What are the structures of the human's main small intestine?

The main function of the small intestine is absorption of the nutrients and minerals in the food ingested, usually via the mouth, at an earlier stage in the digestive ... Briefly, the inside surfaces of small intestine have many folds called plicae circulares, from which project many tiny finger-like structures of tissue called villi. read more

The small intestine or small bowel is the part of the gastrointestinal tract between the stomach and the large intestine, and is where most of the end absorption of food takes place. The small intestine has three distinct regions – the duodenum, jejunum, and ileum. read more

The internal walls of the small intestine are covered in finger-like tissue called villi. Each of these villi is covered in even smaller finger-like structures called microvilli. These villi and microvilli increase the surface area available for the absorption of nutrients. read more