Question

The cells of the epithelial linings in the vertebrate stomach is not damaged by HCl because of
A. Mucus secretion covering the epithelium
B. Neutralization of HCl by alkaline gastric juice
C. HCl being too dilute
D. Epithelium being resistant to HCl

Answer 1

Hint: The food is the source of energy that is required for our survival. We eat food through our mouth where it is chewed by teeth into smaller pieces. It is mixed with saliva and it is swallowed after mixing with saliva. It passes through oesophagus without any change to the stomach for further digestion.

Complete answer:
When the food reaches in the stomach, it stays here for some time. The stomach contains glands in its mucosal layer. There are three types of glands in the stomach like fundic, cardiac, and pyloric glands. These glands secrete mucus, hydrochloric acid and gastrin hormone that promotes the secretion of hydrochloric acid gastric glands.

HCl has many functions. It kills the bacteria, the hard materials present in food like bone are converted into soft one, and it creates an acidic environment for the action of enzyme pepsin that digest proteins into peptones and proteases.

The pH of HCl is 1-2 in the stomach. If we eat a non-vegetarian diet, it can be digested through our alimentary canal. The mucus is secreted by the glands of stomach mucosa that makes a covering over the wall of the stomach, which protects the lining of the stomach from the harmful action of HCl.

Hence, the correct answer is option (A).

Note: If the secretion of mucus is disturbed in any person, it starts secreting more acid. Due to the effect of high acid concentration in the stomach, the epithelial lining of the stomach will also get affected due to the action of HCl. It caused the generation of the peptic ulcers in the wall of the stomach.