In which part of the digestive system does most nutrient absorption occur?

Most nutrient absorption occurs in the small intestine, which is specifically designed for this function. The small intestine consists of three segments: the duodenum, jejunum, and ileum. Its inner surface is lined with villi and microvilli, which greatly increase the surface area available for absorption. Nutrients from digested food, such as amino acids, fatty acids, and simple sugars, are absorbed through the walls of the small intestine and into the bloodstream.

The large intestine primarily focuses on the absorption of water and electrolytes, rather than nutrients. The stomach mainly breaks down food through mechanical and chemical means, but most nutrient absorption does not take place there; it primarily aids in digestion. The esophagus serves as a conduit for food to travel from the mouth to the stomach and does not play a role in nutrient absorption. Thus, the small intestine is the key player in the process of nutrient absorption in the digestive system.