Gastric Secretion, Peptic Ulcer Disease, and H. Pylori Flashcards
What do mucus cells secrete
mucus, pepsingoen II
parietal cell secretion
HCl, IF
Chief Cell secretion
Pepsinogen I
D Cell
Somatostatin
G cell secretion
Gastrin
Mast Cell secretion
Histamine
Enterochromaffin cell secretion
histamine
what cells are located in the crypts of the villi of the stromach?
Chief cells mainly, some ECL cells and some parietal cells.
role of somatostatin
negative regulates the parietal cells (that secrete HCl), prevents acid from being released. somatostatin irs realeased from the D cells.
fundus function
storage
the body of the stomach has ___ galnds, which contain
oxyntic glands, which contain parietal cells, mucus cells, ECL cells, and chief cells.
the antrum of the stomach has ___ glands, which contain
pyloric glands, which contain mucus cells, G cells (gastrin) and D cells (somatostatin)
Food, amino acids, and vagus nerve stimulation stimulates ___ cells to produce _____, which signals ECL cells to produce ____< which ___ acid production via proton pump
Food, amino acids, and vagus nerve stimulation stimulates G cells to produce gastrin, which signals ECL cells to produce histamine< which INCREASES acid production via proton pump
prostaglandins and somatostatin ____ acid production
decrease
PPIs act on what part of the mechanism of acid secretion
at the end stage. it inhibits the proton pump which usually pumps H+ into the lumen from HCl (of the parietla cells)
H2 blockers act on what part of the mechanism
they block histamine that was released from the ECL cells that were activated by acetylcholine (from vaus nerve), food, AA etc. H2 blockers prevent parietla cells from releasing HCl
3 phases of gastric acid secretion
cephalic phase
gastric phase
intestinal phase
outline the processes of the cephalic phase
effective stimuli including conditioned reflexes, smell, taste chewing swallowing, hypoglycemia.
the cephalic phase is mediated by the ___ nerve. outline
by the vagus nerve. Ach acts on the G cell via Gastrin releasing peptide to stimulate gastrin release. this acts on the parietal cells. Ach also can act directly on the parietla cell to induce acid secretion.
mechanisms that stimulate the gastric acid secretion during the gastric phase of digestion
- distention, stimulates the vagus nerve which releases Ach onto parietal cells and G cells to promote H+ release
- Amino acids– peptides can stimulate G cells to release gastrin which influence parietal cells to promote H+ release
when is gastrin release inhibited during gastric phase
if the pH is low enough. gastrin stops getting released to stop parietal release of HCl.