Question

Organ whose secretion helps in the absorption of vitamin B12 in intestine is
O Small intestine
O Large intestine
O Stomach
O Liver​

Answer 1

The organ whose secretion helps in the absorption of vitamin B12 in the intestine is the Stomach (option 3).

• The stomach lining has 3 types of cells:

1. Mucous Cells: These cells secrete mucous to protect the stomach lining from the corrosive action of hydrochloric acid (HCl).
2. Peptic/Chief Cells: These cells release pepsinogen, which gets activated in the acidic environment of the stomach.
3. Oxyntic/Parietal Cells: These cells secrete hydrochloric acid and Castle's Intrinsic Factor.
4. G Cells: These cells secrete some endocrine hormones.

• Castle's Intrinsic Factor secreted by Oxyntic/Parietal Cells is necessary for the absorption of Vitamin B₁₂.
• Castle's Intrinsic Factor binds with Vitamin B₁₂ in the stomach, thereby protecting it from digestion before reaching the small intestine.
• In the ileum region of the small intestine, Castle's Intrinsic Factor facilitates its absorption.

Thus, the organ whose secretion helps in the absorption of vitamin B12 in the intestine is the Stomach (option 3).