What are the three main sections of the small intestine?

The three main sections of the small intestine are indeed the duodenum, jejunum, and ileum. The small intestine plays a critical role in digestion and nutrient absorption, and each of its sections has specific functions.

The duodenum is the first segment and is responsible for the initial digestion of food. It receives chyme from the stomach and bile from the liver, which helps in the emulsification of fats, as well as pancreatic juices that contain digestive enzymes.

Following the duodenum, the jejunum is the middle section where a significant portion of nutrient absorption occurs. The jejunum's lining has numerous folds and villi, which increase the surface area for absorbing carbohydrates, proteins, and lipids, making it highly efficient in nutrient uptake.

The ileum is the final section of the small intestine, which continues the process of nutrient absorption, especially important for absorbing vitamin B12 and bile salts. The ileum also connects to the large intestine at the cecum, marking the end of the small intestine's role in the digestive process.

The other options represent incorrect combinations of intestinal sections or include parts of the digestive system that are not part of the small intestine, such as the colon and gastric section, which are associated with the large