Ileum

The ileum is the final section of the <a href="/facts/Small_intestine/1AQ8RJ4m">small intestine</a> in most <a href="/facts/Higher_vertebrates/TeLtDTrJ">higher vertebrates</a>, including <a href="/facts/Mammals/phSwTzBo">mammals</a>, <a href="/facts/Reptiles/04n1uKf1">reptiles</a>, and <a href="/facts/Birds/RJF6zwLP">birds</a>. In <a href="/facts/Fish/fln4gH9V">fish</a>, the divisions of the small intestine are not as clear and the terms posterior intestine or distal intestine may be used instead of ileum. Its main function is to absorb <a href="/facts/Vitamin_B12/vCk613gD">vitamin B12</a>, <a href="/facts/Bile_salts/ojTJzf0c">bile salts</a>, and whatever products of digestion that were not absorbed by the <a href="/facts/Jejunum/PU0q1Syr">jejunum</a>.
The ileum follows the <a href="/facts/Duodenum/IAIgHBmq">duodenum</a> and <a href="/facts/Jejunum/PU0q1Syr">jejunum</a> and is separated from the <a href="/facts/Cecum/SysL1JXX">cecum</a> by the <a href="/facts/Ileocecal_valve/gFp1QLwa">ileocecal valve</a> (ICV). In humans, the ileum is about 2–4 m long, and the <a href="/facts/PH/RnSv8D7y">pH</a> is usually between 7 and 8 (neutral or slightly <a href="/facts/Base_(chemistry)/M9wA7qeM">basic</a>).
Ileum is derived from the Greek word εἰλεός (eileós), referring to a medical condition known as <a href="/facts/Ileus/1rMI0juo">ileus</a>.

Ileum open-in-new

Ileum