Question

Cholecystokinin and secretin are
A. Hormone liberated by the mucosa of the duodenum which stimulates the gallbladder and pancreas respectively.
B. Hormone liberated by the mucosa of the duodenum which stimulates the adrenal cortex.
C. Hormone liberated by the mucosa of the duodenum which stimulates the adrenal medulla.
D. Enzymes that are involved in the digestion of cholesterol and saccharides.

Answer 1

Hint: Hormones are the chemical substances that are secreted by the cells or the tissues directly into the blood. Cholecystokinin and secretin are the hormones of the gastrointestinal system. Duodenum is a part of the small intestine. Cholecystokinin is also called pancreozymin.

Complete answer:
Four hormones are secreted by the small intestine; cholecystokinin, motilin, secretin, and gastric inhibitory peptide(GIP).
Cholecystokinin stimulates the contraction of the gallbladder and releases the stored bile into the intestine.
Secretion of pancreatic juice is also stimulated by cholecystokinin.
‘I' cells produce cholecystokinin and ‘S' cells produce secretin.
So, Cholecystokinin and secretin are the hormones that are liberated by the mucosa of the duodenum which stimulates the gallbladder and pancreas respectively.
The adrenal cortex is stimulated by the ACTH (adrenocorticotropic hormone).
The adrenal medulla is secreted in response to sympathetic nerve stimulation.
Seven alpha hydrolase and pancreatic lipase are the enzymes that digest cholesterol and saccharides.

Hence, the correct answer is option A.

Additional Information:
Pancreatic enzyme and bicarbonate secretion are stimulated by cholecystokinin.
This hormone stimulates the growth of the exocrine pancreas.
Cholecystokinin inhibits gastric emptying.
Secretin inhibits gastric acid secretion and promotes the growth of the exocrine pancreas.

Note:
Cholecystokinin and secretin are the hormones that stimulate the contraction of the gallbladder and pancreatic juices. Secretion of these hormones is due to various stimuli such as fat, carbohydrates, protein, and acid in the intestine. These hormones are secreted by all the parts of the small intestine i.e duodenum, jejunum, and ileum. Pepsin secretion from the stomach is stimulated by secretin.