Search results
Results from the WOW.Com Content Network
The ileum (/ ˈ ɪ l i əm /) 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 ]
The ileum: The final section of the small intestine. It is about 3 m long, and contains villi similar to the jejunum. It absorbs mainly vitamin B12 and bile acids, as well as any other remaining nutrients. The ileum joins to the cecum of the large intestine at the ileocecal junction. [citation needed]
Intestinal glands are found in the epithelia of the small intestine, namely the duodenum, jejunum, and ileum, and in the large intestine (colon), where they are sometimes called colonic crypts. Intestinal glands of the small intestine contain a base of replicating stem cells , Paneth cells of the innate immune system , and goblet cells , which ...
The cecum receives chyme from the last part of the small intestine, the ileum, and connects to the ascending colon of the large intestine. At this junction there is a sphincter or valve, the ileocecal valve which slows the passage of chyme from the ileum, allowing further digestion. It is also the site of the appendix attachment. [33]
The histology of the ileocecal valve shows an abrupt change from a villous mucosa pattern of the ileum to a more colonic mucosa. A thickening of the muscularis mucosa, [citation needed] which is the smooth muscle tissue found beneath the mucosal layer of the digestive tract.
The gastroileal reflex is stimulated by the presence of food in the stomach and gastric peristalsis. Initiation of the reflex causes peristalsis in the ileum and the opening of the ileocecal valve (which allows the emptying of the ileal contents into the large intestine, or colon). [1]
The mesoappendix is the portion of the mesentery connecting the ileum to the appendix. It may extend to the tip of the appendix. It encloses the appendicular artery and vein, as well as lymphatic vessels, nerves, and often a lymph node. The mesorectum is that part attached to the upper third of the rectum.
From this point, down to the middle of the ileum, they diminish considerably in size. In the lower part of the ileum , they almost entirely disappear; [ 4 ] hence the comparative thinness of this portion of the intestine, as compared with the duodenum and jejunum.