Human Physiology Exam 4

gastrin - secretion

hormone secreted by G cells in the stomach or duodenum (small intestine) in response to presence of proteins

gastrin - function

hormone

stimulates gastric acid secretions and pepsin

promotes gastric motility

helps prepare for/helps process food in digestive system - “turns on” the stomach

gastrin - aid

hormone

helps prepare for/helps process food in digestive system - “turns on” the stomach

cholecytokinin (CCK) - secretion

hormone secreted by I cells in the duodenum or jejunum (small intestine) stimulated by amino acids and fat

cholecytokinin (CCK) - function

hormone

stimulates bile release

stimulates exocrine pancreatic enzyme secretion

slows gastric emptying

promotes satiety

cholecytokinin (CCK) - aid

hormone

helps digest fats and proteins in small intestine

secretin - secretion

hormone secreted by S cells in duodenum (small intestine) stimulated by acid

secretin - function

hormone

stimulates bicarbonate secretion

increases bile production in liver 

inhibits gastric acid secretion

inhibits gastric motility

glucose-dependent insulinotropic peptide (GIP) - secretion

hormone secreted by K cells in duodenum or jejunum (small intestine)

glucose-dependent insulinotropic peptide (GIP) - function

hormone

stimulates insulin release from pancreas in response to nutrient digestion

glucose-dependent insulinotropic peptide (GIP) - aid

hormone

when digesting (especially glucose and fat) tells pancrease to release insulin

motilin - secretion

hormone secreted by M cells in small intestine

motilin - function

hormone

promotes motility during fasting

initiates migrating motor complexes (MMC) during fasting

clears stomach and small intestine using peristalsis

motilin - aid

“housekeeping” hormone, clearing gut

trypsinogen/trypsin -secretion

hormone secreted by pancreas (pancreatic acinar cells) into the duodenum (small intestine)

activated by enterokinase

trypsinogen/trypsin - function

hormone

breaks peptide bonds in proteins into short peptides and amino acids for absorption

“master activator” for other pancreatic enzymes

trypsinogen/trypsin - aid

helps digest proteins

enterokinase

enzyme that activates typsinogen into trypsin

bound to membrane of luminal surface of duodenal cells

pepsinogen/pepsin - secretion

enzyme secreted by chief cells in stomach gastric glands

activated by very acidic pH (pH 1-2) or HCL from parietal cells

pepsinogen/pepsin - function

enzyme that begins protein digestion in stomach

amylase - secretion

enzyme secreted by salivary glands or pancreatic acinar cells

amylase - function

enzyme that digests carbohydrates, specifically starches (long chains of glucose) into smaller sugars

proteases

enzymes that helps digest proteins into smaller peptides and amino acids

secreted by pancreatic acinar cells

lipase and colipases

enzymes that help digestion of fats

secreted by pancreatic acinar cells

brush border enzymes

enzymes located on microvilli of small intestine (mainly duodenum and jejunum)

complete final steps of digestion, producing molecules small enough to be absorbed

produced by enterocytes

“finishers” of digestion

hydrochloric acid (HCL) - secretion

acid secreted by parietal cells in stomach linings

hydrochloric acid (HCL) - function

creates acidic environment - this helps activate pepsinogen

denatures proteins so digestive enzymes can access peptide bonds easier

assists in mechanical and chemical digestion

stimulates hormone release - somatostatin (inhibits digestion when acid is too high) and secretin in duodenum