Jejunum vs. Ileum

Main Difference

The main difference between Jejunum and Ileum is that the Jejunum is a part of small intestine and Ileum is a The final section of the small intestine in mammals, reptiles, birds and some other vertebrates

• Jejunum

  The jejunum is the second part of the small intestine in humans and most higher vertebrates, including mammals, reptiles, and birds. Its lining is specialized for the absorption by enterocytes of small nutrient molecules which have been previously digested by enzymes in the duodenum.

  The jejunum lies between the duodenum and the ileum and is considered to start at the suspensory muscle of the duodenum, a location called the duodenojejunal flexure. The division between the jejunum and ileum is not anatomically distinct. In adult humans, the small intestine is usually 6–7 metres (20–23 ft) long (post mortem), about two-fifths of which (about 2.5 m (8.2 ft)) is the jejunum.

• Ileum

  The ileum is the final section of the small intestine in most higher vertebrates, including mammals, reptiles, and birds. In fish, the divisions of the small intestine are not as clear and the terms posterior intestine or distal intestine may be used instead of ileum.

  The ileum follows the duodenum and jejunum and is separated from the cecum by the ileocecal valve (ICV). In humans, the ileum is about 2–4 m long, and the pH is usually between 7 and 8 (neutral or slightly alkaline).

  Ileum is derived from the Greek word eilein, meaning “to twist up tightly.”

• Ileum (noun)

  the third portion of the small intestine, between the jejunum and the caecum.