Inner Lining of Stomach and Protection from Hydrochloric Acid

Introduction:
The inner lining of the stomach is responsible for secreting various digestive enzymes and acids to break down food particles. One of the primary components of gastric juice is hydrochloric acid (HCl), which helps in the digestion of proteins. However, the inner lining of the stomach needs protection from the corrosive effects of HCl.

Mucus as Protection:
The correct answer to the given question is option 'B' - Mucus. The inner lining of the stomach is protected by a layer of mucus that acts as a barrier against the corrosive nature of hydrochloric acid.

Role of Mucus:
Mucus is a thick, slippery substance that is secreted by the stomach's mucous cells. It coats the stomach's inner lining, creating a protective layer. Here's how mucus helps in protecting the stomach:

1. Physical Barrier: Mucus forms a physical barrier between the acidic contents of the stomach and the underlying tissues of the stomach lining. It prevents direct contact between the hydrochloric acid and the delicate cells of the stomach.

2. Neutralizing Effect: Mucus also has a neutralizing effect on the hydrochloric acid. It contains bicarbonate ions that can buffer the acid, reducing its corrosive potential. This helps in maintaining the pH balance within the stomach.

3. Lubrication: The mucus layer acts as a lubricant, allowing the smooth movement of food through the stomach. This helps prevent damage to the stomach lining caused by the abrasive action of food particles.

4. Protecting the Epithelial Cells: The mucus layer protects the epithelial cells that line the stomach. These cells are responsible for producing gastric juice and are vital for the proper functioning of the stomach.

Conclusion:
In conclusion, the inner lining of the stomach is protected from hydrochloric acid by a layer of mucus. Mucus acts as a physical barrier, neutralizes the acid, provides lubrication, and protects the underlying epithelial cells. This protective mechanism ensures that the stomach's digestive processes can occur efficiently without causing harm to its own tissues.