Small Intestine

The small intestine is a long, narrow, highly coiled tube — about 6 metres long and 2.5 cm broad in humans — held coiled within the abdominal cavity by sheets of tissue called mesenteries, which also carry its blood vessels, lymph vessels and nerves. It has three successive parts:

• Duodenum: the first part, about 26 cm long and 'U'-shaped, curving toward the left side of the abdominal cavity just below the stomach. Bile juice and pancreatic juice are poured into it.
• Jejunum: the coiled middle portion, about 2.5 metres long, narrower than the duodenum. …