Which of the following is not associated with the innermost mucosa layer of the small intestine ?

Options

A. Goblet cells
B. Brunner gland
C. Crypts of Lieberkuhn
D. Villi and microvilli

Answer

To solve the question of which component is not associated with the innermost mucosal layer of the small intestine, we will analyze each of the given options step by step.

### Step-by-Step Solution:

1. **Understanding the Mucosal Layer**:
- The innermost layer of the small intestine is called the mucosa. It is responsible for the secretion of digestive enzymes and absorption of nutrients.

2. **Analyzing Goblet Cells**:
- Goblet cells are specialized epithelial cells that produce mucus. They are indeed found in the mucosal layer of the small intestine.
- **Conclusion**: Goblet cells are associated with the mucosal layer.

3. **Analyzing Brunner's Glands**:
- Brunner's glands are located in the submucosa of the duodenum. They secrete alkaline mucus to protect the intestinal lining and neutralize gastric acid.
- **Conclusion**: Brunner's glands are NOT associated with the innermost mucosal layer, as they are located in the submucosa.

4. **Analyzing Crypts of Lieberkühn**:
- Crypts of Lieberkühn are glandular structures located in the mucosal layer of the small intestine. They contain cells that secrete intestinal juices.
- **Conclusion**: Crypts of Lieberkühn are associated with the mucosal layer.

5. **Analyzing Villi and Microvilli**:
- Villi are finger-like projections that increase the surface area for absorption and are part of the mucosal layer. Microvilli are tiny projections on the surface of epithelial cells of the villi, further increasing surface area.
- **Conclusion**: Villi and microvilli are associated with the mucosal layer.

### Final Answer:
The component that is NOT associated with the innermost mucosal layer of the small intestine is **Brunner's glands**.