Ileum

Ileum
Small intestine
The cecal fossa. The ileum and cecum are drawn backward and upward.
Details
Precursor	Midgut
Artery	Ileal arteries, ileocolic artery
Vein	Ileal veins
Nerve	Celiac ganglia, vagus[1]
Identifiers
Latin	ileum
MeSH	D007082
TA98	A05.6.04.001
TA2	2959
FMA	7208
Anatomical terminology [edit on Wikidata]

Major parts of the
Gastrointestinal tract
Upper gastrointestinal tract Mouth Pharynx Esophagus Stomach Duodenum
Lower gastrointestinal tract Small intestine Jejunum Ileum Large intestine Cecum Appendix Ascending colon Transverse colon Descending colon Sigmoid colon Rectum Anus
See also Gastrointestinal wall Human digestive system Anatomical terminology Outline of anatomy
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The ileum (/ˈɪliəm/) 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.^[2] Its main function is to absorb vitamin B₁₂, bile salts, and whatever products of digestion that were not absorbed by the jejunum.

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 basic).

Ileum is derived from the Greek word εἰλεός (eileós), referring to a medical condition known as ileus.