Hormones Controlling Metabolism

Question 1

Parietal cell secretions and stimulatory factors

Answer 1

HCl, intrinsic factor

Stimulatory influences: Histamine (H2), vagal ACh, gastrin, caffeine,

Question 2

Chief cell secretions

Answer 2

Secrete pepsinogen and chymosin.

Pepsinogen is activated through cleavage to pepsin by HCl

Question 3

Cells present in the crypts of the gastric lining of the stomach

Answer 3

Parietal, mucous, G cells, chief cells, neuroendocrine cells, D cells

Question 4

Cephalic phase of digestion

Answer 4

Responsible for 10% of gastric secretion
Occurs in response to the sight, smell or taste of food.
Stimulates gastric secretion of HCl in preparation for the intake of food

Question 5

Gastric phase of digestion

Answer 5

Responsible for 50 % of gastric secretion

Occurs in response to distension of the stomach as food enters

Question 6

Intestinal phase of digestion

Answer 6

Responsible for 40% of gastric secretion

Occurs in response to acid chime entering the intestines

Question 7

Gastrin: Cell released from, release stimulated by, actions

Answer 7

Released from G cells
It’s release is stimulates by ACh from parasympathetic neuron (vagus)
Acts upon parietal cells to stimulate the secretion of HCl and intrinsic factor, increases gastric motility

Question 8

Function of chief cells

Answer 8

Secrete pepsinogen. Inactivate and packaged to prevent self-digestion of the stomach
Pepsinogen is cleaved into pepsin by HCl

Question 9

Somatostatin: Cell released from, release stimulated by, actions

Answer 9

Released from D cells.
Release is continuous
Acts to decrease the secretion of HCl

Question 10

Secretin: Cell released from, release stimulated by, actions

Answer 10

Released from S cells
Release is stimulated by the entry of acidic chyme into the duodenum
Acts to decrease HCl secretion, decreases gastric emptying and increases the released of bicarbonate from the pancreas (pancreatic juice), stimulates contraction of the gallbladder

Question 11

Cholecystokinin (CCK): Cell released from, release stimulated by, actions

Answer 11

Released from I cells
Release is stimulated by the entry of chyme containing fatty acids and amino acids into the duodenum
Acts to increase the secretion of bile from the gallbladder and of pancreatic juice, inhibits gastric emptying and motility

Question 12

VIP (vasoactive inhibitory peptide): Cell released from, release stimulated by, actions

Answer 12

Released from enteroendocrine cells
Released in response to the entry of chyme into the small intestine.
Acts to inhibit gastric secretions, stimulates buffer secretion, stimulates dilation of intestinal capillaries

Question 13

GIP (gastric inhibitory peptide): Cell released from, release stimulated by, actions

Answer 13

Released from enteroendocrine cells.
Released in response to chyme rich in fatty acids and glucose entering the duodenum.
Acts to induce the secretion of insulin, Inhibits gastric secretion and motility.

Question 14

Enterogastric reflex

Answer 14

The entry of chyme into the small intestine prompts inhibitory signals being sent to the stomach via the myenteric plexus.