Unit 3 - Formative 4 D1 Monday

Front 1

Regarding constipation, what is colonoscopy useful for?

Back 1

Useful to identify lesions which narrow or occlude the bowel

Front 2

Regarding constipation, when is radiography useful (plain films of the abdomen or barium enema)?

Back 2

Useful to detect structural causes of constipation and fo rthe diagnosis of megacolon and megarectum

Front 3

Regarding constipation, when are colonic transit tests warranted?

Back 3

Useful in patients whose major complaint is infrequent defecation

Front 4

A patient presents with excessive straining, incomplete evacuation and occult bleeding. Is this primary or secondary constipation?

Back 4

Secondary

Front 5

A patient presents with a CC of constipation with abdominal pain and rectal bleeding. Is this primary or secondary constipation?

Back 5

Secondary

Front 6

A patient presents with changes in voice register, cold intolerance and constipation. The constipation is secondary to what disease?

Back 6

Hypothyroidism

Front 7

On rectal exam, you note a gaping and asymmetrical anal opening. What kind of secondary constipation disease does this suggest?

Back 7

Neurologic disorder impairing sphincter function

Front 8

Patient's over 50 with constipation should always get what?

Back 8

Colonoscopy for colon cancer; complete examination of the colon necessary to exclude a structural disease (colon cancer, colonic stricture) w/ recent change in bowel habits, blood in stool, or weight loss

Front 9

What kind of drugs are significantly associated with constipation?

Back 9

Opioids for chronic pain; diuretics, antidepressants,antihistamines, antispasmodics (calcium channels), anticonvulstants (calcium channels) and aluminum containing antacids

Front 10

A patient presents with a proximally enlarged bowel which is narrowed distally. What is occuring in this disease?

Back 10

Hirschsprung's disease; absence of ganglion cells in distal bowel results in overstimulation of nerves in affected region, resultin gin contraction (similar to achalasia)

Front 11

A patient who recently returned from Africa reports constipation. They note that a few weeks ago they had fever and malaise. What should you consider?

Back 11

Chaga's Disease; caused by Trypanosoma cruzi via insect vector

Front 12

A patient presents with prolonged and excessive straining before elimination. You decide a patient has defecatory or rectal evacuation disorders; what kind of primary constipation is this?

Back 12

Pelvic Floor Dysfunction

Front 13

A young female presents with less than 1 bowel movement a week. She notes a lack of urge to defecate, malaise, and fatigue. What kind of primary constipation is this?

Back 13

Slow - transit constipation;

Front 14

How can you measure colonic transit time?

Back 14

Pt swallows radiopague markers in gelatin capsule; abdominal x ray 120 hours after ingestion; retention in colon of radiopaque markers 5 days after ingestion = slow transit

Front 15

What kind of conservative treatment must be attempted before anorectal testing?

Back 15

Increased dietary fiber and liquids, elimination of medications with constipating side effects

Front 16

How long does it take to expel a 50ml water filled balloon normally?

Back 16

1 minute; abnormal expulsion indicates impaired evacuation

Front 17

What does pelvic floor dysfunction refer to?

Back 17

Inability to empty rectum effectively bc of incoordinated abdominal, rectoanal, and pelvic floor muscles; constipation is functional

Front 18

A patient presents with recurrent abdominal discomfort 3-5 days a month in the last 3 months associated with improvement with defecation, onset associated with a change in frequency and appearance of stool. What is the diagnostic of?

Back 18

Irritable Bowel Syndrome

Front 19

What are the four functions of the colon?

Back 19

1. absorption of water/electrolytes
2. absorptoin of short chain FA
3. storage and transport of undigested/waste material
4. elimination of undigested material/waste products

Front 20

Endoscopy reveals a 'leaky' ileocecal valve. How would you expect this to affect transit time?

Back 20

Slows transit time bc when the ascending colon contracts it will push contents back through valve, increasing transit time

Front 21

Are there dominantly aerobic or anaerobic species in the colonic microflora?

Back 21

Anaerobic

Front 22

What essential things do microflora in our colon produce?

Back 22

K, B1, and B2 (vitamins)

also short chain fatty acids when these organisms die

If bacteria were eliminated the intestines would atrophy

Front 23

What is required for ileocecal sphincter emptying?

Back 23

The colon must be empty; if so, pressure and chemical irritation relax sphincter and excite peristalsis

Front 24

What is the large intestine transit time?

Back 24

48-72 hours; average is around 65 hours

Front 25

What effect does sympathetic stimulation have on GI valves?

Back 25

Closes them down; pyloric, ileocecal, anal (fight or flight)

Front 26

Describe the histology of the colon?

Back 26

FLAT, simple columnar epithelia, crypts with no villi, huge goblet cell density, lots of lymphocytes in lamina propria (purple dots when stained w/ H&E) - might see lymph nodules

Front 27

What do the colonic crypts secrete?

Back 27

Mainly secrete alkaline mucus; mucus secretion increased by parasympathetic stimulation

Front 28

What sympathetic nerve innervates the proximal colon?

Back 28

Vagus

Front 29

Which nerves innervate the distal colon, rectum and anus?

Back 29

Pelvic nerves (S2-S4)

Front 30

What is the sympathetic input to the rectum and anal canal?

Back 30

Hypogastric plexus

Front 31

What ganglion supplies the sympathetic input to the distal colon?

Back 31

Inferior Mesenteric Ganglion

Front 32

Which nerve ganglion supplies the proximal colon?

Back 32

Superior Mesenteric Ganglion

Front 33

Which nerves innervate the external anal sphincter?

Back 33

Pudenal nerves

Front 34

Why doesn't the myenteric plexus completely surrounding the large intestine?

Back 34

It is only under the tenae coli, which are three longitduinal muscle bands that contract to form the haustra

Front 35

What is the function of haustral contractions?

Back 35

To mix chyme; enhances fluid/electrolyte absorption

Propels fecal material (mass movements)

Front 36

Describe the frequency of haustral contractions

Back 36

appear/disappear every 30-60s; require contraction of longitudinal and circular SM

Front 37

Distension of what two structures would cause mass movement in the colon?

Back 37

Gastrocolic reflex (distention of stomach) and duodenocolic reflex (distension of duodedenum)

Front 38

How long does it take food you eat to reach the large intestine?

Back 38

6-8 hours

Front 39

Which plexus carries the intrinsic defecation reflex (stretching of internal anal sphincter)?

Back 39

Myenteric plexus

Front 40

Describe the intrinsic defecation reflex

Back 40

Stretching of internal anal sphincter causes upstream muscularis to contract and internal sphincter to relax

Front 41

Describe the parasympathetic defecation reflex

Back 41

Stretching of rectum sends sensory signals to spinal cord, splachnic nerves return signals intensifying peristalsis

Front 42

Describe the sequence of events when you want to go to the bathroom

Back 42

Pudendal nerve activity to external anal sphincter is inhibited by input from higher brain centers -> external anal sphincter relaxes and higher centers stimulate pelvic floor muscle activity and other defectory actions -> defecation occurs

Front 43

Describe the sequence of events when you don't want to go to the bathroom

Back 43

Pudendal nerve activity is enhanced and the external anal sphincter contracts stronger -> defecation not allowed -> internal anal sphincter contracts and the urge to defecate subsides -> cycle repeats every 10-20 minutes

Front 44

What is the function of the pudendal nerves?

Back 44

External anal sphincter tone

Front 45

Where do fishbones always get stuck?

Back 45

epiglottic vallecula

Front 46

What is a characteristic morphological feature of the duodenal and jejunal lumen?

Back 46

Circular folds/valves of Kerckring

Front 47

Where is the ligament of treitz located?

Back 47

At the duodenojejunal flexure

Front 48

Which part of the biliary system has a spiral appearance?

Back 48

Cystic duct

Front 49

What do the hepatic and cystic duct join to form?

Back 49

Common bile duct

Front 50

Which arteries are along the greater curvature of the stomach?

Back 50

Gastroepiploic artery (left and right gastroomental)

Front 51

Which arteries run along the lesser curvature of the stomach?

Back 51

Gastric arteries (right and left)

Front 52

In an abdominal scan, where does the gas bubble in the stomach always migrate to?

Back 52

the highest point - if laying down it will migrate up toward the pylorus, if standing up it will migrate to the fundus

Front 53

Which aorta is always adjacent and to the left of the vertebra?

Back 53

Abdominal aorta

Front 54

Where does the tail of the pancreas point to?

Back 54

Spleen

Front 55

Where does the head of the pancreas connect?

Back 55

Duodenum

Front 56

what is the relation of the inferior vena cava to the abdominal aorta?

Back 56

the IVC is always to the left of the AA

Front 57

What is the input, output, and function of the insular cortex in relation to ANS?

Back 57

I: VMN of thalamus
O: Amygdala
F: viscerosensory cotex for taste, visceral sensation and pain/temp

Front 58

A patient presents with an inability to taste, feel visceral sensation or pain and temp. What autonomic CNS structure might be damaged?

Back 58

Insular Cortex

Front 59

What is the input, output, and function of the anterior cingulate gyrus in relation to ANS?

Back 59

I: PFC, amygdala
O: PFC, amygdala (reciprocal)
F: Initiates motor/autonomic responses associated with emotional stimuli

Front 60

What is the input, output, and function of the amygdala in relation to ANS?

Back 60

I: Brainstem, thalamus (pain/temp), cerebral cortex (processed sens. info)
O: hypothalamus, brainstem, spinal cord
F: Coordinate autonomic, endocrine, and motor component of emotional response

Front 61

What is the function of the periventricular hypothalamus?

Back 61

Circadian rhythms (suprachiasmatic nucleus SCN)

Front 62

A patient presents with messed up sleep cycles. What ANS related neural structure might be damaged?

Back 62

Periventricular area of the hypothalamus; coordinates circadian rhythms via suprachiasmatic nucleus (SCN)

Front 63

What is the function of the medial area of the hypothalamus?

Back 63

Response to stress via paraventiruclar nucleus PVN

Front 64

A patient presents with a diminished stress response. Which ANS related neural structure might be damaged?

Back 64

Medial area of hypothalamus; diminished stress response due to PVN damage

Front 65

What is the function of the lateral area of the hypothalamus?

Back 65

Arousal; sleepwake cycle; feeding/drinking

Front 66

A patient has a diminished desire to eat or drink. You suspect a neurological lesion where?

Back 66

Lateral hypothalamus

Front 67

Which tract conveys taste/visceral sensation from nucleus of solitary tract to hypothalamus?

Back 67

Dorsal Longitudinal Fasiculus

Front 68

Which tract originates from the PVN and lateral hypothalamic zone to the autonomic nuclei of the brainstem and spinal cord?

Back 68

Hypothalamospinal tract; main hypothalamic output

Front 69

How can you explain the phenomenon of referred pain?

Back 69

The proximity of visceral afferent fibers to the general somatic afferent fibers from the skin for pain produces this phenomenon

Front 70

Where are the preganglionic neurons of the sympathetic system located?

Back 70

IML cell column (T1-L3) of spinal cord

Front 71

What are the two destinations of the sympathetic nervous system neurons?

Back 71

Sympathetic trunk

Prevertebral ganglia (pass sympathetic trunk without synapse to enter splanchnic nerve)

Front 72

What does the prevertebral ganglia give rise to?

Back 72

Splanchnic nerve

Front 73

What neurontransmitters are used by the sympathetic nervous system?

Back 73

Norepenephrine, and Ach/muscarinic cholinergic neurons

Front 74

A branch of CNVII, which ganglion innervates the lacrimal gland, mucosa of nose and palate?

Back 74

Pterogopalatine ganglion

Front 75

A branch of CNVII, which ganglion innervates the submandibular and lingual gland?

Back 75

Submandibular gland

Front 76

A nucleus of CNIII, what nucleus controls the sphincter papillae and ciliaris muscle?

Back 76

Edinger-Westphal nucleus

Front 77

Which parasympathetic division is involved with micturition, defecation, and sexual function?

Back 77

Sacral division, S2-S4

Front 78

Which four cranial nerves make up the parasympathetic cranial division?

Back 78

CN III, VII, IX, X

Front 79

What NT is used by postganglionic parasympathetic innervation?

Back 79

Ach/muscarinic cholinergic receptor

Front 80

Activation of CN V2 branches of the greater palatine nerve, lesser palatine nerve, and nasopalantine nerve all result in what?

Back 80

RUNNY NOSE

Front 81

If histamine in an allergic reaction activates the petrosal nerve pathway of CNVII what is the end result?

Back 81

LACRIMATION

Front 82

If the chorda tympani nerve pathway of CN VII is activated what is the end result?

Back 82

SALIVATION via submandibular/sublingual salivary glands

Front 83

If the CN IX pathway is activated what is the end result?

Back 83

Salivation via parotid gland

Front 84

Which cranial nerve supplies major nerve supply to GI tract?

Back 84

CN X; controls GI motility via myenteric plexus in the foregut and hindgut

Front 85

Activation of CN V2 branches of the greater palatine nerve, lesser palatine nerve, and nasopalantine nerve all result in what?

Back 85

RUNNY NOSE

Front 86

The sacral division of the ANS supplies nerve supply to what structure?

Back 86

Hindgut (last 1/3 of transverse colon, descending colon, sigmoid colon, rectum

Front 87

Describe the sympathetic and parasympathetic innervation of the foregut?

Back 87

S: Greater splanchnic nerve (T5-T9) > Celiac Ganglion > Target

PS: Vagus Nerve

Front 88

If histamine in an allergic reaction activates the petrosal nerve pathway of CNVII what is the end result?

Back 88

LACRIMATION

Front 89

If the chorda tympani nerve pathway of CN VII is activated what is the end result?

Back 89

SALIVATION via submandibular/sublingual salivary glands

Front 90

Describe the sympathetic and parasympathetic innervation of the midgut?

Back 90

S: Lesser (T10-T11) and least (T12) splanchnic nerves > superior mesenteric ganglion > target

PS: Vagus nerve

Front 91

If the CN IX pathway is activated what is the end result?

Back 91

Salivation via parotid gland

Front 92

Describe the sympathetic and parasympathetic innervation of the hindgut?

Back 92

S: Lumbar splanchnic nerves (L1-L3) > inferior mesenteric ganglion > target

PS: Pelvic splanchnic nerves (S2-S4) > pelvic plexus > target

Front 93

Describe the sympathetic and parasympathetic innervation of the internal anal sphincter?

Back 93

S alpha-1 adrenergic receptor
PS: pelvic splanchnic nerves relaxation via VIP, NO or both

Front 94

Which cranial nerve supplies major nerve supply to GI tract?

Back 94

CN X; controls GI motility via myenteric plexus in the foregut and hindgut