Ace the BMAT 2026 – Unleash Your Biomedical Superpowers!

The small intestine plays a crucial role in nutrient absorption primarily through active transport and diffusion. The lining of the small intestine is richly supplied with microvilli, which significantly increase surface area and enhance the absorption capability.

Active transport allows the cells of the intestinal lining to move substances against their concentration gradient, which is essential for absorbing nutrients such as glucose and amino acids. This process requires energy and enables the body to take in nutrients even when their concentration is lower in the intestine compared to the cells.

Diffusion, on the other hand, occurs for substances that can passively move down their concentration gradient, such as the absorption of fats and certain water-soluble vitamins. Both mechanisms are vital for ensuring that the body efficiently extracts and absorbs a wide variety of nutrients from the food consumed.

In contrast, the other responses do not accurately reflect the contributions of the small intestine. While the intestine is involved in waste elimination, this is not a primary function related to nutrient absorption. Bile, secreted by the liver and stored in the gallbladder, aids in the digestion of fats but is not secreted by the small intestine itself, making it irrelevant to nutrient absorption processes happening within it. Thus, the correct answer accurately encapsulates the mechanisms through which