The HCI of gastric juice is produced by

Options

A. Chief cells
B. Oxyntic cells
C. Goblet cells
D. Columnar cells

Answer

**Step-by-Step Solution:**

1. **Understanding the Components of Gastric Juice**: Gastric juice is a digestive fluid produced in the stomach, primarily composed of hydrochloric acid (HCl), pepsinogen, and mucus.

2. **Identifying the Cell Types**: There are several types of cells in the gastric mucosa, including:
- Chief cells: Secrete pepsinogen.
- Parietal cells (also known as oxyntic cells): Secrete hydrochloric acid (HCl).
- Goblet cells: Secrete mucus.
- Columnar cells: Provide protection.

3. **Examining Each Cell Type**:
- **Chief Cells**: These cells produce pepsinogen, which is an inactive enzyme that gets converted to pepsin in the presence of HCl. Therefore, they do not produce HCl.
- **Parietal Cells (Oxyntic Cells)**: These cells are responsible for the secretion of HCl. They generate H+ ions through a reaction involving water (H2O) and carbon dioxide (CO2) that forms carbonic acid (H2CO3), catalyzed by the enzyme carbonic anhydrase.
- **Goblet Cells**: Their function is to secrete mucus, which protects the stomach lining but does not produce HCl.
- **Columnar Cells**: These cells primarily serve a protective role and do not secrete HCl or any digestive enzymes.

4. **Conclusion**: The hydrochloric acid (HCl) in gastric juice is produced by the parietal cells (also known as oxyntic cells). This acid is crucial for digestion as it lowers the pH of the stomach, activates pepsinogen to pepsin, and helps kill bacteria.

**Final Answer**: The HCl of gastric juice is produced by parietal cells (oxyntic cells).

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