What is the primary function of the folds and villi in the small intestine?

• A. To secrete digestive enzymes
• B. To transport waste materials to the large intestine
• C. To protect the intestinal lining from pathogens
• D. To increase the surface area for nutrient absorption

Answer: (D)

Verified step by step guidance

1. Understand the structure of the small intestine: The small intestine is a long, coiled organ where most of the digestion and absorption of nutrients occurs.
2. Identify the features of the small intestine: The inner surface of the small intestine is lined with folds, villi, and microvilli, which are small, finger-like projections.
3. Recognize the role of folds and villi: These structures significantly increase the surface area of the intestinal lining, allowing for more efficient absorption of nutrients.
4. Consider the function of increased surface area: By having a larger surface area, the small intestine can absorb more nutrients from the digested food as it passes through.
5. Conclude the primary function: The primary function of the folds and villi in the small intestine is to increase the surface area for nutrient absorption, enhancing the efficiency of the digestive process.