What major organ is responsible for nutrient absorption?

The small intestine is the major organ responsible for nutrient absorption in the digestive system. This is primarily due to its specialized structure, which includes a large surface area provided by villi and microvilli. These tiny projections increase the surface area available for absorption, allowing for a more efficient uptake of nutrients from digested food.

As food moves through the small intestine, enzymes break down carbohydrates, proteins, and fats into absorbable molecules such as sugars, amino acids, and fatty acids. The lining of the small intestine contains cells designed to transport these nutrients into the bloodstream, where they can be delivered to various tissues and organs throughout the body for use in various metabolic processes.

In contrast, the large intestine's primary functions are water absorption and the formation of feces, while the stomach plays a crucial role in the mechanical and chemical breakdown of food, but nutrient absorption primarily occurs in the small intestine. The liver, although essential in processing nutrients and filtering blood, is not directly involved in the absorption process itself, making the small intestine the clear answer to the question regarding the organ responsible for nutrient absorption.