The Full Wiki

Cecum: Wikis

  

Note: Many of our articles have direct quotes from sources you can cite, within the Wikipedia article! This article doesn't yet, but we're working on it! See more info or our list of citable articles.

Encyclopedia

From Wikipedia, the free encyclopedia

Cecum
Stomach colon rectum diagram.svg
Gray1043.png
Superior ileocecal fossa (cecum labeled at bottom left)
Gray's subject #249 1177
Precursor Midgut
MeSH Cecum
Dorlands/Elsevier Cecum

The cecum or caecum (from the Latin caecus meaning blind) is a pouch, connecting the ileum with the ascending colon of the large intestine. It is separated from the ileum by the ileocecal valve (ICV) 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 junction.

Contents

Variation across species

A cecum is present in most amniote species, and also in lungfish, but not in any living species of amphibian. In reptiles, it is usually a single median structure, arising from the dorsal side of the large intestine. Birds typically have two paired ceca, as, unlike other mammals, do hyraxes.[1]

Most mammalian herbivores have a relatively large caecum, hosting a large number of bacteria, which aid in the enzymatic breakdown of plant materials such as cellulose; in many species, it is considerably wider than the colon. In contrast, obligatory carnivores, whose diets contain little or no plant material, have a reduced cecum, which is often partially or wholly replaced by the vermiform appendix.[1]

Many fish have a number of small outpocketings, called pyloric ceca, along their intestine; despite the name they are not homologous with the cecum of amniotes, and their purpose is to increase the overall area of the digestive epithelium.[1] Some invertebrates, such as squid,[2] may also have structures with the same name, but these have no relationship with those of vertebrates.

Etymology

The term cecum comes from the Latin caecum, literally "blind", here in the sense "blind gut" or "cul de sac".

In dissections by the Greek philosophers, the connection between the ileum of the small intestines and the cecum was not fully understood. Most of the studies of the digestive tract were done on animals and the results were compared to human structures.

The junction between the small intestine and the colon, called the ileocecal valve, is so small in some animals that it was not considered to be a connection between the small and large intestines. During a dissection, the colon could be traced from the rectum, to the sigmoid colon, through the descending, transverse, and ascending sections. The colon seemed to dead-end into the cecum, or cul-de-sac.

The connection between the end of the small intestine (ileum) and the start of the colon (cecum) is now clearly understood, but the name has not changed.

See also

Additional images

References

  1. ^ a b c Romer, Alfred Sherwood; Parsons, Thomas S. (1977). The Vertebrate Body. Philadelphia, PA: Holt-Saunders International. pp. 353-354. ISBN 0-03-910284-X. 
  2. ^ Williams, L.W. (1910), The anatomy of the common squid : Loligo pealii, Lesueur, American Museum Of Natural History 

External links


Simple English

The cecum is a part of the large intestine. It is comes before the colon and after the ileum in the gastrointestinal system. The appendix is connected to the cecum.








Got something to say? Make a comment.
Your name
Your email address
Message