THORAX ABDOMEN AND PELVIS

Detailed explanation-1: -The middle part of the small intestine. It is between the duodenum (first part of the small intestine) and the ileum (last part of the small intestine). The jejunum helps to further digest food coming from the stomach.

Detailed explanation-2: -It is divided into three parts: the duodenum, jejunum and ileum. The beginning portion of the small intestine (the duodenum) begins at the exit of the stomach (pylorus) and curves around the pancreas to end in the region of the left upper part of the abdominal cavity where it joins the jejunum.

Detailed explanation-3: -The jejunum and ileum come from the midgut, whereas the duodenum derives from the foregut. Villi and crypts make up the lining of the small intestine. Originally, the small intestine is lined by cuboidal cells up until the ninth week of gestation; then, villi begin to form.