accessory spleen

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spleen

 [splēn]
a large glandlike but ductless organ in the upper part of the abdominal cavity on the left side, lateral to the cardiac end of the stomach. Called also lien. adj., adj splen´ic. It is the largest collection of reticuloendothelial cells in the body and is composed of spongelike tissue of two types: red pulp, which is the dark reddish brown substance filling the interspaces of the sinuses of the spleen, and white pulp, which consists of sheaths of lymphatic tissue surrounding the arteries of the spleen. It is enclosed in a dense capsule. In a normal adult the spleen is about 12.5 cm long and weighs about 140 to 210 g. After gastric digestion and in the presence of disease the spleen enlarges.



During fetal life the spleen and liver produce erythrocytes, but after birth that function is taken over by the bone marrow. However, if there is bone marrow failure, the spleen may again produce erythrocytes. In the normal adult the spleen is a reservoir for blood, and contains a high concentration of erythrocytes. In times of exertion, emotional stress, pregnancy, severe bleeding, carbon monoxide poisoning, or other occasions when the oxygen content of the blood must be increased, the spleen contracts rhythmically to release its store of erythrocytes into the bloodstream.

The spleen also acts to help keep the blood free of unwanted substances, including wastes and infecting organisms. The blood is delivered to it by the splenic artery, and passes through smaller branch arteries into a network of channels lined with leukocytes known as phagocytes (see reticuloendothelial system). These clear the blood of old erythrocytes, damaged cells, parasites, and other toxic or foreign substances. Hemoglobin from the removed red cells is temporarily stored.
accessory spleen a small mass of tissue elsewhere in the body, histologically and functionally identical with that composing the normal spleen.

ac·ces·so·ry spleen

[TA]
one of the small globular masses of splenic tissue occasionally found in the region of the spleen, in one of the peritoneal folds or elsewhere.

accessory spleen

splen accessorius Any of a number of small aggregates or masses of encapsulated splenic tissue located adjacent to the spleen or along the gastrosplenic ligament. See Spleen.

ac·ces·so·ry spleen

(ak-ses'ŏr-ē splēn) [TA]
One of the small globular masses of splenic tissue occasionally found in the region of the spleen, in one of the peritoneal folds, or elsewhere.
Synonym(s): lien accessorius.
References in periodicals archive ?
Accessory spleens are the most common of all splenic anomalies.
Splenunculi (accessory spleens) were noted and excised from 3 patients in this series (6%).
The embryonic development of accessory spleens can be understood by taking into account the following five phases of splenic development: (1) The manner of formation of the major spleen with its notches and lobulations from separate splenic masses originating on the left side of the dorsal mesogastrium; (2) The formation of an accessory spleen by failure of fusion of splenic anlagen (Failure of fusion of the mesenchymal buds in the dorsal mesogastrium during the 5th week of fetal life).
Splenules, or accessory spleens, are congenital foci of normal splenic tissue that are separate from the main body of the spleen.
It is estimated that accessory spleens exist in 10% of the general population; 15%-20% of the accessory spleens are located in the tail of the pancreas due to entrapment of splenic tissue in the dorsal pancreatic bud during embryologic development.
The accessory spleens may be found in 10% of the population [9], more frequently in women, usually with less than 4 cm in size and located near the splenic hilum or near the pancreatic tail (Figure 3).
Accessory spleens result from the failure in the fifth week of foetal life of groups of mesodermal cells in the dorsal mesogastrum [1].
Like other solid organs laparoscopy procedures, it possesses specific technical challenges.2 Some of these challenges are lack of tactile feedback,10 difficult assessment of accessory spleens,10,11 use of harmonic scalpel and endostapler10 and laparoscopic control of bleeding, and finally the removal of spleen.
An abdominal exploration was done to identify the accessory spleens near the hilum of the spleen, lesser sac, gastrolienal ligament and greater omentum, (Fig.
Accessory spleens in or at the tail of the pancreas: a survey of 2,700 additional necropsies.