Which organ is primarily responsible for nutrient absorption?

The small intestine is primarily responsible for nutrient absorption due to its specialized structure and extensive surface area. It is lined with tiny, finger-like projections called villi, which increase the surface area available for absorption. Within the small intestine, the breakdown of food continues, and nutrients—including carbohydrates, proteins, fats, vitamins, and minerals—are absorbed into the bloodstream through the walls of the small intestine.

Additionally, the small intestine is divided into three sections: the duodenum, jejunum, and ileum, each contributing to the digestive process and nutrient absorption in a sequential manner. The presence of digestive enzymes and bile helps to further break down food, facilitating the absorption of these essential nutrients.

In contrast, while the stomach plays a role in the initial phase of digestion by breaking down food mechanically and chemically, it is not the primary site for nutrient absorption. The pancreas produces digestive enzymes and hormones that assist in digestion, but it does not absorb nutrients itself. The liver, though vital for metabolism, detoxification, and storage of nutrients, does not have a direct role in the absorption of nutrients; it functions more as a processing and filtering organ after absorption occurs.