Question

Hormones regulate GI secretion and motility. For gastrin, secretin, cholecystokinin, somatostatin and motilin make a table for each hormone:

• What cells make the hormone
• What is the stimulus that causes the cells to make that hormone
• What is the target tissue for that hormone
• What is the response of the target tissue to the presence of the hormone

Answer 1

	GASTRIN	SECRETIN	CHOLECYSTOKININ	SOMATOSTATIN	MOTILIN
CELLS MAKING HORMONE	G cells in the stomach	S cells present in duodenum and jejunum	Enteroendocrine cells of the duodenum	1.Delta cells of pancreas and duodenum. 2. Hypothalamus	Enteroendocrine cells of the upper small intestine
STIMULUS FOR HORMONE	food ( particularly amino acids) in the lumen of the stomach, hypercalcemia, vagal stimulation.	The acid in the duodenum	Amino acids, fats in the upper part of the small intestine	1.Intake of food which increases the level of glucose and amino acids in blood plasma. 2. Increased level of Growth hormones	fasting which induces alkaline pH in the small intestine
TARGET TISSUE FOR HORMONE	Parietal tissue of the stomach	Pancreas	Gall bladder and pancreatic cells	1.Pancreas, gastrointestinal tract. 2. Anterior pituitary.	small intestine and stomach
RESPONSE OF TARGET TISSUE TO HORMONE	Initiates HCL secretion.	Secretion of bicarbonates which helps in neutralizing the acid in the small intestine to maintain pH.	Secretion of bile from the gall bladder and pancreatic enzymes.	1. Inhibit the secretion of pancreatic hormones and enzymes reduced gastric secretions. 2. Inhibit the secretion of growth hormone.	Increased motility of cells in small intestine and stomach to empty the gut