit?
|
periosteum
|
|
What does the periosteum extend into in the eyelids?
|
orbital septum
|
|
What is the pathology called caused by infection of the sebacous glands on the outer part of the eyelids?
|
stye
|
|
What is the slit between the two eyelids called when they are closed?
|
palpebra fissure
|
|
What is another name for the medial and lateral angles of the eye?
|
medial and lateral canthi
|
|
What is the periosteum continuous with in regard to the eyeball?
|
Continuous with fascia of extraocular muscles and eyeball (bulbar sheath)
|
|
What is the periosteum continuous with posteriorly?
|
Periosteal layer of dura at optic canal and superior orbital fissure
|
|
What is the medial angle of the eyelids called that is devoid of eyelashes?
|
caruncle (with lacrimal lake where tears pool)
|
|
What are the names for the elevation and hole found in the lower eyelid?
|
lacrimal papillae and punctum
|
|
What layer forms a protective barrier for the eye with the eye is closed and where is its attachment?
|
periosteum, attaches to the tarsal plates
|
|
Where are the tarsal plates located and what do they consist of?
|
lies deep to the orbicularis oris muscle and consists of dense CT (attach to orbital septum and medial and lateral palpebra ligaments)
|
|
What are the tarsal glands and what do they secrete?
|
modified sebaceous glands secreting an oily substance which mixes with lacrimal fluid making it more viscous (doesnt evaporate quickly)
|
|
A blockage of the tarsal glands is called what?
|
chalazion (normally on the inside of the eye)
|
|
What are the three portion of the orbicularis oculi muscle and what innervates it?
|
palpebra portion, orbital portion, lacrimal portion, innervated by CN VII
|
|
What is the name of the muscle that inserts by a broad aponeurosis to the tarsal plate and what innervates it?
|
levator palpebrae superioris - CN III
|
|
What does ptosis mean?
|
droopy eyelid, due to problem with the levator palpebrae superioris
|
|
What muscles are located behind the aponeurosis of the levator palpebrae superioris and what type of innervation do they have?
|
superior tarsal muscles (smooth muscle) - sympathetic innervation
|
|
What is the name given to injury of the sympathetic trunk in the neck and what are the associated symptoms?
|
Horner's syndrome: partial ptosis, miosis (pupil constriction), enopthalmos (retraction of eye), ipsilateral anhidrosis, vasodilation
|
|
What is the thin mucous membrane called that covers the cornea and reflects onto the inner surface of the eyelids?
|
conjunctiva (form conjunctival sac when eyes are closed)
|
|
Where are the lacrimal glands and ducts found?
|
superior lateral aspect of the orbit
|
|
Where do tears travel once they have collected in the lacrimal lake?
|
lacrimal punctum --> lacrimal canuliculi --> lacrimal sac --> nasolacrimal duct --> nasal cavity
|
|
How does the orbicularis oculi assist in the flow of lacrimal fluid?
|
relaxation draws fluid from gland into lake; contraction forces fluid from lacrimal sac into the nasolacrimal duct
|
|
What artery provide the major blood supply for the eye?
Where does it come from and what are its branches? |
ophthalmic a., comes from the internal carotid a.; gives off orbital branches and occular branches
|
|
The orbital branches of the ophthalmic artery provide which areas?
|
lacrimal, supraorbital, anterior/posterior ethmoidal, muscular, supratrochlear, dorsal nasal
|
|
Occlusion of the central artery of the retina results in what?
|
blindness
|
|
The ocular branches of the ophthalmic artery provide which areas?
|
long and short posterior ciliary, anterior ciliary, central artery of the retina
|
|
What are the veins that receive blood from the eye and orbit?
|
superior and inferior ophthalmic v, angular v.
|
|
When the ophthalmic veins unite, what do they drain into?
|
cavernous sinus or pterygoid plexus of veins
|
|
How can an infection spread from the eye orbit into the cranial cavity?
|
via venous drainage pathways
|
|
What is the common tendinous ring and what does it provide for?
|
CT cuff that surrounds the optic canal and part of hte superior oribital fissure - provides origin for the 4 rectus muscles
|
|
What is the name for the connective sheath around the eye that ends at cornea and blends with CT sheaths of inserting extraocular muscles?
|
bulbar sheath (fascia bulb)
|
|
What is formed from the fascia of the extraocular muscles?
|
medial and lateral cheek ligaments and suspensory ligament of the eye
|
|
What are the innervations for the 6 extraocular skeletal muscles?
|
SO4LR6AO3
|
|
What are the four type of movement called in the horizontal and vertical axes of the eye?
|
Adduction, abduction, depression, elevation
|
|
Where is the common tendinous ring positioned in relation to the axis of the eye?
|
it lies medially
|
|
Which muscles cause abduction and adduction of the eyeball, respectively?
|
Lateral rectus (VI)
medial rectus (III) |
|
What is the action of the superior rectus muscle of the eye?
|
elevates the eye and pulls it medially, up and in
|
|
What is the action of the inferior rectus muscle of the eye?
|
depresses the eye and pulls it medually, down and in
|
|
What is path that the superior oblique muscle makes from origin to insertion and what is its action?
|
sphenoid bone --> medial orbit roof --> tendon passes through trochlea --> crosses eye post-lat deep to the superior rectus and inserts on the superior posterior lateral eye, action: down and out
|
|
What is the major muscle that provides intorsion of the eye?
|
superior oblique
|
|
What is path that the inferior oblique muscle makes from origin to insertion and what is its action?
|
anterior medial orbit floor --> crosses eye posteriolateral and deep to the inferior rectus --> inserts on inferior posterior lateral eye, action: up and out
|
|
Which muscles work together to cause elevation, depression, adduction and abduction, respectively?
|
elevation: IO, SR
depression: SO, IR adduction: SR, MR, IR abduction: IO, LR, SO |
|
Which muscles work together to cause intorsion and extorsion, respectively?
|
intorsion: SO, SR
extorion: IO, IR |
|
What is the soft tissue overlying the calvaria called?
|
scalp
|
|
What is the name of the upper bony part of the skull?
|
calvaria
|
|
By what age have the fontanelles fused completely?
|
2
|
|
What type of joint link the flat bones of the skull?
|
synarthroses (sutures)
|
|
What is the clinical significance of fontanelles?
|
they are used to access CSF and venouns blood (either to draw some off or measure pressure)
|
|
What is the spongy core of the flat bones called?
|
dipole
|
|
Flat bones are formed from what structure and what is the clinical significance?
|
CT (membranous bone formation)
periosteum is non-osteogenic |
|
What will happen when, after removal of a large piece of bone from the skull, it is not replaced by a prosthetic device?
|
scarring of the bone tissue will compress the brain and cause epilespy
|
|
What forms the outer dural layer of the meninges?
|
periosteum
|
|
How many true spaces are found in the meninges and what is contained within?
|
1 - subarachnoid, CSF
|
|
What are the layers of the meninges in the calvaria?
|
2 dura, 1 arachnoid, 1 pia
|
|
What two true spaces can be created due to pathology in the calvaria?
|
dural venous sinuses: vascular spaces and denticulate ligaments-like infolding (created either b/w dural layers or underneath inner dural layer)
|
|
What are the 5 layers that comprise the scalp?
|
S: skin
C: CT A: aponeursis L: loose CT P: periosteum |
|
Which layers of the scalp are fused?
|
The first three: skin, CT, aponeurosis
|
|
What is an aponeurois?
|
broad, flat, tendon
|
|
Which layer of the scalp is most likely to tear during trauma?
|
loose CT layer (4)
|
|
What are the two muscles that connect to the aponeurosis of the scalp connected to?
|
occipitalis m. to occipital bone and frontalis m. to skin
|
|
Where are the named neurovascular structures of the scalp located?
|
in the CT layer [2]
|
|
How are the arteries and nerves of the scalp distributed?
|
the named structures in layer 2 give off branches to all of the other layers including the skull
|
|
What are the arterial branches of the scalp called that supply the underlying bone?
|
nutrient branches
|
|
What differentiates the veins in the scalp from the arteries?
|
the veins drain only the 5 layers of the SCALP not the bone
|
|
What are the veins called that drain the skull?
|
diploic veins
|
|
What are the veins called that connect the extra- and intracranial cavities and how do they function?
|
emissary veins - they are low pressure and have no valves (respond to gravity, posture)
|
|
What is the clinical significance of the emissary veins?
|
important in the spread of infections and cancer
|
|
How can a scalp infection (occuring in layer 4) spread?
|
it can enter the eyelids or the bridge of the nose b/c the frontalis m. inserts into the skin. It can NOT spread posteroily b/c the belly of the occipitalis m. is in the way, and it can NOT spread laterally due to the temporalis m.
|
|
What is the clinical significance of the ducts of sebaceous glands associated with hair follicles in the scalp?
|
they can become obstructed, resulting in retention of secretions and the formation of sebaceous cysts, which are prone to infection
|
|
What results from pain due to laceration of the scalp?
|
The occipitalis and frontalis muscles contract creating gaping wounds that interfere with the action of platelets, causing the person to bleed to death
|
|
What pathology can result from hair transplants?
|
Hairs transplanted into hair follicles can obstruct the sebaceous glands causing infection. From there the infection can spread into layer 4, subsequently infecting the upper eyelids and the bridge of the nose
|
|
What is the pericranium (layer 5 of the scalp) continuous with?
|
endocranium (outer dura), continuous through every suture and foramen
|
|
What is the endocranium fused with in four places?
|
inner dura
|
|
Where are the dural venous sinuses located?
|
in the gaps b/w the inner and outer dura
|
|
What are the two specialization of the inner dura and what do they do?
|
vascular spaces and dural reflection folds - anchor dura at the expense of the brain (preventing inertial brain movement) and divide the cranial cavity into compartments
|
|
What does the horizontal fold of the inner dura separate?
|
cerebrum and cerebellum
|
|
Where does the brain stem join the spinal cord?
|
at the foramen magnum
|
|
Where is the gray matter of the CNS located and why?
|
on the outside of the white matter, in order to pack in as many neurons as possible in the convolutions of the brain
|
|
What is CSF analogous to and what other purpose does it serve?
|
lymphatics, and also acts as a shock absorber
|
|
Where and how is the CSF produced?
|
choroid plexus covering all ventricles in an ATP dependent proces
|
|
How does the CSF leave the ventricles?
|
through three foramina in the roof of the fourth ventricle: 2 foramina of Luschka and 1 foramen of Magendie
|
|
How does CSF fluid leave the subarachnoid space?
|
through arachnoid granulations, which are protrusions of arachnoid through the dura into the venous sinuses, the is NOT an ATP-dependent process
|
|
At any given time, how much of the CSF is circulating through the ventricles, central canal, and subarachnoid space?
|
150 mL
|
|
What does a CSF outflow blockage lead to and why?
|
hydrocephalus (increased intracranial pressure), CSF production is ATP dependent and will not decrease whereas CSF outflow is blocked
|
|
What are three causes of hydrocephalus and which are most common?
|
common: blockage of CSF circulatoin, blockage of CSF diffusion into venous sinuses, uncommon: increased CSF production
|
|
Where are venous sinuses formed?
|
where inner and outter dura seperate or dura seperates from itself
|
|
What does venous blood from the dural venous sinuses drain into?
|
internal vertebral plexus (in epidural space) and internal jugular vein - important in the spead of cancer
|
|
What are the natural fracture planes of the skull and what lies within them?
|
the grooves (not the sutures), contain meningeal arteries
|
|
What are intracranial headaches caused by?
|
meningeal nerves, CN V and ventral rami of cervical spinal nerves C2 and C3 (brain itself has no receptors for pain, tepm, touch, and pressure)
|
|
What is the main cause of a cephalohematoma?
|
damage to the nutrient arteries
|
|
What structures can be responsible for causing an EPIDURAL hematoma?
|
most likely: meningeal a., ICA within the carotid canal
least likely: dural venous sinuses, diploic vv. |
|
What structures can be responsible for causing an SUBDURAL hematoma?
|
cerebral/cerebellar veins, veins of the brainstem
|
|
What structures can be responsible for causing an SUBARACHNOID hematoma (=CVA: cerebral vascular accident)?
|
internal carotid a.,vertebral a., basilar a.; cerebral and cerbellar vessels, vessels of the brainstem, CVA can also be caused by occlusive disease
|
|
What are the three types of intracranial hematomas?
|
epidural, subdural, subarachnoid (CVA)
|
|
What is the most predominant cause of a CVA?
|
occlusion of arteries = 85%
rupture of arteries = 15% |
|
In neck anatomy, what makes up the posterior triangle?
|
SCM, trapezius, clavicle
|
|
What is the condensation of prevertebral and pretracheal fascia called that extends from the base of cranium to the root of the neck?
|
carotid sheath
|
|
What structures are located within the carotid sheath?
|
vagus n, ansa cervicalis,CCA, ICA, IJV
|
|
What structures are associated with the carotid sheath (not located within)?
|
deep cervical lymph nodes, carotid sinus and nerve, periarterial sympathetic plexus
|
|
In neck anatomy, what makes up the anterior triangle?
|
SCM, neck midline, inferior border of the mandible
|
|
What lymph nodes are considered level I nodes and from what location would a tumor spread to these nodes?
|
submental, submandibular - oral cavity
|
|
What lymph nodes are considered level II, III, and IV nodes, respectively, and from what location would a tumor spread to these nodes?
|
upper, middle, and lower jugular: level II and III from oral cavity, oropharynx, nasopharynx, hypopharynxlevel IV from hypopharynx, larynx, thyroid, and cervical esophagus
|
|
During what period of development does most of the face and palate develop?
|
during the 2nd month of prenatal life
|
|
What are the top three causes of human congenital abnormalities?
|
1. unknown etiology
2. multifactorial inheritance 3. environmental agents |
|
What are two examples of differential growth?
|
1. spinal cord stops growing while the vertebral canal continues to grow
2. human brain grows faster than that of a fish pushing our eyes closer together |
|
What are two types of union and what are their characteristics?
|
1.merging: two bumps are united by mesenchymal growth (not a complex process)
2. fusion: epithelia if two seperate structures comes together and dissolve to form a new structure |
|
What are the names of the 5 lumps that surround the stomodeum?
|
frontonasal prominence, maxillary prominence (L and R), mandibular prominence (L and R)
|
|
What will form from the frontonasal prominence?
|
forehead, middle of the nose, part of the upper lip, dental arch
|
|
What will form from the mandibular prominence?
|
mandible and other contents of the lower jaw, both sides meet as a dimple in the chin
|
|
What is the stomodeum?
|
primative oral cavity
|
|
What will form from the maxillary prominence?
|
cheeks, parts of the upper lip, maxillary and zygomatic bone, part of the temporal bone
|
|
What is the 2nd pharyngeal arch also known as?
|
hyoid arch
|
|
What are the nasal placodes and nasal pits, respectively?
|
thickenings of epithelium, future nostrils
|
|
What makes up the 1st pharyngeal arch?
|
maxillary and mandibular prominences
|
|
What happens to the nasomedial processes during development?
|
they merge to form the intermaxillary segment which will become the middle of the nose, philtrum of the upper lip, part of the dental arch w/ 4 incisors, primary palate
|
|
What happens to the nasolateral processes during development?
|
will form the sides and wings of the nose
|
|
What are the upper and lower lip/jaw formed by, respectively?
|
upper: both nasomedial processes, and both maxillary processes
lower: mandibular processes |
|
In what sex/race is cleft lip most common vs. a cleft palate?
|
cleft lip: white males
cleft palate: females |
|
What causes a bilateral cleft lip?
|
failure of medial nasal processes to fuse with maxillary swellings
|
|
What are some of the symptoms seen in people with frontonasal dysplasia?
|
eyes further apart, bifid nose
|
|
What is formed when the maxillary process joins the nasolateral process on each side of the nose?
|
nasolacrimal groove, which later becomes the nasolacrimal duct - dilated upper ends becomes the lacrimal sac
|
|
Failure of the maxillary process to join the nasolateral process leads to what rare condition?
|
oblique facial cleft, or oronasal optic cleft
|
|
What will the small bumps between the mandibular arch and the hyoid arch become?
|
ears
|
|
Of the six pharyngeal (branchial) arches, which one dissapears?
|
5th
|
|
What is the general cellular layout of a pharyngeal arch (which cell type occurs where)?
|
core of mesenchyme (mesoderm + neural crest cells); covered on the outside by ectoderm and the inside by endoderm
|
|
Which nerves are derived from the pharyngeal arches?
|
1st: trigeminal(V2/V3)
2nd: facial (VII) 3rd: glossopharyngeal (IX) 4th-6th: vagus (X) |
|
What is the one muscle derived from the 3rd pharyngeal arch?
|
stylopharygeus
|
|
What are pharyngeal clefts and what are pharyngeal pouches?
|
clefts are grooves on the outside of the embryo whereas pouches are grooves on the inside of the mebryo
|
|
What does the first pharyngeal cleft form?
|
external auditory meatus
|
|
What do all pharyngeal clefts (except for the first) form and what can happen to them?
|
form cervical sinus which later disappears - if they dont dissappear it can form a cervical cyst and may cause fistuals
|
|
What does the first pharyngeal pouch form?
|
auditory or eustachian tube, middle ear cavity
|
|
What embryonic cell types is the tympanic membrane composed of?
|
ectoderm and endoderm
|
|
What do the 2nd, 3rd, and 4th pharyngeal pouches form, respectively?
|
2nd: palatine tonsil
3rd: Parathyroid gland (inferior) 4th: parathyroid gland (superior) and ultimobrachial body |
|
What does the ultimobranchial body develop into?
|
calcitonin producing cells in the parathyroid gland (parafollicular cells/clear cells)
|
|
What does the thyroid gland develop from?
|
foramen cecum (located at the jcn b/w the anterior 2/3 and posterior 1/3 of the tongue)
|
|
What are remnants of the thyroid gland called that are left along its developmental path?
|
thyroglossal cysts or abberent thyroid tissue (always close to midline)
|
|
What are complications found with lateral cervical cysts and where would these complications present?
|
lateral cervical fistulas located around the anterior border of the SCM muscle
|
|
What part of the skeleton are formed from the 1st pharyngeal arch?
|
incus, malleous, Meckel's cartilage
|
|
What part of the skeleton are formed from the 2nd pharyngeal arch?
|
stapes, styloid proces, styloid ligament, lesser horn of the hyoid bone
|
|
What part of the skeleton are formed from the 3rd, 4th, and 5th pharyngeal arches, respectively?
|
3rd: body of the hyoid bone, greater horn of the hyoid bone
4th: thyroid cartilage 5th: cricoid cartilage |
|
What can Treacher Collins' syndrome be caused by and what does it lead to?
|
genetic defects, abnormal neural crest cell migration/differentiation, result in a defect of the 1st pharyngeal arch leading to mandibular hypoplasia
|
|
From what processes/prominences is the palate formed and what does each form specifically?
|
maxillary (palatal shelves which form the secondary palate)
nasomedial (primary palate) |
|
What structures must fuse to form 1 oral and 2 nasal cavities?
|
primary palate must join with fused secondary palates; nasal septum grows downwards and fuses
|
|
What would be an example of a minor posterior cleft palate?
|
cleft uvula
|
|
Where does the tongue develop and what does it grow into?
|
develops into the floor of the oral cavity but grows rapidly to expand into the nasal cavity
|
|
What does the anterior 2/3 of the tongue form from?
|
from 1st arch: 2 lateral lingual swellings and the tuberculum impar
|
|
What forms the tongue muscles?
|
occipital somites
|
|
What is ankyloglossia and what causes it?
|
Frenulum extends to tip of tongue (also known as tongue-tie) - caused by a lack of cell degeneration under the tongue during development
|
|
Incomplete union of what two structures causes a bifid tongue?
|
lateral lingual swellings
|
|
What bones mark the junction called the pterion and what is its clinical significance?
|
parietal, temporal, frontal, sphenoid - weakest part of the skull; middle meningeal a. runs beneath, Fx here can cause an epidural hematoma
|
|
What boundary demarcates the infratemporal fossa and what is located within?
|
below the zygomatic arch and deep to the ramus of the mandible, contains derivatives from the first pharyngeal arch
|
|
What structures travel through the mental foramen?
|
terminal branches of the inferior alveolar nerves and vessels (a.k.a mental nerves and vessels)
|
|
What muscle forms the floor of the oral cavity and what is it attached to?
|
mylohyoid muscle attached to the mylohyoid line
|
|
What type of joint is the TMJ and what is it lined with?
|
synovial joint lined with dense fibrous tissue w/ chondrocytes (fibrocartilage)
|
|
What does the articular disc divide the TMJ into and what does each part do?
|
upper space: sliding, transition
lower space: hinge action, rotation |
|
What is the most important stabilizing ligament of the TMJ?
|
lateral collateral ligament
|
|
What are the tubercles called that lie anteriorly and posteriorly to the TMJ?
|
anterior: articular tubercle
posteior: postglenoid tubercle |
|
A blow to the mandible can fracture what structures?
|
condyle driven superiorly: middle cranial fossa
condyle driven posteriorly: boney ear canal |
|
What can cause the TMJ to dislocate anteriorly and what normally prevents this from happening?
|
yawning, laughing, taking a large bite,dental work - articular tubercle prevents anterior dislocation
|
|
What structures of the TMJ prevent posterior dislocation?
|
postglenoid tubercle and lateral ligament
|
|
What are the supporting structures of the TMJ?
|
lateral: lateral ligament
medial: sphenomandibular ligament posterior: stylomandibular lig. anteriorly: tendon of the lateral pterygoid m. |
|
Which ligament of the TMJ attaches to the mandibular lingula?
|
sphenomandibular lig
|
|
Branches of what nerves provide innervation for the TMJ?
|
mainly auricotemporal (V3), aso branches from masseteric n. and posterior deep temporal n. (both V3)
|
|
What vessels provide the blood supply to the TMJ?
|
Branches of ascending pharyngeal and superficial temporal aa. (directly from external carotid a.); auricular and anterior tympanic aa. (from maxillary a.)
|
|
What are the 4 muscles of mastication and what innervates them?
|
Temporalis, masseter, lateral pterygoid, medial pterygoid - innervated by branches of V3
|
|
What muscles are used in elevation of the jaw?
|
temporalis, masseter, medial pterygoid
|
|
What muscles are used in protrusion of the jaw?
|
lateral pterygoid (prime mover), masseter, medial pterygoid
|
|
What muscles are used in depression of the jaw?
|
lateral pterygoid, infra/surpahyoid - gravity is prime mover
|
|
When damage to V3 leads to paralysis of the masticatory mm., how will the mandible deviate?
|
towards the same side as lesion, ipsilateral
|
|
Regarding proprioception, where are the nerve cell bodies for CN XI located (SCM & trapezius)?
|
Dorsal root ganglion of C3-4
|
|
Insertion of a tube for chronic ear infection may injure what nerve?
|
chorda tympani (ant. 2/3 of tongue, taste)
|
|
Where is a mandibular nerve block performed and what branches are anesthetized?
|
Through mandibular notch - anesthetizes branches of V3: auriculotemporal, inferior alveolar, lingual, buccal
|
|
Where is an inferior alveolar nerve block performed and what branches are anesthetized?
|
Around the mandibular foramen - anesthetizes all mandibular teeth, skin and mucosa of lower lip, labial alveolar mucosa and gums, skin of chin
|
|
What muscle divides the maxillary artery into three parts and what are they named?
|
Lateral pterygoid m. divides maxillary a. into mandibular, pterygoid, and pterygopalatine part
|
|
The mandibular part of the maxillary a. gives rise to which branches?
|
deep auricular, anterior tympanic, middle meningeal, accessory meningeal, inferior alveolar aa.
|
|
The pterygoid part of the maxillary a. gives rise to which branches?
|
Muscular branches: deep temporal, masseteric, pterygoid, buccal aa.
|
|
Infection from what area of the superficial face can spread to the cavernous sinus?
|
midface, nose, upper lip - drained by facial v. --> deep facial v. -->pterygoid plexus --> inferior ophthalmic v. --> cavernous sinus
|
|
What functions do the fascia of the cervical region provide?
|
compartmentalization, slipperiness, conduit for food and blood
|
|
What layers is the deep fascia of the cervical region divided into?
|
investing layer
pretracheal layer prevertebral layer |
|
What is space located posteriorly to the pharynx and what is it bordered by laterally?
|
retropharyngeal space boardered by the carotid sheath
|
|
Where can an infection of the retropharyngeal space spread to?
|
first it can create a buldge in the oropharynx; then it can spread via the esophagus to the posterior mediastinum
|
|
What does the investing fascia surround?
|
splits to enclose the trapezius, SCM, submandibular gland; forms fibrous capsule of the parotid gland
|
|
What does the pretracheal fascia surround?
|
encloses the thyroid/parathyroid glands, trachea/larynx, esophagus/pharynx
|
|
What is the pretracheal fascia continuous with posteriorly and superiorly?
|
buccopharyngeal fascia
|
|
Where does the prevertrebral fascia run and what does it form?
|
from cranium to T3; blends with the anterior longitudinal ligament; froms axillary sheath
|
|
What structures are contained within the carotid sheath?
|
IJV, CCA/ICA, vagus nerve; also lymphnodes, nerve to the carotid sinus, and symp nerve fibers
|
|
What layers of the fascia is the carotid sheath composed of?
|
investing fascia, pretracheal fascia, prevertebral fascia
|
|
Where can a pretracheal infection spread to?
|
superior and anterior mediastinum
|
|
What structure divides the posterior triangle of the neck?
|
inferior belly of the omohyoid divides the posterior triangle into the occipital and supraclavicular (subclavian) triangles
|
|
What is the most damaged structure during surgery in the posterior triangle and what clinical signs will be associated with this?
|
CN XI - drooping shoulder, inability to elevate and retract the shoulder, difficulty raising the arm above the horizontal
|
|
What can a fibrous tissue tumor in the SCM lead to?
|
torticollis - tilt the head towards the affected side
|
|
What happens to the clavicle's position after midline fracture?
|
medial end goes up (SCM), lateral end goes down (gravity)
|
|
Where do the cutaneous nerves of the neck exit?
|
erb's point, posterior border of the SCM
|
|
What cutaneous nerve runs up along the posterior border of the SCM?
|
occipital n
|
|
What cutaneous nerve runs obliquely across the anterior SCM to the ear?
|
great auricular n.
|
|
What is the space called between the anterior and middle scalene mm. and what runs in it?
|
interscalene triangle, brachial plexus
|
|
What structures lie anterior to the anterior scalene m.?
|
subclavian v., phrenic n., suprascapular a., transverse cerivcal a.
|
|
What vessel runs with CN XI?
|
transverse cervial a.
|
|
What pathology can affect the omoclavicular triangle and root of the neck?
|
referred pain, too narrow gap, extra slip of muscle, cervical rib, compressed structures
|
|
What are some of the causes of engorged neck veins?
|
heart failure, narrowed pulmonary valve, resistance in pulmonary circulation, lunger cancer/enlarged lymph nodes compressing the SVC
|
|
What two structures divide the anterior triangle and what divisions do they form?
|
digastric m, superior omohyoid - forms submandibular triangle
carotid triange, muscular triange, submental trianle |
|
After a double fracture of the mandible at the mental foramina, which way will the central piece of mandible be pulled and why?
|
inferiorly by the digastric mm
|
|
What muscle forms the floor of the submandibular and submental triangles?
|
mylohyoid
|
|
What muscle raises the floor of the mouth?
|
mylohyoid
|
|
At what cervical vertebrae are the following structures located: hyoid bone, carotid bifurcation, cricoid cartilage?
|
C3
C4 C6 |
|
What muscles can be affected by a nail piercing through the midline of the submental triangle?
|
mylohyoid
|
|
What are the suprahyoid muscles and what innervates each?
|
mylohyoid, anterior diagastric (V3)
stylohyoid, posterior diagastric (VII) geniohyoid (C1) |
|
infrahyoid muscles and what innervates each?
|
omohyoid, sternohyoid, sternothyroid (ansa cervicalis), thyrohyoid (C1)
|
|
Branches of C1 that travel with CN XII provide innervation to what structures?
|
geniohyoid and thyrohyoid
|
|
What is the difference between a tracheostomy and a tracheotomy?
|
in a tracheostomy a piece of cartilage is removed in addition to the incision already required
|
|
What are the structures at risk during a tracheostomy?
|
recurrent laryngeal nerve
|
|
Which nerve goes to the cricothyroid and inferior constrictor m.?
|
external laryngeal n.
|
|
What nerve does the superior thyroid artery run with?
|
external laryngeal n/
|
|
What nerve does the superior laryngeal artery run with?
|
internal laryngeal n.
|
|
What nerve runs with the inferior thyroid artery?
|
reccurrent laryngeal n.
|
|
What are thyroglossal cysts/fistulas always close to?
|
midline of the neck (usually around the hyoid region)
|
|
What two arteries supply the thyroid gland?
|
superior and inferior thyroid arteries
|
|
What are two exceptions in the head/neck to the concept of neurovascular bundles?
|
facial artery and lingual nerve
|
|
What organs do not have anastomosing networks of arteries and are thus susceptible to disease?
|
brain (except circle of Willis), heart, liver, kidney, eye
|
|
Branches of what artery supply most of the neck?
|
ECA
|
|
Besides venous and lymphatic routes, what way can cancer also metastasize?
|
via fascial planes (fascia of the retropharyngeal space)
|
|
What structures border the carotid triangle?
|
SCM, posterior belly of the digastric, superior part of the omohyoid
|
|
What pathology does a bruit heard in the carotid triangle suggest?
|
a plaque
|
|
In what three locations of the head/neck region can a pulse be palpated?
|
facial a.
carotid triangle superficial temporal a. |
|
Which artery has a coiled path and why is this important?
|
so it doesnt kink when the mandible is depressed
|
|
Branches of which arteries form collateral circulation in the scalp?
|
occipital a., posterior auricular a., superficial temporal a., opthalmic a.
|
|
What does the angular a. anastomose with at the angle of the eye?
|
ophthalmic a.
|
|
What are the four arteries that anastomose on the superficial face?
|
facial a., superficial temporal a. (transverse facial a.), maxillary a. (buccal, mental, infraorbital), opthalmic a
|
|
What artery supplies the tongue?
|
lingual a.
|
|
What does the descending pharyngeal a. branch off of?
|
maxillary a.
|
|
What nerve runs anterior to the anterior scalene m.?
|
phrenic n.
|
|
Which arteries create the collateral circulation for the deep neck (vertebral)?
|
vertebral a., occipital a. (descening), ascending cervical a. (from thyrocervical trunk), deep cerivcal a. (from costocervical trunk)
|
|
What does the deep cervical a. anastomose with superiorly?
|
occipital a.
|
|
Which vessels create the collateral circulation supplying the area around the thyroid?
|
superior thyroid a.
inferior thyroid a. ima thyroid a. |
|
Which four arteries create the collateral circulation of the deep face?
|
facial a., lingual a., opthalmic a. (anterior ethmoid), maxillary a.
|
|
Which four arteries create the collateral circulaton for the pharynx/tonsillar bed?
|
facial a., lingual a.,ascending pharyngeal a., maxillary a. (pharyngeal)
|
|
What do the superficial temporal vein, posterior auricular veins, and pterygoid plexus drain into?
|
retromandibular v.
|
|
What does the facial vein normally drain into?
|
IJV
|
|
What are the two exceptions to the rule that only the right-upper portion of the body drains lymph into the right lymphatic duct?
|
the entire liver capsule and lower left lung lobe also drain into the right lymphatic duct
|
|
What are the sentinel nodes named in the head/neck lymphatic drainage system?
|
jugulo-digastric, jugulo-omohyoid, supraclavicular nodes
|
|
What do the lymphatics of Waldeyer's tonsilar ring drain into?
|
jugulo-digastric
|
|
What artery supplies the superficial AND deep face?
|
facial a.
|
|
What nodes do the submandibular lymph nodes drain into?
|
jugulo-omohyoid
|
|
What lymph nodes do the entire visceral tube and thyroid gland drain into?
|
'spiral' deep cerivcal lymph nodes (then right side to right side lymphatic duct/left side to left thoracic duct)
|
|
What sentinel node do the lymphatics of the superficial face drain into?
|
jugulo-digastric
|
|
What do the lymphatics posterior 1/3 of the tongue drain into?
|
jugulo-digastric node (anterior 2/3 goes to jugulo-omohyoid via submandibular nodes)
|
|
What is the primary cause of intracranial hemorrhage?
|
fracture to the skull
|
|
Which layer of the meninges has no pain receptors?
|
pia mater
|
|
Dizziness is a symptom of compression of which cranial nerve?
|
CN VIII
|
|
Which vascular bundle is located in the lateral fissure?
|
middle cerebral a. and v.
|
|
Which bones or part of which bones make up the calvaria?
|
frontal, parietal, occipital bones, squamous part of the temporal bone, greater wing of the sphenoid
|
|
What is the location called where a lamboidal suture meets with the squamosal suture?
|
asterion
|
|
What is the location where the coronal and sagittal sutures meet?
|
bregma
|
|
In an epidural hematoma, caused by a fracture of the pterion, what structures other than the middle meningeal artery can contribute to the bleed?
|
middle meningeal v., sphenoparietal dural venous sinus
|
|
Activation of branches of what nerve provoke intracranial headache?
|
meningeal branches of CN V (anterior and middle meningeal nerves) and branches of the upper cervical ventral rami (posterior meningeal nerve)
|
|
What are two causes of papilledema?
|
compression of the optic nerve from outside by CSF; central retinal aa. and vv. are located with in the optic nerves and can put pressure on the nerve from within
|
|
What can happen with a fracture along the floor of the middle cranial fossa?
|
fracture can go across from the inner and middle ear, can include the carotid canal and jugular foramen causing bleeding from the inner ear and nose
|
|
What innervates the inside (endoderm) and outside (ectoderm) of the foregut, respectively?
|
visceral nerves, somatic nerves
|
|
Is the oral cavity considered to be part of the inside or outside portion of the foregut?
|
outside
|
|
What is the posterior boundary of the oral cavity?
|
the area where the soft palate drops down, above the seperation of the tongue
|
|
What are the vertical boundaries of the oropharynx?
|
soft palate (superiorly)
epiglottis (inferiorly) |
|
Through what vertebral levels does the laryngopharynx extend?
|
C3- C6
|
|
What two structures is the pharynx attached to (superiorly and inferiorly)?
|
base of the skull and the esophagus at C6
|
|
What three openings does the pharynx possess?
|
openings into the nasal cavity, oral cavity, and larynx
|
|
Which two nerves supply the pharynx and how is the muscular nerve supply divided?
|
CN IX (stylopharyngeus) and X (all others)
|
|
In the pharynx, which muscle layer is found on the inside?
|
longitudinal (outside is circular)
|
|
What is the epithelium found in the pharynx?
|
stratified squamous, non-keritinized
|
|
What is the external fibrous layer of the pharynx also known as?
|
buccopharyngeal fascia
|
|
What is the fascia called that connects the superior constrictor muscle to the base of the skull?
|
pharyngobasilar fascia
|
|
What structures are located between the superior and middle constrictor mm.?
|
stylopharyngeus, CN IX
|
|
What is the lower part of the inferior constrictor m. sometimes called and what is its function?
|
cricopharyngeus m. -acts a sphincter of the upper esophagus
|
|
Where does the middle constrictor m. have its major attachment?
|
hyoid bone
|
|
What do the anterior and posterior borders of the pterygomandibular raphe give attachment to, respectively?
|
anterior: buccinator
posterior: superior constrictor m. |
|
What are the three longitudinal muscles located inside the pharynx?
|
salpingopharyngeus
palatopharyngeus stylopharygeus |
|
Where does the salpingopharyngeus m. arise from?
|
eustachian tube
|
|
What is the common point of attachment of the stylopharyngeus and palatopharyngeus mm.?
|
thyroid cartilage
|
|
What is the function of the stylopharyngeus m.?
|
elevation of the pharynx
|
|
What is the external fibrous layer of the pharynx also known as?
|
buccopharyngeal fascia
|
|
What is the fascia called that connects the superior constrictor muscle to the base of the skull?
|
pharyngobasilar fascia
|
|
What structures are located between the superior and middle constrictor mm.?
|
stylopharyngeus, CN IX
|
|
What is the lower part of the inferior constrictor m. sometimes called and what is its function?
|
cricopharyngeus m. -acts a sphincter of the upper esophagus
|
|
Where does the middle constrictor m. have its major attachment?
|
hyoid bone
|
|
What do the anterior and posterior borders of the pterygomandibular raphe give attachment to, respectively?
|
anterior: buccinator
posterior: superior constrictor m. |
|
What are the three longitudinal muscles located inside the pharynx?
|
salpingopharyngeus
palatopharyngeus stylopharygeus |
|
Where does the salpingopharyngeus m. arise from?
|
eustachian tube
|
|
What is the common point of attachment of the stylopharyngeus and palatopharyngeus mm.?
|
thyroid cartilage
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What is the function of the stylopharyngeus m.?
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elevation of the pharynx
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What are the three paired cartilages of the larynx?
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arytenoid, corniculate, cuneiform
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What are the three UNpaired cartilages of the larynx?
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Epiglottic, thyroid, cricoid cartilages
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Which structure determines the minimal diameter of the larynx?
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Cricoid cartilage
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Which arteries supply the larynx?
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Superior and inferior laryngeal aa. (from superior and inferior thyroid aa.)
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Which nerves innervate the larynx?
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Superior and inferior laryngeal nn. (from CN X)
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What are the functions of the larynx?
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Respiration, phonation, cough mechanism, control valve for respiration (epiglottis)
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Which arteries supply the pharynx?
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Ascending pharyngeal (from external carotid); ascending palatine and tonsillar (from facial); pharyngeal and descending palatine (from maxillary)
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Which structures lie anterior and posterior to the palatine tonsil in the palatine fossa?
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Anteriorly: palatoglossal fold/arch and muscle; posteriorly: palatopharyngeal fold/arch and muscle
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What is the function of the stylopharyngeus m.?
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Elevation of the pharynx
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What is the lateral process of the arytenoid cartilage called?
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muscular process
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What is the anterior process of the arytenoid cartilage called and what is attached to it?
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vocal process and vocal folds attach here
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What is located between the cricoid and arytenoid cartilages and what does it allow for?
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a synovial joint, allows for rotation and gliding, medially/laterally
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What is located between the inferior horn of thyroid cartilage and cricoid cartilage and what does it allow for?
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A synovial joint - allows rostrocaudal tipping of the thyroid cartilage
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What are the extrinsic muscles of the larynx and what is their function?
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suprahyoid (and stylopharyngeus) and infrahyoid mm (adductor along with transverse arytenoids)
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What to muscles attach to the muscular process of the arytenoid cartilages?
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Posterior cricoarytenoid mm. (abductor) and lateral cricoarytenoid mm. (adductor - along with transverse arytenoids)
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What is the function of the cricothyroid m.?
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it tips the thyroid cartilage forward creating tension on the vocal ligaments (tensors)
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What are the two major functions of the intrinsic mm. of the larynx?
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change length (tension) of the vocal cords to manage size and shape of rima glottis
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Which muscles are relaxers of the vocal folds?
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thyroarytenoid mm, vocalis mm
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What provides innervation of the cricothyroid mm.?
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external laryngeal branch of CN X (all other intrinsic mm are innervated by recurrent laryngeal nerve)
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What does the internal laryngeal nerve penetrate and what does it travel with?
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thyrohyoid membrane - superior laryngeal a.
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Which nerve is associated with the cough reflex?
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internal laryngeal n
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What is the main innervation for the oral and nasal cavities, and what is one key exception?
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CN X everything but the tongue
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What bone are the middle and superior conchae part of?
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ethmoid bone
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What muscle forms the floor of the oral cavity?
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mylohyoid
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What is the name of the space that lies between the cheek and gums?
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vestibule
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What do the intrinsic and extrinsic muscles of the tongue do, respectively?
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intrinsic: shape the tongue
extrinsic: move the tongue as a whole |
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What artery lies medial to the hyoglossus muscle?
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lingual a.
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What structures are located superior to mylohyoid m. but lateral to hyoglossus m.?
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sublingual gland, lingual n., CN XII
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Where in the oral cavity does the parotid duct empty?
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adjacent to the upper 2nd molar
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What is the major source of lubrication for the oral cavity?
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accesory salivary glands
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What nerves supply the hard and soft palate, respectively?
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greater palatin, lesser palatine (from V2 - through the PP ganglion)
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How many primary and secondary teeth do humans have and how are they divided?
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primary (baby): 20 (212); secondary (permanent): 32 (2123, 2 incisions, 1 canine, 2 premolars, 3 molars)
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What structures pass through the incisive canal?
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nasopalatine nerve and branches from the descending palatine a.
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What marks the site where the thyroid gland devaginated?
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foramen caecum on the posterior aspect of the tongue
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What innervates the circumvalate papillae?
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CN IX (also the post. 1/3 of the tongue)
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What is the major artery that supplies the tongue?
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lingual a.
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What cranial nerves provide taste sensation for the posterior 1/3 of the tongue?
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CN IX, X (both also provide GVA to post. 1/3)
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What are the bones that form the nasal septum?
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vomer and ethmoid
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What are the major sources of blood supply to the nasal cavity?
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sphenopalatine a., ethmoidal aa., facial a (in the vestibule)
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What nerve innervates the anterior portion of the nasal septum?
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anterior ethmoidal from the nasociliary (V1)
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In what area does most of the drainage of the nasal cavity occur?
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middle meatus
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What area of the nasal cavity does the nasolacrimal duct drain into (i.e. tears)?
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inferior meatus
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Which cranial nerves are involved in the special senses?
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CN I and II
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Which cranial nerves originate from and exit the brain stem?
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III - X, XII
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What is the name of the functional component of cranial nerves that innervate skeletal muscles derived from pharyngeal (branchial, visceral) arches?
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Special Visceral Efferent (SVE)
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The pharyngeal arches contribute to which cranial nerves?
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V, VII, IX, X
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Lesions to motor branches of the cranial nerves will result in what?
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ipsilateral complete or partial paralysis, depending on the extent of the lesion
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Where are the motor nuclei of both motor to skeletal muscle and parasympathetic motor to viscera located?
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in the brain stem
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Where do the preganglionic axons of the GVE component of cranial nerves synapse?
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in parasympathetic motor ganglia
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What is the name for the parasympathetic motor ganglia associated with CN III and where is it located?
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ciliary ganglion, located on the lateral side of CN II
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What are the names for the two parasympathetic motor ganglia associated with CN VII and where are they located?
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pterygopalatine (or sphenopalatine) ganglia - suspended from the maxillary division of CN V; submandibular ganglion - on the surface of the hyoglossus muscle
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What is the name for the parasympathetic motor ganglia associated with CN IX and where is it located?
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otic ganglia - suspends on the medial side of the mandibular division of CN V
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What is the name for the parasympathetic motor ganglia associated with CN X and where is it located?
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intramural ganglion - on the walls of the innervated organ
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Where are the sensory ganglia of cranial nerves typically located?
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located along the CN close to their origin (inside the cranial cavity or just as it exits the cranial cavity)
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What are the names of the sensory ganglia associated with CN V, VII, IX & X, respectively?
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V: semilunar (trigeminal)
VII: geniculate IX: superior and inferior glossopharyngeal X: superior and inferior vagal |
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From what location do GVA fibers begin sending signals to the cranial nerves?
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from the pharynx on down (includes chemoreceptors, barorecptors, distension, pain)
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What locations have GSA fibers that send signals to the cranial nerves?
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skin, conjunctive, meninges, mucous memb of the oral cavity and nasal cavity (include touch, pain, thermal,pressure, vibration, proprioception)
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Which senses send signals using SSA fibers and which using SVA fibers?
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SSA: vision, auditory, vestibular
SVA: taste, olfaction |
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The first order neuron (primary neuron) is what type of neuron?
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pseudounipolar neuron located in the cranial sensory ganglion
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What does the axon of the first order neuron synapse on as it travels into the brain stem?
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second order sensory neurons in the brain sensory nuclei (forming ganglia)
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What are the names for the two parasympathetic motor ganglia associated with CN VII and where are they located?
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pterygopalatine (or sphenopalatine) ganglia - suspended from the maxillary division of CN V; submandibular ganglion - on the surface of the hyoglossus muscle
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What is the name for the parasympathetic motor ganglia associated with CN IX and where is it located?
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otic ganglia - suspends on the medial side of the mandibular division of CN V
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What is the name for the parasympathetic motor ganglia associated with CN X and where is it located?
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intramural ganglion - on the walls of the innervated organ
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Where are the sensory ganglia of cranial nerves typically located?
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located along the CN close to their origin (inside the cranial cavity or just as it exits the cranial cavity)
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What are the names of the sensory ganglia associated with CN V, VII, IX & X, respectively?
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V: semilunar (trigeminal)
VII: geniculate IX: superior and inferior glossopharyngeal X: superior and inferior vagal |
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From what location do GVA fibers begin sending signals to the cranial nerves?
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from the pharynx on down (includes chemoreceptors, barorecptors, distension, pain)
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What locations have GSA fibers that send signals to the cranial nerves?
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skin, conjunctive, meninges, mucous memb of the oral cavity and nasal cavity (include touch, pain, thermal,pressure, vibration, proprioception)
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Which senses send signals using SSA fibers and which using SVA fibers?
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SSA: vision, auditory, vestibular
SVA: taste, olfaction |
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The first order neuron (primary neuron) is what type of neuron?
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pseudounipolar neuron located in the cranial sensory ganglion
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What does the axon of the first order neuron synapse on as it travels into the brain stem?
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second order sensory neurons in the brain sensory nuclei (forming ganglia)
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How does the axon of the second order neuron travel and what does it synapse on?
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Axons usually decussate (cross midline) and synapse on third order neurons in the thalamus
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What pathology can cause damage to CN I?
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CNS disease (demyelinating), tumors on floor of anterior cranial fossae, anteroposterior skull fracture parallel to sagittal suture
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What type of trauma can shear off axons of CN I as they pass through the cribiform plate and what is a subsequent effect of the trauma?
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Anteroposterior skull fractures parallel to sagittal suture - can cause leaking of CSF into nasal cavity (possible route for infection to CNS)
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Where are the secondary neurons of CN I found?
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In the olfactory bulb
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What is anosmia?
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Loss of olfaction
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What do the basal axons of the olfactory nerve (CN I) pierce through after leaving the olfactory bulb?
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Cribiform plate of ethmoid bone
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What do sympathetic postganglionic axons of cranial nerves travel along?
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Blood vessels or in branches of cranial nerves (mostly CN V)
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Parasympathetic postganglionic axons can "hitch-hike" from their ganglion through branches of which cranial nerve?
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CN V
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What does a lesion ABOVE the level of the second order sensory nuclei result in?
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Contralateral symptoms - as opposed to ipsilateral symptoms at or below the level of the second order sensory nuclei
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What are the three layers of the eye?
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outer fibrous layer: sclera/cornea
middle vascular layer: choroid, ciliary body, iris inner retina |
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What are the three layers of the neural retina (from basal to apical)?
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photoreceptor layer: rods/cones
bipolar neurons: primary sensory neurons ganglion cells: secondary sensory nerves |
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Where do the axons of the ganglion cells of the neural retina converge?
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at the optic disc to form the optic nerve
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When considering anatomical relationships, where is the optic chiasm located?
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hypothalamus lies superior to it, pituitary gland lies inferior, internal carotid a. lies lateral
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What is the path that the optic nerve travels after taking its origin from the eye?
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optic canal of orbit --> middle cranial fossa --> optic chiasm --> optic tracts --> thalamus, pretectal area, or superior collicus
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What are the pretectal area and superior colliculus involved in?
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reflex pathways for the optic nerve
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What does the lateral visual field project to in contrast to the medial visual field?
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lateral to nasal (medial) retina; medial to temporal (lateral) retina
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Which axons cross over in the optic chiasma?
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those from the nasal (medial) retina cross over to the opposite side whereas those from the temporal (lateral) retina remain on their respective sides
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Information from the left visual field is carried in which optic tract?
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right optic tract to the right cortex (whereas right visual field goes to the left optic tract)
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What does lesion of the optic nerve result in?
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ipsilateral blindness
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When a pituitary tumor or a lesion affects the mid chiasm, what is the result?
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loss of crossing fibers means loss of lateral visual fields of both eyes ( = bitemporal hemianopsia)
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What results from an aneurism of the internal carotid artery around the optic chiasm?
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loss of fibers from the lateral retina fibers leading to loss of nasal visual field on the same side (= ipsilateral nasal hemianopsia)
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What does a lesion of the optic tract result in?
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loss of lateral retinal axons from the same side and nasal retinal axons from the opposite side result in loss of visual field in opposite side of the lesion (=contralateral homonymous hemianopsia)
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Why is the optic nerve subject to CNS disease?
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it is an extension of the CNS
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What effect will an increase in intracranial pressure have on the optic nerve and what is the mechanism?
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papilledema - since the optic nerve is surrounded by meninges, its subarachnoid space is continuous with the brain subarachnoid and thus will be effected by changes in CSF pressure, this increase will impede venous return from around the optic nerve and cause edema
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How is the integrity of CN II tested?
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by looking at visual activity, visual fields, pupillary and accomadation reflexes
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Where is the ciliary body located and what does it form?
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b/w iris and choroid - forms ring around the eyeball
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What is the name of the circular pigmented structure anterior to ciliary body and what is its central opening?
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iris - pupil
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What are the processes called that extend from the ciliary body and what do they do?
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zonular fibers (suspensory ligaments) - suspend the lens
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What is the shape of the lens at rest?
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flat
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What happens when the ciliary muscles contract and what is the purpose?
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contraction decreases tension on the zonular fibers attached to the lens and it rounds up - accomadation reflex for near vision
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What are the two main muscles in the iris and what fibers are they made up of?
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constrictor pupillae m - circular fibers
dilator pupillae m - radial fibers |
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What muscles of the eye are innervated by the PARAsympathetic branch of CN III (occulomotor n.)?
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ciliary m and constrictor pupillae
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What muscle of the iris is innervated by the sympathetic nerves (superior cervical ganglion)?
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dilator pupillae
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In testing extraocular muscle integrity, how are the MR and LR tested?
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Tracking a finger horizontally
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In testing extraocular muscle integrity, how are the SR and IR tested?
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First, bring axis of eye into alignment with long axis of muscle by tracking a finger laterally (abduct), then track up (SR) or down (IR)
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In testing extraocular muscle integrity, how are the SO and IO tested?
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First, bring axis of eye into alignment with long axis of muscle by tracking a finger medially (adduct), then track up (IO) or down (SO)
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If there is injury to CN IV, what would be the position of the lesioned eye?
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Extorted (SO dysfunction)
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If there is injury to CN VI, what would be the position of the lesioned eye?
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inward (LR dysfunction)
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If there is injury to CN III, what would be the position of the lesioned eye?
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down and out (SR, MR, IR, Io dysfunction)
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What is the term that describes an inability to direct both eyes towards same object?
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strabismus
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What is the clinical term for double vision?
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diplopia
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How would a patient compensate eye movement for a lesion in CN VI?
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paralysis of LR, Px compensates byturning their head so that the object is brought into alignment with the affected eye
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How would a patient compensate eye movement for a lesion in CN IV and with what action do they have the most trouble?
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Paralysis of SO, so patient compensates by tilting their head towards the unaffected side - patient experience difficulty walking down stairs
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What is the differential diagnosis regarding cranial nerves for a patient presenting with a tilted head?
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Lesion of CN IV affecting SO; or a lesion of CN XI causing torticollis (affected SCM muscle)
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A lesion of CN III, resulting in oculomotor ophthalmoplegia, presents with what symptoms?
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eyes move down and out (strabismus); ptosis (Px compensates by raising frontalis m); dilated pupil, lack of accomodation
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Which cranial nerve provides parasympathetic motor innervation to the ciliary muscles and constrictor pupillae?
|
CN III
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Which cranial nerves provides sensory innervation to the eye, eyelids, conjunctiva, orbit, forehead, and lacrimal gland?
|
CN V(1 and 2)
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Sympathetic motor innervation to the eye supplies which structures?
|
dilator pupillae, superior tarsal muscle, lacrimal gland
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Which cranial nerve provides parasympathetic innervation to the lacrimal glands?
|
CN VII, also provides motor innervation to the orbicularis oris
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From which nuclei in the midbrain do the somatic and parasympathetic nerves of CN III originate, respectively?
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somatic: oculomotor nucleus
parasympathetic: edinger-westphal nucleus |
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Pathology of which structures can cause dysfunction of the oculomotor nerve (CN III)?
|
posterior cerebral a.
superior cerebellar a. cavernous sinus superior orbital fissure |
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The SUPERIOR division of CN III provides innervation to which muscles?
|
SR, levator palpebrae
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The INFERIOR division of CN III provides innervation to which muscles?
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IO, IR, MR
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What is the pathway that the axons of CN IV (trochlear motor n.) take?
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trochlear nucleus in the BS --> axons cross in midbrain--> exit dorsal aspect of the brain and wrap around to emerge b/w the pons and temporal lobe --> b/w posterior cerebral and superior cerebellar a. --> through the cavernous sinus and superior orbital fissure --> SO
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Which is the only cranial nerve that emerges on the posterior aspect of the brain?
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CN IV - trochlear motor n.
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Where are the nuclei of CN VI (abducent motor n.) located and what loops around them?
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abducens nuclei in pon in floor of the 4th ventricle - CN VII axons loop around nuclei
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What is the pathway that the axons of CN VI (abducent motor n.) take?
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Exit BS b/w pons and medullary pyramids (past basilar a. and pontine branches) -->post. cranial fossa --> pierce dura and run along petrous temporal bone (by ear) --> through cavernous sinus and superior orbital fissure --> LR
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Which of the nerves innervating the eye has the longest intracranial course?
|
CN VI
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What do the postganglionic axons of the parasympathetic division of CN III travel through after exiting the ciliary ganglion?
|
short ciliary nerves (considered part of CN V along with the long ciliary n)
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Axons of what nerves run through the short ciliary nerve?
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parasympathetic motor axons of CN III, sensory axons of V, sympathetic motor axons of CN V
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What is accomodation and what coordinates it?
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adaptation of the eye for near vision -- coordinated by the cortex
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During accomodation, how do signals travel from sensory input to motor output?
|
sensory info travels up CN II to visual cortex --> CN III contracts MR mm, ciliary mm (decrease tension in the eye) and constrictor pupillae mm
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What two responses are seen in the pupillary light reflex and how do they come about?
|
direct: response in illuminated eye; consensual: response in contralateral eye - direct sensory input from one eye will travel to Edinger-Westphal nuclei which will then project into BOTH eyes
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How is a lesion of CN III (left OR right nerve) diagnosed clinically?
|
pupillary light reflex will not cause pupillary constriction in direct eye, but will cause constriction in the consensual eye - i.e. the side that does not have the lesion
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How does sympathetic innervation reach the lacrimal gland?
|
postganglion fibers travel along the carotid plexus --> deep petrosal nerves --> lacrimal gland
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|
What structures run through the cavernous sinus?
|
ICA, CN III, IV, V1, V2, VI
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Aneurysms of the posterior cerebral or superior cerebellar arteries would affect which cranial nerves?
|
III, IV
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Aneurysms of the basilar a. and pontine branches can affect which structures?
|
CN VI (and descending corticospinal tracts)
|
|
What is accomodation and what coordinates it?
|
adaptation of the eye for near vision -- coordinated by the cortex
|
|
During accomodation, how do signals travel from sensory input to motor output?
|
sensory info travels up CN II to visual cortex --> CN III contracts MR mm, ciliary mm (decrease tension in the eye) and constrictor pupillae mm
|
|
What two responses are seen in the pupillary light reflex and how do they come about?
|
direct: response in illuminated eye; consensual: response in contralateral eye - direct sensory input from one eye will travel to Edinger-Westphal nuclei which will then project into BOTH eyes
|
|
How is a lesion of CN III (left OR right nerve) diagnosed clinically?
|
pupillary light reflex will not cause pupillary constriction in direct eye, but will cause constriction in the consensual eye - i.e. the side that does not have the lesion
|
|
How does sympathetic innervation reach the lacrimal gland?
|
postganglion fibers travel along the carotid plexus --> deep petrosal nerves --> lacrimal gland
|
|
What structures run through the cavernous sinus?
|
ICA, CN III, IV, V1, V2, VI
|
|
Aneurysms of the posterior cerebral or superior cerebellar arteries would affect which cranial nerves?
|
III, IV
|
|
Aneurysms of the basilar a. and pontine branches can affect which structures?
|
CN VI (and descending corticospinal tracts)
|
|
CN V provides SENSORY innervation to what structures?
|
face, oral and nasal caivities, eye and orbit, meningeas, nasopharynx glands, anterior 2/3 of the tongue, teeth, gums, part of ear (all GSE)
|
|
CN V provides MOTOR innervation to what structures?
|
muscle of masstecation (temporalis, masseter, medial and lateral pterygoids), as well as tensor palatini, tensor tympani, mylohyoid, and anterior belly of digastric (all derived from the 1st pharygeal arch) (GVE)
|
|
What are the three main branches of the trigeminal nerve?
|
V1 - ophthalmic
V2 - maxillary V3 - mandibular |
|
What is special about the terminal branches of CN V?
|
serve as acess route for parasymp and symp postganglionic axons to visceral structures`
|
|
What component of CN V synapses in the mesencephalic nucleus and what does it innervate?
|
proprioceptive component - innervates all skeletal muscle innervated by CNs except for trapezius and SCM
|
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Where are the SECOND order neurons (GSE) of CN V located?
|
pontine nucleus, spinal trigeminal nucleus (continuous w/ dorsal horn of spinal cord) in BS
|
|
Where are the FIRST order neurons (GSE) of CN V located?
|
semilunar (trigeminal) ganglion
|
|
Where are the motor neurons of CN V located and through which branch of CN V do they travel?
|
masticatory muscles (trigeminal nucleus) in brain stem and travel through the mandibular branch
|
|
What type of sensory information is handled by the pontine and spinal trigeminal nuclei, respectively?
|
pontine: tactile, pressure, spinal: pain, temp, and some tactilie
|
|
What order neurons are found in the mesencephalic nucleus, where do their central processes travel and what is the clinical significance of this?
|
1st order, central processes synapse in certain brain regions including the motor nucleus of V (important for monosynaptic stretch reflex; jaw-jerk)
|
|
How does CN V travel from its origin on the BS to its three-way split?
|
CN V emerges from mid-lateral surface of pons as large sensory root and a smaller motor root --> middle cranial fossa depression (=trigeminal/meckel's depression) containing the semilunar ganglion from which it splits
|
|
98. Through what structures do the ophthalmic (V1), maxillary (V2), and mandibular(V3) divisions of CN V travel to gain access to the cranial cavity?
|
superior orbital fissure: V1
foramen rotundum: V2 foramen ovale: V3 (motor root joins it sensory root just outside of this) |
|
Which divisions of CN V travel through the cavernous sinus?
|
V1 and V2
|
|
What is the first (little) branch to come off V1 and what does it innervate?
|
meningeal branch (in CS) - innervates the dura; tentorium cerebelli; falx cerebri
|
|
What are the three main branches that come off V1?
|
nasociliary
frontal lacrimal |
|
What components run through the short ciliary nerve?
|
sensory fibers from CN V, parasymp postgang fibers from CN III, postgang symp fibers from superior cervical ganglion
|
|
What components run through the long ciliary nerve?
|
sensory fibers from CN V, postgang symp from superior cervical ganglia
|
|
What branch off of the nasociliary nerve innervates the ethmoid and sphenoid sinuses and what does this branch travel through?
|
posterior ethmoidal branch - nasal branch (goes through the nasal cavity, gives off external nasal branch which provides sensory innervation to the skin of the nose
|
|
What are the two terminal branches of the nasociliary nerve?
|
infratrochlear and palpebrae
|
|
What are the two major branches that split off of the frontal nerve and what do they provide innervation to?
|
supraorbital and supratrocheal - provide sensory innervation to forehead, eyelid, scalp, and conjunctiva
|
|
The lacrimal branch of the nasociliary nerve carries fibers from what nerves?
|
sensory from V1, postganlionic parasymp from from VII, symp postganglionic fibers
|
|
What does the meningeal branch of V2 innervate?
|
first branch in CS, provides sensory innervation to anterior and middle cranial fossa
|
|
In what locations do the main branches of V2 split off?
|
pterygopalatine fossa, infratemporal fossa, infraorbital canal
|
|
What do the short roots coming off V2 suspend in the pterygopalatine fossa?
|
pterygopalatine ganglia
|
|
What branches does V2 give off in the pterygopalatine fossa and what do they innervate?
|
orbital (periosteum of the orbit)
greater palatine (hard palate, gums) posterior superior nasal (nasal cavity) pharyngeal (nasopharynx) |
|
What branches split off the greater palatine branch of V2 in the greater palatine canal?
|
posterior inferior nasal branches, lesser palatine nerves (innervate soft palate tonisl)
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What is an important major branch that splits off of the posterior superior nasal branch of V2 and what does it innervate?
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nasopalatine nerve (innervates the nasal septum) then goes through the incisive canal to innervate the hard palate
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What two major branches come off V2 in the infratemporal fossa?
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zygomatic branch and posterior superior alveolar branches
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What three branches are provided by the zygomatic branch of V2?
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communicating branch that meets with the lacrimal nerve (V1) carrying parasymp (CN VII) and symps; zygomaticofacial and zygomaticotemporal
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What branches of CN V innervates the teeth and gums?
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posterior superior alveolar branches that come off V2 in the infratemporal fossa; anterior superior alveolar and middle superior alveolar branches of V2 arising in the infraorbital canal; inferoir alveolar branch of V3 after passing through the mandibular foramen
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What branches come off V2 in the infraorbital canal?
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anterior superior alveolar, middle superior alveolar, terminal branches: superior labial, palpebrae and laternal nasal
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Pathology of the middle meningeal artery can cause problems concerning which nerves?
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meningeal nerves (of V3) and auriculotemporal nerve (from posterior division of V3)
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After giving off its meningeal branch, V3 passes through which ganglion before giving off its motor branches?
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otic ganglion (CN IX)
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What are the major motor branches that come off V3?
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medial pterygoid, tensor veli palatini, tensor tympani
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What branches split off the anterior division of the mandibular nerve?
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3 motor, 1 sensory: massester (m), lateral pterygoid (m), temporalis (m), buccal (s)
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What branches split off the posterior division of the mandibular nerve?
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auriculotemporal, lingual, and infeior alveolar
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How does the auriculotemporal nerve arise, where does it travel, and what does it innervate?
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arises from two auriculotemporal rootsf posterior division of V3 after they wrap around the middle meningeal a.- is joined by the parasymp of IX, and travels through the parotid gland
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What does the auriculotemporal nerve innervate?
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provides sensory information to the parotid gland, TMJ, external auditory meatus, tympanic memb
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What is ganglion is suspended from the lingual branch of the posterior division of V3?
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submandibular
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What is the lingual branch of the posterior division of V3 joined by as it travels to the submandibular and sublingual glands?
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chorda tympani of VII carrying taste and parasymp motor fibers
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What does sympathetic innervation to the submandibular and sublingual glands hitch-hike on?
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lingual branch of the posterior divison of V3
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What structures does the lingual branch of the posterior division of V3 provide sensory innervation to?
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anterior tongue and gums
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What motor nerve does the inferior alveolar branch of the posterior division of V3 give rise to?
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mylohyoid nerve to mylohyoid m and anterior belly of the digastric
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What does the inferior alveolar branch of the posterior division of V3 pass through to provide innervation to the lip and skin of the chin?
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mental foramen
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Besides the alveolar nerves, which two nerves can provide sensory innervation to the gums?
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lingual nerve of V3, and greater palatine nerve from V2
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How do signals travel in the jaw-jerk reflex?
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sensory in via proprioception fibers traveling in motor branches of CN V --> mesencephalic nucleus --> central processes synapse in the motor nucleus of CN V --> motor axons are sent bilaterally to the massester muscle
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What is a clinically more useful way of testing the integrity of CN V that using the jaw-jerk reflex?
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ask Px to clench teeth and palapte the masseter muscle
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When testing the corneal reflex by running a swab over the cornea and looking for a bliking reflex, how do the signals travel?
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sensory via long and short ciliary nn. --> semilunar ganglion --> central processes --> synapse on the pontine trigeminal nucleus --> bilateral projections to CN VII motor nuclei --> orbicularis oris m
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Lesions of V1 or V2 would result in what?
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ipsilateral sensory loss in the field of distributuion
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A lesion of V3 what result in what?
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Ipsilateral sensory loss in field of distribution and ipsilateral paralysis of muscles innervated by the mandibular nerve (problems chewing, swallowing, speaking)
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