In which part of the intestine does absorption primarily begin?

The duodenum is the section of the small intestine where absorption primarily begins after the stomach. When chyme, which is the semi-liquid mass of partly digested food, enters the duodenum from the stomach, it is mixed with bile from the liver and pancreatic juices. These secretions contain enzymes that further digest the food, making nutrients available for absorption.

The lining of the duodenum is equipped with numerous villi and microvilli, which increase the surface area for absorption. While the process of nutrient absorption continues in other parts of the small intestine, such as the jejunum and ileum, the initial breakdown and absorption of the digestive contents are primarily initiated in the duodenum. The role of the duodenum is critical in ensuring that the nutrients can be effectively absorbed into the bloodstream as they move through the digestive system.