Intestinal gland
| Intestinal gland | |
|---|---|
| Micrograph of the small intestine mucosa showing the crypts of Lieberkühn - bottom 1/3 of image. H&E stain. | |
| Latin | glandulae intestinales |
| Gray's | subject #248 1174 |
In histology, an intestinal crypt (also crypt of Lieberkühn and intestinal gland) is a gland found in the epithelial lining of the small intestine and colon. The crypts and intestinal villi are covered by epithelium which contains two types of cells, goblet cells (secreting mucus) and enterocytes (absorbing water and electrolytes).
The enterocytes in the mucosa contain digestive enzymes that digest specific food while they are being absorbed through the epithelium. These enzymes include peptidases, sucrase, maltase, lactase and intestinal lipase. This is in contrast to the stomach where chief cells secrete pepsinogen, in the intestine the aforementioned digestive enzymes are not secreted by the cells of the intestine.
Also, new epithelium is formed here, which is important because the cells at this site are continuously worn away by the passing food. The basal (further from the intestinal lumen) portion of the crypt contains multipotent stem cells. During each mitosis, one of the two daughter cells remains in the crypt as a stem cell, while the other differentiates and migrates up the side of the crypt and eventually into the villus. Goblet cells are among the cells produced in this fashion. Many genes have been shown to be important for the differentiation of intestinal stem cells.[clarification needed]
Loss of proliferation control in the crypts is thought to lead to colorectal cancer.
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Pathologic changes [edit]
Pathologic processes that lead to crohn's, i.e. on-going, intestinal crypt destruction are associated with branching of the crypts.
Causes of crypt branching include:
- inflammatory bowel disease (e.g. ulcerative colitis, Crohn's disease),
- persistent infectious colitides, and
- ischemic colitis.
Crypt inflammation is known as cryptitis and characterized by the presence of neutrophils between the enterocytes. A severe cryptitis may lead to a crypt abscess.
Eponym [edit]
The eponymous term (crypts of Lieberkühn) is named after the 18th-century German anatomist Johann Nathanael Lieberkühn.
See also [edit]
Additional images [edit]
External links [edit]
- Illustration at trinity.edu
- Illustration at kumc.edu
- Illustration at uokhsc.edu
- synd/2651 at Who Named It?
- intestinal+glands at eMedicine Dictionary
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