Spleen

Infobox Anatomy
Name = Spleen
Latin = splen, lien
GraySubject = 278
GrayPage = 1282


Caption = Spleen


Caption2 = Laparoscopic view of a horse's spleen (the purple and grey mottled organ)
Precursor = Mesenchyme of dorsal mesogastrium
System =
Artery = Splenic artery
Vein = Splenic vein
Nerve = Splenic plexus
Lymph =
MeshName = Spleen
MeshNumber = A10.549.700
DorlandsPre = s_19
DorlandsSuf = 12750780
The spleen is an organ found in all vertebrate animals. [http://www.daviddarling.info/encyclopedia/S/spleen.html Entry for spleen, Internet Encyclopedia of Science] ] In humans, the spleen is located in the abdomen of the body, where it functions in the destruction of redundant red blood cells and holds a reservoir of blood. It is regarded as one of the centers of activity of the reticuloendothelial system (part of the immune system). It is increasingly recognized that its absence leads to a predisposition to certain infections.cite journal
last = Brender, MD
first = Erin
authorlink = Erin Brender, MD
coauthors = Richard M. Glass, MD, editor
title = Spleen Patient Page
journal = Journal of the American Medical Association
volume = 294
issue = 20
pages = 2660
publisher = American Medical Association
date = 2005-11-23-30
url = http://jama.ama-assn.org/cgi/reprint/294/20/2660.pdf
format = PDF
accessdate = 2008-03-20 ]

Anatomy

The spleen is an organ found in the left upper abdomen above the stomach and underneath the rib cage. Spleens in healthy adults are approximately convert|9|to|13|cm in length. [cite journal | last=Spielmann | first=Audrey L. | coauthors=David M. DeLong, Mark A. Kliewer | title=Sonographic Evaluation of Spleen Size in Tall Healthy Athletes | journal=American Journal of Roentgenology | volume=2005 | issue=184 | pages=45-49 | publisher=American Roentgen Ray Society | url=http://www.ajronline.org/cgi/content/abstract/184/1/45 | accessdate=2008-09-09 ]

Like the thymus, the spleen possesses only efferent lymphatic vessels.

Function

Other functions of the spleen are less prominent, especially in the healthy adult:

* Production of opsonins, properdin, and tuftsin.

* Creation of red blood cells. While the bone marrow is the primary site of hematopoeisis in the adult, the spleen has important hematopoietic functions up until the fifth month of gestation. After birth, erythropoietic functions cease except in some hematologic disorders. As a major lymphoid organ and a central player in the reticuloendothelial system the spleen retains the ability to produce lymphocytes and, as such, remains an hematopoietic organ.

* Storage of red blood cells and other formed elements. This is only valid for certain mammals, such as dogs and horsesFact|date=May 2008. In horses roughly 50% of the red blood cells are stored there. The red blood cells can be released when needed cite news | first=Bjorn | last=Carey | url=http://www.msnbc.msn.com/id/12648465/ | title=Horse science: What makes a Derby winner - Spleen acts as 'natural blood doper,' scientist says | work= MSNBC.com | publisher=Microsoft | date=May 5, 2006 | accessdate=2006-05-09] These animals also have large hearts in relation to their body size to accommodate the higher-viscosity blood that results. In humans, however, the spleen does not function as a depository of red blood cells, but instead it stores platelets in case of an emergency. Some athletes have tried doping themselves with their own stored red blood cells to try to achieve the same effectFact|date=November 2007, but the human heart is not equipped to handle the higher-viscosity blood.

Disorders

Disorders include splenomegaly, where the spleen is enlarged by various reasons. On the other hand, a lack of normal spleen function is called asplenia.

Etymology and cultural views

The word spleen comes from the Greek "splēn". In Latin its name is "lien".

In French, spleen refers to a state of pensive sadness or melancholy. It has been popularized by the poet Charles Baudelaire (1821–1867) but was already used before, in particular in the Romantic literature (18th century). The connection between "spleen" (the organ) and "melancholy" (the temperament) comes from the humoral medicine of the ancient Greeks. One of the humours (body fluid) was the black bile, secreted by the spleen organ and associated with melancholy. In contrast, the Talmud (tractate Berachoth 61b) refers to the spleen as the organ of laughter, possibly suggesting a link with the humoral view of the organ.

In German, the word "Spleen", pronounced "shplehn," refers to a persisting somewhat eccentric (but not quite lunatic) idea or habit of a person; however the organ is called "Milz", (cognate with Old English milte).

In eighteenth- and nineteenth-century England, women in bad humour were said to be afflicted by the spleen, or the vapours of the spleen. In modern English, "to vent one's spleen" means to vent one's anger, e.g. by shouting, and can be applied to both males and females; similarly, the English term "" is used to describe a person in a foul mood.

In China, the spleen ' (pí)' counts as the seat of one's temperament and is thought to influence the individual's willpower. Analogous to "venting one's spleen", "發脾氣" is used as an expression for getting angry, although in the view of Traditional Chinese Medicine, the view of "脾" does not correspond to the anatomical "spleen".

In chiropractic (meric chart) problems with the spleen relate to T8 (eighth thorasic vertebrea), a subluxation at T8 is associated with low energy and/or low immune system function.

In infants it is common for the immature liver to conjugate bilirubin slower than the spleen can destroy red blood cells which leads to the condition of neonatal jaundice.

ee also

* marginal zone

=Additional

Footnotes

External links

* - "The visceral surface of the spleen."
*
* [http://www.britannica.com/eb/article-9069185/spleen "spleen"] from "Encyclopedia Britannica Online"
* [http://www.kidshealth.org/PageManager.jsp?dn=familydoctor&lic=44&cat_id=20091&article_set=20543&ps=104] from "Spleen and Lymphatic System at Family Doctor.org"
* [http://www.nlm.nih.gov/medlineplus/spleendiseases.html] from "Medline Plus Spleen Diseases"