Choudhury III Flashcards
what are the cells in the pancreas
ductal and acinar cells
describe acinar and ductal secretions from pancreas
acinar are enzyme rich
ductal are HCO3 rich and neutralized acidic chyme
chyme entering duodenuma causes what
duodenal enterendocrin cells to release CCK and secretin
What is role of CCK
induces secretion of enzyme rich pancreatic juice
causes gall bladder to contract and hepatopancreatic sphincter to relax so bile enters duodenum
reduced emptying in stomach
role of secretin
secretion of HCO3 rich pancreatic juice
during what phases does the vagus nerve cause gall bladder to contract
cephalic and gastric
What does enteropeptidase activate
trypsinogen to trypsin
what does trypsin activate
chymotrypsinogen to chymotrypsins proelastase to elastase procarboxypeptidase A to carboxypeptidase A and proc B to cB also activates PLA2
what protects pancreas from prematurely activated enzymes
protease inhibitors that are within the zymogen granules
What controls CCK release?
CCK-releasing peptide and monitor peptide
what cell release CCK
I cells
what inhibits CCK release
trypsin
what releases secretin
S cells in duodenal mucosa
at high rates of secretion what is content of pancreatic secretions
much more Cl andHCO3
not Na and H
(alkaline)
When pH falls in duodenum what is response
S cells secrete secretin
fatty acid meals evoke release of what
secretin
what is achlorhydria
unable to secrete gastric acid
secretin levels in achlorhydria
low
at what percent of pancreatic secretion will there be signs of malabsoprtion and indigestion
less than 10%
most common causes pancreatitis
alcohol abuse and gallstones
how can CF lead to pancreatic insufficiency
thick secretions can obstruct pancreatic duct
what is a key clinical sign of pancreatic insufficiency
steatorrhea
floating feces, oily appearance and foul smelling
what is a hereditary cause of pancreatitis
mutated trypsin that makes it resistant to inhibitors
tryspin eats pancreatic tissue
what drugs can cause pancreatitis
immunosuppressants, anticonvulsants, thiazides
what genetic abnormalities may lead to pancreatitis
SPINK1, CFTR, CTRC
saliva conent in primary aldosteronisms
NaCl zero
K increases to high levels
What is impaired in kwashiorkor
protein digestion
what enzymes are found in brushborder of small intestine epithelial cells
maltase, lactase, sucrase
how are glucose and galactose absorbed in intestines
Na ATP dependent secondary active transport
Na/glucose co transporter
how is fructose absorbed
passive facilitated diffusion
maltose is made up of what?
sucrose?
lactose?
maltose= 2 glucose sucrose= 1 glucose, 1 fructose lactose= 1 galactose, 1 glucose
how are aminoacids and polypeptides transported across basolateral membrane of enterocytes
facilitated or simple diffusion
how is fat absorbed (general)
broken down then rebuilt in cell and transported as chylomicrons
what displaces bile salt molecule from fat-water interface
colipase
