Lecture 5 - Secretions I Flashcards
10 hormones secreted by the GIT?
- Gastrin
- Secretin
- CCK
- Gastric inhibitory peptide
- Motilin
- Glucagon-Like Peptide (GLP)-1
- Peptide YY
- Ghrelin
- Histamine
- Somatostatin
Site of secretion of gastrin?
G-cells of antrum and duodenum
6 general actions of gastrin?
- Stimulates gastric H+ secretion by parietal cells
- Stimulates antral motility
- Stimulates effective gastric emptying
- Inhibits gastric emptying by maintaining the tone of the pyloric sphincter
- Stimulates gastric mixing
- Stimulates lower GIT motility
4 primary stimuli of gastrin? Which ones are duodenal?
- Stretch
- Peptides**
- AAs**
- Vagus nerve release of gastrin release peptide (GRP)
Site of secretion of secretin?
S-cells of duodenum
3 general actions of secretin?
- Stimulates pancreatic, biliary, and intestinal secretions of buffers, electrolytes, and enzymes
- Inhibits gastric H+ secretion by inhibiting gastrin secretion
- Inhibits gastric emptying by maintaining the tone of the pyloric sphincter
2 primary stimuli of secretin?
- Acidic chyme**
2. Long chain FAs**
Site of secretion of CCK?
I-cells of the duodenum and jejunum
7 general actions of CCK?
- Stimulates pancreatic enzyme secretion
- Contracts gallbladder
- Relaxes sphincter of Oddi
- Inhibits gastric emptying by maintaining the tone of the pyloric sphincter
- Stimulates bile production by liver
- Lower GI motility
- Stimulates chief cells
3 primary stimuli of CCK? Which ones are duodenal?
- Small peptides**
- AAs**
- Fats**
Site of secretion of GIP?
Duodenum and jejunum
Other name for gastric inhibitory peptide?
Glucose insulinotropic peptide
4 general actions of GIP?
- Stimulate pancreatic insulin secretion
- Inhibit gastric H+ secretion and gastrin secretions at HIGH physiologic levels
- Inhibit gastric mixing
- Inhibit gastric emptying by maintaining the tone of the pyloric sphincter
3 primary stimuli of GIP? Which ones are duodenal?
- FAs**
- Glucose**
- AAs**
Site of secretion of motilin?
M-cells of duodenum
General action of motilin?
Stimulates phase III of MMC
Primary stimulus of motilin?
Fasting
Site of secretion of GLP-1?
L-cells of mainly jejunum, and lower small intestine
Site of secretion of peptide YY?
Jejunum and ileum
General action of both GLP-1 and peptide YY?
Inhibit hypothalamic secretion of NPY => satiety
Primary stimulus of GLP-1 and peptide YY?
Chyme
Site of secretion of ghrelin?
Oxyntic cells of stomach = parietal
General action of ghrelin?
Stimulate hypothalamic secretion of NPY => hunger
Primary stimulus of ghrelin?
Fasting