Understanding Gastric Glands and Their Secretions

The gastric glands are located in the lining of the stomach and are responsible for producing gastric juice, which aids in digestion. Let's break down what each component does:

Step 1: Identify the Key Secretions

Gastric glands secrete several important substances:

• Hydrochloric acid (HCl): Creates an acidic environment.
• Pepsinogen: Inactive form of the enzyme pepsin.
• Mucus: Protects the stomach lining.
• Renin (in infants): Helps digest milk proteins.

Step 2: Role of Pepsin

Pepsinogen is activated by HCl to become pepsin. Pepsin breaks down proteins into smaller peptides. It is a primary enzyme in gastric juice.

Step 3: Eliminate Incorrect Options

• Amylase: Secreted by salivary glands and pancreas; breaks down carbohydrates. Not produced in gastric glands.
• Trypsin: Secreted by the pancreas; involved in protein digestion in the small intestine. Not produced in gastric glands.

Step 4: Consider Renin

Renin is secreted by gastric glands, but primarily in infants to curdle milk. In adults, pepsin is the main protease.

Final Answer

The gastric glands release pepsin (as pepsinogen) and renin. However, based on standard biological context, pepsin is a major secretion.

Thus, the correct options are:

• pepsin
• renin

Related Topics

Digestive System: The process of breaking down food into nutrients. Includes organs like mouth, stomach, small intestine.

Enzymes: Biological catalysts that speed up digestion. Each enzyme acts on a specific substrate.

Gastric Juice: Mixture secreted by gastric glands, containing HCl, pepsin, mucus, and renin.

Key Formulae and Theory

Activation of Pepsin:

This reaction is catalyzed by HCl.

Protein Digestion by Pepsin:

Role of Renin: Curdles milk casein, making it digestible by pepsin.