The many projections on the wall of small intestine function to -

Options

A. Secrete digestion enzymes
B. Increase the surface area
C. Hold products of digestion so they do not enter the large intestine
D. Hold mucus, so ulcers do not form

Answer

**Step-by-Step Solution:**

1. **Identify the Structure**: The question refers to the many projections on the wall of the small intestine, which are known as villi.

2. **Understand the Composition**: The wall of the small intestine consists of several layers, with the innermost layer being called the mucosa. The mucosa is responsible for the formation of these projections.

3. **Function of Villi**: The primary function of the villi is to increase the surface area of the small intestine. This increased surface area is crucial for the absorption of nutrients from digested food.

4. **Mechanism of Absorption**: By having a larger surface area due to the presence of villi, the small intestine can effectively absorb more nutrients and digestive products into the bloodstream.

5. **Conclusion**: Therefore, the many projections (villi) on the wall of the small intestine serve to increase the surface area, facilitating better absorption of nutrients.

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