GI hormone regulation, motility mechanisms, and digestive and absorptive processes tested on USMLE Step 1.
34 cards · basic cards · AI-written, checked twice. Edit anything.
- Where are gastrin-secreting G cells located?
- Antrum of the stomach
- What is the primary action of gastrin?
- Stimulates parietal cells to secrete HCl (gastric acid)
- What stimulates gastrin secretion?
- Vagal stimulation, stomach distention, and luminal peptides/amino acids
- Where are CCK-secreting I cells located?
- Duodenum and jejunum
- What effect does CCK have on the gallbladder?
- Stimulates gallbladder contraction
- What effect does CCK have on the pancreas?
- Stimulates secretion of pancreatic digestive enzymes
- What stimulates CCK secretion?
- Fatty acids and amino acids in the duodenum
- Where are secretin-secreting S cells located?
- Duodenum
- What effect does secretin have on the pancreas?
- Stimulates secretion of bicarbonate-rich fluid from pancreatic ducts
- What effect does secretin have on gastric acid secretion?
- Inhibits it
- What stimulates secretin secretion?
- Acid (low pH) in the duodenum
- What is the main effect of GIP (glucose-dependent insulinotropic peptide)?
- Stimulates insulin release from the pancreas
- What is the main function of motilin?
- Stimulates migrating motor complexes during fasting
- What is the main function of somatostatin in the GI tract?
- Inhibits secretion of gastric acid and virtually all other GI hormones
- What is the main action of vasoactive intestinal peptide (VIP)?
- Relaxes GI smooth muscle and sphincters, and stimulates intestinal secretion