Spleen
The spleen is an organ in vertebrates. The spleen is part of the lymphatic system. In people, it is on the left side of the body, under the heart. The spleen helps fight infections and keeps the blood cells healthy.
Tasks
The spleen cleans out old blood cells from the blood and recycles them. It helps save the iron and the amino acids from the old blood cells. The spleen also holds a supply of extra blood, in case the body needs some quickly. The spleen works together with the circulatory system (the system which brings blood to the body).
A study published in 2009 using mice found that the spleen is a reservoir which holds over half the body's monocytes.[1] These monocytes move to injured tissue (such as the heart after myocardial infarction), turn into dendritic cells and macrophages, and promote tissue healing.[1][2][3] The spleen is rather like a large lymph node. Its absence makes certain infections more likely.[4]
Shape
The spleen is shaped like a loose fist. It is tucked under the left side of the diaphragm, close by the heart.The average adult spleen weighs 0.44 lbs.
Disease
The spleen can get bigger when a person is digesting food or is sick. If a person's spleen gets big enough, it can break open. If this happens, the person needs medical care right away. Emergency surgery might be needed to control the bleeding.
Some of the diseases that cause the spleen to get bigger are:
- malaria,
- rheumatoid arthritis,
- systemic lupus,
- sickle cell anemia,
- leukemia,
- lymphoma, and
- mononucleosis ("mono").
Culture
In the past, many people believed the spleen helped control emotions. For example, if a person was upset or angry, people would think it was because of a spleen problem.
Spleen Media
A 3D medical animation still of spleen structure & exact location
Visceral surface of the spleen
Micrograph of splenic tissue showing the red pulp (red), white pulp (blue) and a thickened inflamed capsule (mostly pink – top of image). H&E stain.
The spleen contains two different tissues, white pulp (A) and red pulp (B). The white pulp functions in producing and growing immune and blood cells. The red pulp functions in filtering blood of antigens, microorganisms, and defective or worn-out red blood cells.
Laparoscopic view of a horse's spleen (the purple and grey mottled organ)
Spleen seen on abdominal ultrasonography
Maximum length of spleen on abdominal ultrasonography
Back of lumbar region, showing surface markings for kidneys, ureters, and spleen
Side of thorax, showing surface markings for bones, lungs (purple), pleura (blue), and spleen (green)
References
- ↑ 1.0 1.1 Swirski F.K. et al 2009. (2009). "Identification of splenic reservoir monocytes and their deployment to inflammatory sites". Science. 325 (5940): 612–6. Bibcode:2009Sci...325..612S. doi:10.1126/science.1175202. PMC 2803111. PMID 19644120.
- ↑ Jia T. & Pamer E.G. 2009. (2009). "Immunology: dispensable but not irrelevant". Science. 325 (5940): 549–50. doi:10.1126/science.1178329. PMC 2917045. PMID 19644100.
- ↑ Finally, the spleen gets some respect Angier, Natalie The New York Times, August 3, 2009.
- ↑ Brender, Erin 2005 (2005). "Spleen patient page" (PDF). Journal of the American Medical Association. American Medical Association. 294 (20): 2660. doi:10.1001/jama.294.20.2660. PMID 16304080. Retrieved 2008-03-20.