Question

Parietal cells secrete-
A) Pepsinogen.
B) Mucus.
C) Lysozyme.
D) Intrinsic factor.
E) Parathormone

Answer 1

Hint: Parietal cells are a type of glandular cells, found in the epithelial lining of the stomach. The glandular epithelium is a type of epithelial tissue which covers the glands of our body. The main function of these cells is secretion. Both exocrine and endocrine glands secrete their secretion through the glandular cells.

Complete answer:
Parietal cells also known as oxyntic cells are present in the epithelial lining of the stomach and produce hydrochloric acid and intrinsic factors. These parietal cells are present in the cardia and fundus regions of the stomach. HCL produced by them helps in maintaining the acidic environment inside the stomach which is essential for protein digestion to begin. HCL converts pepsinogen (inactivated form) into pepsin (active form) which can then act in protein to convert it into peptides or peptones. Intrinsic factors released by parietal cells play an important role in the transportation and absorption of vitamin B12.
Pepsinogen is a proenzyme which is secreted by the peptic or chief cells of gastric glands. They are converted into active enzyme pepsin by the action of HCl in them. Pepsi converts proteins into protests and peptones.
Mucus is secreted by the mucus neck cell of gastric glands present in the stomach. They protect the mucosal epithelium of the stomach from corrosion by the highly concentrated hydrochloric acid by lubricating them.
Lysozyme is present in saliva. They act as an antibacterial agent and prevent infections.
Parathormone is a hormone released by the parathyroid gland. The secretion of parathyroid hormone is regulated by circulating levels of calcium ions.

Hence correct answer is option C) Parietal cells secrete intrinsic factors.

Note:
The mucosa layer of the stomach has gastric glands. There are three major types of gastric cells- mucous neck cells, peptic or chief cells, parietal or oxyntic cells. HCl provides an acidic pH of 1.8 which is optimal for the pepsin to work. Small amount of lipases are also secreted by gastric glands. The food mixes thoroughly with the gastric juice of the stomach and is called chyme.