Question

2. Identify the effects of cholecystokinin on the following components of the digestive system:

a. Smooth muscle in the stomach

b. Acinar cells of the pancreas

c. Smooth muscle in the gallbladder

d. Smooth muscle in the duodenal papilla (sphincter of Oddi)

Answer 1

Cholecystokinin is a peptide hormone of the gastrointestinal system secreted by duodenal cells,Which helps digestion of fat and protein.

Stimulus for Cholecytokinin secreation -Entry of Hcl, amino acids, or fatty acids into the duodenum or Stomach.

Action of Cholecystokinin-

1.Smooth muscle in the stomach:

*CCK causes activation of an inhibitory vago-vagal reflex that involves activation of vasoactive intestinal peptide-which causes relaxation of the gastric smooth Muscle-------- Inhibition of gastric emptying.

2.Acinar cells of the pancreas:stimulates tsecreation of a juice rich in pancreatic digestive enzymes which helps the digestion of fat, protein, and carbohydrates.

3.Smooth muscle in the gallbladder:Contraction of Gall baldder-----Gall bladder emptying of Bile.

4.Smooth muscle in the duodenal papilla (sphincter of Oddi): Relaxation of the sphincter of Oddi through release of vasoactive intestinal peptide