Pancreatic/ Biliary Function - IN Flashcards
1. Doses n Mimosas 2. Champagne n Cocaine
What are the pancreatic endocrine secretions
glucagon, insulin, somatostatin
what are the pancreatic exocrine secretions
secretin, VIP, CCK, ACh, gastrin
what is the main purpose of pancreatic juice
bicarbonate secretion to neutralize that WACK STOMACH ACID GET OUTTA HERE
what secretions increase cAMP
secretin, VIP
what secretions increase intracellular Ca2+
CCK, ACh, Gastrin
do secretin and CCK act synergistically or antagonistically
synergy.
what is the danger of excess VIP
can cause VIPomas (pancreatic tumor type) and gross diarrhea
what type of cells secrete bicarbonate
epithelial duct cells, centro-acinar cells
how is bicarbonate secreted
CO2 diffuses from blood through cell, across basolateral membrane, interacts with carbonic anhydrase to make H+, HCO3-
what happens to venous blood during secretion
it is acidified -> helps negate alkaline tide produced in stomach
does Secretin stimulate or inhibit pancreatic aqueous secretion
stimulate - activates CFTR Cl- channel -> replenishes luminal Cl- needed for Cl-/HCO3- exchange
does CCK stimulate or inhibit pancreatic aqueous secretion
stimulate - primes Na/K ATPase by increasing intracellular Ca2+
What cells release Secretin
S cells - duodenal mucosa
What is “Nature’s Antacid” (hint: not bicarbonate)
Secretin - inhibits gastric secretions and release of Gastrin
What cells release CCK
I cells - in response to fatty acids or AA in duodenum, slows gastric emptying
what role does Vagus nerve have in digestion
none. TID.
just kidding - acts on gallbladder to contract and sphincter of Oddi to relax and release bile - much like CCK
What is the major route of cholesterol and steroid hormone breakdown
hepatic production of bile acids
what is the rate limiting step in bile synthesis
cholesterol-7-a-hydroxylase addition of OH group on C7 of cholesterol
how is net luminal acid secretion maintained in the gallbladder
apical Na/H exchange is slightly faster than apical Cl/HCO3 exchange
what are gallstones composed of
15% lecithin, 80% bile salts, 5% cholesterol
how are gallstones formed
- supersaturation of cholesterol in the liver, 2. nucleation and precipitation, 3. growth of microstones into macrostones
what is cholecystitis
inflammation of gallbladder most commonly caused by blockage of cystic duct by a gallstone
