Crypts of Lieberkühn
Encyclopedia
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 secrete various enzymes, including sucrase
and maltase
, along with enteropeptidase
.
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.
Loss of proliferation control in the crypts is thought to lead to colorectal cancer
.
Causes of crypt branching include:
Crypt inflammation
is known as cryptitis
and characterized by the presence of neutrophils between the enterocyte
s. A severe cryptitis may lead to a crypt abscess
.
.
Histology
Histology is the study of the microscopic anatomy of cells and tissues of plants and animals. It is performed by examining cells and tissues commonly by sectioning and staining; followed by examination under a light microscope or electron microscope...
, an intestinal crypt (also crypt of Lieberkühn and intestinal gland) is a gland
Gland
A gland is an organ in an animal's body that synthesizes a substance for release of substances such as hormones or breast milk, often into the bloodstream or into cavities inside the body or its outer surface .- Types :...
found in the epithelial lining of the small intestine
Small intestine
The small intestine is the part of the gastrointestinal tract following the stomach and followed by the large intestine, and is where much of the digestion and absorption of food takes place. In invertebrates such as worms, the terms "gastrointestinal tract" and "large intestine" are often used to...
and colon
Colon (anatomy)
The colon is the last part of the digestive system in most vertebrates; it extracts water and salt from solid wastes before they are eliminated from the body, and is the site in which flora-aided fermentation of unabsorbed material occurs. Unlike the small intestine, the colon does not play a...
. The crypts secrete various enzymes, including sucrase
Sucrase
Sucrase is the name given to a number of enzymes that catalyze the hydrolysis of sucrose to fructose and glucose. The enzyme invertase, which occurs more commonly in plants, also hydrolyzes sucrose but by a different mechanism.-Physiology:...
and maltase
Maltase
Maltase is an enzyme that breaks down the disaccharide maltose. Maltase is an enzyme that catalyzes the hydrolysis of the disaccharide maltose to the simple sugar glucose. This enzyme is found in plants, bacteria, and yeast. Then there is what is called Acid maltase deficiency...
, along with enteropeptidase
Enteropeptidase
Enteropeptidase is an enzyme produced by cells of the duodenum and involved in human digestion. It is secreted from intestinal glands following the entry of ingested food passing from the stomach...
.
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
Lumen (anatomy)
A lumen in biology is the inside space of a tubular structure, such as an artery or intestine...
) portion of the crypt contains multipotent stem cells. During each mitosis
Mitosis
Mitosis is the process by which a eukaryotic cell separates the chromosomes in its cell nucleus into two identical sets, in two separate nuclei. It is generally followed immediately by cytokinesis, which divides the nuclei, cytoplasm, organelles and cell membrane into two cells containing roughly...
, 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
Intestinal epithelial differentiation genes
Table of genes implicated in development and differentiation of the intestinal epithelium The table listed below is a running comprehensive list of all intestinal differential genes that have been reported in the literature. The PMID is the pubmed identification number of the papers that support...
have been shown to be important for the differentiation of intestinal stem cells.
Loss of proliferation control in the crypts is thought to lead to colorectal cancer
Colorectal cancer
Colorectal cancer, commonly known as bowel cancer, is a cancer caused by uncontrolled cell growth , in the colon, rectum, or vermiform appendix. Colorectal cancer is clinically distinct from anal cancer, which affects the anus....
.
Pathologic changes
Pathologic processes that lead to chronic, i.e. on-going, intestinal crypt destruction are associated with branching of the crypts.Causes of crypt branching include:
- inflammatory bowel diseaseInflammatory bowel diseaseIn medicine, inflammatory bowel disease is a group of inflammatory conditions of the colon and small intestine. The major types of IBD are Crohn's disease and ulcerative colitis.-Classification:...
(e.g. ulcerative colitisUlcerative colitisUlcerative colitis is a form of inflammatory bowel disease . Ulcerative colitis is a form of colitis, a disease of the colon , that includes characteristic ulcers, or open sores. The main symptom of active disease is usually constant diarrhea mixed with blood, of gradual onset...
, Crohn's diseaseCrohn's diseaseCrohn's disease, also known as regional enteritis, is a type of inflammatory bowel disease that may affect any part of the gastrointestinal tract from mouth to anus, causing a wide variety of symptoms...
), - persistent infectious colitides, and
- ischemic colitisIschemic colitisIschemic colitis is a medical condition in which inflammation and injury of the large intestine result from inadequate blood supply. Although uncommon in the general population, ischemic colitis occurs with greater frequency in the elderly, and is the most common form of bowel ischemia...
.
Crypt inflammation
Inflammation
Inflammation is part of the complex biological response of vascular tissues to harmful stimuli, such as pathogens, damaged cells, or irritants. Inflammation is a protective attempt by the organism to remove the injurious stimuli and to initiate the healing process...
is known as cryptitis
Cryptitis
In histology, cryptitis refers to inflammation of an intestinal crypt.Cryptitis is a non-specific histopathologic finding that is seen in several conditions, e.g. inflammatory bowel disease, diverticular disease, radiation colitis, infectious colitis....
and characterized by the presence of neutrophils between the enterocyte
Enterocyte
Enterocytes, or intestinal absorptive cells, are simple columnar epithelial cells found in the small intestines and colon. A glycocalyx surface coat contains digestive enzymes. Microvilli on the apical surface increase surface area for the digestion and transport of molecules from the intestinal...
s. A severe cryptitis may lead to a crypt abscess
Abscess
An abscess is a collection of pus that has accumulated in a cavity formed by the tissue in which the pus resides due to an infectious process or other foreign materials...
.
Eponym
The eponymous term (crypts of Lieberkühn) is named after the 18th-century German anatomist Johann Nathanael LieberkühnJohann Nathanael Lieberkühn
Johann Nathanael Lieberkühn was a German physician. His middle name is sometimes misspelled Nathaniel....
.
