Physiology Flashcards
Somatostatin function
Decreases secretion of many other hormones (gastrin bicarb, digestive enzymes)
decreases nutrient absorption from gut by prolonging gastric emptying time
Somatostatin pathway
binds to receptors
activates inhibitory g proteins
deactivates adenylate cyclase which fucks the rest of the mechanism
site of action for somatostatin
Stomach pancreas small intestine liver
Stimulants for Somatostatin release
CCK glucose Vasoactive intestinal peptide
Gastrin function
Induces gastric secretion
Gastrin release
Enteroendocrine G cells of stomach, duodenum
Gastrin stimulants
Acidic content, partially digested food in duodenum, vagus nerve stimulation stomach distension
Secretin Function
Decrease acidity- improves pancreatic enzyme function
Increases pancreatic secretion, bicarbonate and water release
decreases gastric emptying , gastrin release,gastric acid secretion
secretin stimulation/ inhibition
S cells proximal small intestine
Gastric acid, bile salts,fatty acids, ethanol
inhibited by somatostatin
CCK function
promotes food delivery from stomach to small intestine
regulates nutrient stimulated enzyme secretion
increases gallbladder secretion and pancreas enzyme output
what cells secrete CCK
Enteroendocrine I cells
What causes CCK secretion?
Nutrition ingestion, fatty acids,amino acids
Histamine function
Activates parietal cells to release HCL when food is present in the stomach
Chief cells
secrete Pepsinogen
stimulated by gastrin ach and histamine
Parietal
HCL intrinsic factor
