Small intestine
The length of the small intestine can vary greatly, from as short as to as long as , also depending on the measuring technique used. The typical length in a living person is 3m-5m. The length depends both on how tall the person is and how the length is measured. Taller people generally have a longer small intestine and measurements are generally longer after death and when the bowel is empty.
Mesentery
The mesentery of the small intestine arises from the root of the mesentery (or mesenteric root) and is the part connected with the structures in front of the vertebral column. The root is narrow, about 15 cm long, 20 cm in width, and is directed obliquely from the duodenojejunal flexure at the left side of the second lumbar vertebra to the right sacroiliac joint. The root of the mesentery extends from the duodenojejunal flexure to the ileocaecal junction. This section of the small intestine is located centrally in the abdominal cavity and lies behind the transverse colon and the greater omentum.