Ileocecal valve
Encyclopedia
The ileocecal valve, or ileocaecal valve, is of a bilabial papilla structure with physiological sphincter muscle situated at the junction of the small intestine
(ileum) and the large intestine
, with recent evidence indicating an anatomical sphincter may also be present in humans) Its critical function is to limit the reflux of colonic contents into the ileum.
The ileocecal valve is distinctive because it is the only site in the GI tract which is used for Vitamin B12
and bile acid
absorption.
Functionally, roughly two litres of fluid enters the colon daily through the ileocecal valve.
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, which is the smooth muscle
tissue found beneath the mucosal layer of the digestive tract. A thickening of the muscularis externa
is also noted.
There is also a variable amount of lymphatic tissue found at the valve.
, the ileocecal valve is used, along with the appendiceal orifice
, in the identification of the cecum
. This is important, as it indicates that a complete colonoscopy has been performed. The ileocecal valve is typically located on the last fold before entry into the cecum, and can be located from the direction of curvature of the appendiceal orifice, in what is known as the bow and arrow sign
.
Intubation of the ileocecal valve is typically performed in colonoscopy to evaluate the distal, or lowest part of the ileum
. Small bowel endoscopy can also be performed by double-balloon enteroscopy
through intubation of the ileocecal valve.
physician Nicolaes Tulp
(1593–1674), and thus it is sometimes known as Tulp's valve.
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...
(ileum) and the large intestine
Large intestine
The large intestine is the third-to-last part of the digestive system — — in vertebrate animals. Its function is to absorb water from the remaining indigestible food matter, and then to pass useless waste material from the body...
, with recent evidence indicating an anatomical sphincter may also be present in humans) Its critical function is to limit the reflux of colonic contents into the ileum.
The ileocecal valve is distinctive because it is the only site in the GI tract which is used for Vitamin B12
Vitamin B12
Vitamin B12, vitamin B12 or vitamin B-12, also called cobalamin, is a water-soluble vitamin with a key role in the normal functioning of the brain and nervous system, and for the formation of blood. It is one of the eight B vitamins...
and bile acid
Bile acid
Bile acids are steroid acids found predominantly in the bile of mammals. Bile salts are bile acids compounded with a cation, usually sodium. In humans, the salts of taurocholic acid and glycocholic acid represent approximately eighty percent of all bile salts. The two major bile acids are cholic...
absorption.
Functionally, roughly two litres of fluid enters the colon daily through the ileocecal valve.
Histology
The histologyHistology
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...
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, which is the smooth muscle
Smooth muscle
Smooth muscle is an involuntary non-striated muscle. It is divided into two sub-groups; the single-unit and multiunit smooth muscle. Within single-unit smooth muscle tissues, the autonomic nervous system innervates a single cell within a sheet or bundle and the action potential is propagated by...
tissue found beneath the mucosal layer of the digestive tract. A thickening of the muscularis externa
Muscularis externa
The muscular coat is a region of muscle in many organs in the vertebrate body, adjacent to the submucosa membrane...
is also noted.
There is also a variable amount of lymphatic tissue found at the valve.
Clinical significance
During colonoscopyColonoscopy
Colonoscopy is the endoscopic examination of the large bowel and the distal part of the small bowel with a CCD camera or a fiber optic camera on a flexible tube passed through the anus. It may provide a visual diagnosis and grants the opportunity for biopsy or removal of suspected...
, the ileocecal valve is used, along with the appendiceal orifice
Vermiform appendix
The appendix is a blind-ended tube connected to the cecum , from which it develops embryologically. The cecum is a pouchlike structure of the colon...
, in the identification of the cecum
Cecum
The cecum or caecum is a pouch, connecting the ileum with the ascending colon of the large intestine. It is separated from the ileum by the ileocecal valve or Bauhin's valve, and is considered to be the beginning of the large intestine. It is also separated from the colon by the cecocolic...
. This is important, as it indicates that a complete colonoscopy has been performed. The ileocecal valve is typically located on the last fold before entry into the cecum, and can be located from the direction of curvature of the appendiceal orifice, in what is known as the bow and arrow sign
Bow and arrow sign
The bow and arrow sign is an endoscopic sign for determining the location of the ileocecal valve during colonoscopy. Identifying the ileocecal valve in a colonoscopy is important, as it indicates that the entire colon has been visualized....
.
Intubation of the ileocecal valve is typically performed in colonoscopy to evaluate the distal, or lowest part of the ileum
Ileum
The ileum 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.The ileum follows the duodenum...
. Small bowel endoscopy can also be performed by double-balloon enteroscopy
Double-balloon enteroscopy
Double-balloon enteroscopy, also known as push-and-pull enteroscopy is an endoscopic technique for visualization of the small bowel. It was developed by Hironori Yamamoto in 2001...
through intubation of the ileocecal valve.
Etymology
It was described by the DutchNetherlands
The Netherlands is a constituent country of the Kingdom of the Netherlands, located mainly in North-West Europe and with several islands in the Caribbean. Mainland Netherlands borders the North Sea to the north and west, Belgium to the south, and Germany to the east, and shares maritime borders...
physician Nicolaes Tulp
Nicolaes Tulp
Nicolaes Tulp was a Dutch surgeon and mayor of Amsterdam. Tulp was well known for his upstanding moral character.-Life:...
(1593–1674), and thus it is sometimes known as Tulp's valve.
