Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
55 Cards in this Set
- Front
- Back
exocrine secretions from pancreas (2)
|
aqueous juice
enzyme juice |
|
endocrine secretions from pancreas (2)
|
glucagon
insulin |
|
aqueous juice is secreted by
|
centro-acinar cells
duct cells |
|
enzyme juice is secreted by
|
pancreatic acinar cells
|
|
glucagon is secreted by
|
alpha cells
|
|
insulin is secreted by
|
beta cells
|
|
functions of aqueous juice (2)
|
(1) neutralizes acidic chyme from stomach
-allows pancreatic enzymes to function in their optimal neutral range - prevents damage to duodenal mucosa by gastric acid - inactivates pepsin (2) dilutes enzyme juice |
|
Secretion rate (slow and fast) vs. composition of aqueous secretion
[Na] [HCO3] [Cl] [K] |
[Na] high at both slow and fast secretion rates
[HCO3] low at slow secretion rates and high at fast secretion rates* [Cl] high at slow secretion rates and low at fast secretion rates* [K] low at both slow and fast secretion rates * HCO3/Cl exchanger function is higher at slow secretion rates |
|
CFTR (cystic fibrosis transmembrane regulator) chloride channel is activated by
|
secretin
|
|
secretin secretion is stimulated by the presence of
|
gastric acid (acidic chyme)
|
|
secretin action is enhanced by the presence of
|
CCK
|
|
secretin inhibits _____ secretion in the stomach, but stimulates _______ secretion in stomach and pancreatic aqueous secretion
|
gastric acid
pepsinogen |
|
upon presence of fatty acids in the duodenum, ______ is released into the blood
|
CCK
|
|
cystic firbosis is due to
|
blocked or defective CFTR chloride channel
|
|
patients with cystic fibrosis have viscous ______ and _______
|
pancreatic aqueous secretion
pulmonary mucous |
|
pancreatic enzymes are synthesized by ______ cells
|
pancreatic acinar cells
|
|
pancreatic enzyme secretion composition:
*protein digestion *lipid/phospholipid digestion *polysaccharide digestion *nucleotide digestion |
trypsinogen
chymotrypsinogen procarboxypeptidase A procarboyxpeptidase B lipase phospholipase amylase ribonuclease deoxyribonuclease |
|
trypsinogen is activated by (2)
|
enterokinase
trypsin |
|
chymotrypsinogen is activated by
|
trypsin
|
|
procarboxypeptidase A and procarboxypeptidase B are activated by
|
trypsin
|
|
lipase is actiaved by
|
bile salts
|
|
phospholipase is actiaved by
|
bile salts
|
|
amylase is activated by
|
Cl
|
|
during the gastric phase, pancreatic enzyme secretion is stimulated by
|
gastrin
|
|
during the intestinal phase, pancreatic enzyme secretion is stimulated by (2)
|
secretin (acidic chyme)
CCK (fat) |
|
secretin is synthesized by
*cell type *location |
S cells
duodenal muscosa |
|
secretin secretion is stimulated by presence of _____ in the duodenum
|
gastric acid (acidic chyme)
|
|
pancreatic aqueous secretion is synthesized by
|
intestinal duct cells
|
|
characteristics of pancreatic aqueous secretion:
*volume *[HCO3] *[enzyme] |
*volume: high
*[HCO3]: high (neutralizes gastric acid in the duodenum) *[enzyme]: low |
|
secretin inhibits secretion of _____ and release of _____
|
gastric acid
gastrin |
|
secretin stimulates secretion of
|
pepsinogen
|
|
CCK is synthesized by
*cell type *location |
I cells
duodenal mucosa |
|
CCK secretion is stimulated by presence of ______ or _____ in the duodenum
|
fatty acids
amino acids |
|
CCK stimulates ______ and _____ secretion
|
pancreatic aqueous
pancreatic enzyme (pancreatic acinar cells) |
|
contraction of the gallbladder and relaxation of the sphincter of Oddi is stimulated by
|
CCK
|
|
pancreatic enzyme secretion:
*volume *[enzyme] |
*volume: low
*[enzyme]: high |
|
pancreatic enzyme secretion is stimulated by (5)
*Ca mediated *cAMP mediated |
*Ca mediated:
- CCK - ACh - gastrin *cAMP mediated: - secretin - VIP (important when vipomas are present) *secretin and CCK act synergistically* |
|
function of bile salts
|
emulsify fats and steroids in the intestine
|
|
bile is produced and secreted by the
|
liver
|
|
path of bile once it's synthesized by the liver
|
bile canaliculi --> bile ducts --> hepatic ducts --> common bile duct --> duodenum
bile canaliculi --> bile ducts --> hepatic ducts --> cystic duct --> gallbladder |
|
types of bile secretion (2)
|
bile acid independent secretion
bile acid dependent secretion (bile acid serves as a negative feedback mechanism to bile secretion) |
|
bile acid independent secretion
*location (2) *stimulated by |
canaliculi and bile ducts
secretin |
|
bile acid dependent secretion
*location *inhibited by |
parenchymal cells
bile acids returning to liver in portal blood |
|
bile acid synthesis is inhibited by
|
bile acids returning to the liver (negative feedback inhibition)
|
|
bile salts are conjugated with (2)
|
glycine (75%)
taurine (25%) |
|
conjugated bile salts:
*pK *charge at neutral pH *water soluble? *amphipathic? |
*pK: 4
*charge at neutral pH: negative (anionic: -OH and COO- groups) *water soluble at neutral pH?: Yes *amphipathic at neutral pH?: yes (allows bile salts to emulsify and solubilize fats and steroids) |
|
bile salts are deconjugated and dehyodroxylated by
|
intestinal bacteria (distal ileum)
|
|
non-ionic bile acids are absorbed in the
|
small intestine
|
|
concentration of bile in the gallbladder is due to
|
active transport of Na, Cl, and HCO3 out of the lateral membrances of gallbladder epithelial cells
|
|
relative bile concentration:
liver vs. gallbladder |
bile is 10X more concentrated in the gallbladder than in the liver (due to salt and water removal)
|
|
when concentrated, bile forms
|
micelles
|
|
bile micelles are composed of (3)
|
bile salts (80%)
lecithin (15%) cholesterol (5%) |
|
osmotic activity:
bile micelles vs. bile micelle components |
bile micelles have less osmotic activity than individual bile micelle components
|
|
release of bile from the gallbladder is stimulated by (2)
|
CCK
vagus n. |
|
gallstone formation:
*stages (3) *location |
*supersaturation of cholesterol
- occurs in the liver *nucleation and precipitation (seeding of cholesterol cyrstals or microstones) - occurs in the gallbladder *growth of microstones to form macrostones |