2 A Flashcards
What is the purpose of prostaglandins?
To enhance mucus production to protect the lining of the stomach.
Which part of the stomach is closest to the duodenum?
The pyloris
What type of cells secrete mucus in the stomach?
Mucous neck cells
What type of cells secrete HCL and Intrinsic Factor?
Parietal cells
What type of cells secrete pepsinogen and gastric lipase?
Chief cells
What do endocrine cells secrete in the stomach?
Gastrin, Histamine
What substances disrupt the mucosal barrier of the stomach?
Ethanol, bile salts, NSAIDs and H. pylori
What is the role of the vagus nerve in the cephalic on the stomach?
Vagus nerve weakly stimulates gastric juice secretion
Vagus nerve stimulates gastrin secretion which further stimulates the secretion of gastric juice.
What occurs during the gastric phase?
Distention of the stomach and protein digestion products stimulate gastrin secretion. Vagus nerve still stimulates gastrin release and gastric motility. Elevated levels of gastrin signal the release of histamine which in turn increases the release of HCL.
What occurs in the intestinal phase?
Small amounts of acid chyme are released into the duodenum which causes the release of three substances that inhibit the release of gastric juices.
What are the three substances released in response to chyme entering the small intestine?
CCK (cholycystokinin)
Secretin
Gastric Inhibitory Peptide
What is the enterogastric reflex?
It occurs when products of protein digestion and H+ in the duodenum inhibit vagus nerve activity. Fatty acid chyme also stimulates the release of CCK, secretin, and GIP all of which inhibit gastric motility and emptying.
