Spleen

An organ located in the upper left part of the abdomen near the stomach. The spleen produces lymphocytes; it is the largest lymphatic organ in the body. The spleen also filters the blood, serves as a major reservoir for blood and destroys blood cells that are aged.

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A large vascular lymphatic organ lying in the upper part of the abdominal cavity on the left side, between the stomach and diaphragm, composed of white and red pulp; the white consists of lymphatic nodules and diffuse lymphatic tissue; the red consists of venous sinusoids between which are splenic cords; the stroma of both red and white pulp is reticular fibers and cells. A framework of fibroelastic trabeculae extending from the capsule subdivides the structure into poorly defined lobules. It is a blood-forming organ in early life and later a storage organ for red corpuscles and platelets; because of the large number of macrophages, it also acts as a blood filter, both identifying and destroying effete erythrocytes. SYN: splen [TA], lien. [G. splen]

- accessory s. [TA] one of the small globular masses of splenic tissue occasionally found in the region of the s., in one of the peritoneal folds or elsewhere. SYN: splen accessorius [TA], lien accessorius, lien succenturiatus, lienculus, lienunculus, spleneolus, spleniculus, splenule, splenulus, splenunculus.

- diffuse waxy s. a condition of amyloid degeneration of the s., affecting chiefly the extrasinusoidal tissue spaces of the pulp.

- floating s. a s. that is palpable because of excessive mobility from a relaxed or lengthened pedicle rather than because of enlargement. SYN: lien mobilis, movable s..

- lardaceous s. SYN: waxy s..

- movable s. SYN: floating s..

- sago s. amyloidosis in the s. affecting chiefly the malpighian bodies.

- sugar-coated s. hyaloserositis involving the s..

- waxy s. amyloidosis of the s.. SYN: lardaceous s..

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spleen 'splēn n a highly vascular ductless abdominal organ of vertebrates that resembles a gland in organization but is closely associated with the circulatory system, that plays a role in the final destruction of red blood cells, filtration and storage of blood, and production of lymphocytes, and that in humans is a dark purplish flattened oblong object of a soft fragile consistency lying near the cardiac end of the stomach and consisting largely of blood and lymphoid tissue enclosed in a fibroelastic capsule from which trabeculae ramify through the tissue of the organ which is divisible into a loose friable red pulp in intimate connection with the blood supply and with red blood cells free in its interstices and a denser white pulp chiefly of lymphoid tissue condensed in masses about the small arteries

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n.

a large dark-red ovoid organ situated on the left side of the body below and behind the stomach. It is enclosed within a fibrous capsule that extends into the spongy interior - the splenic pulp - to form a supportive framework. The pulp consists of aggregates of lymphoid tissue (white pulp) within a meshwork of reticular fibres packed with red blood cells (red pulp). The spleen is a major component of the reticuloendothelial system, producing lymphocytes in the newborn and containing phagocyte, which remove worn-out red blood cells and other foreign bodies from the bloodstream. It also acts as a reservoir for blood and, in the fetus, as a source of red blood cells. Anatomical name: lien.

• splenic adj.

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(splēn) [Gr. splēn; L. splen] 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; it has a flattened oblong shape and is about 125 mm long, the largest structure in the lymphoid system. It has a purple color and a pliable consistency, and is distinguished by two types of tissue: red pulp and white pulp, named for their appearance on the cut surface of the organ. The spleen disintegrates red blood cells and sets free hemoglobin, which the liver converts into bilirubin; it serves as a reservoir of blood; and it produces lymphocytes and plasma cells. During fetal life and in the newborn it gives rise to new red blood cells. It has other important functions whose full scope has not been entirely determined. Called also splen [TA] and lien [TA alternative]. splenic adj

Spleen; visceral surface.