Structure and Functions of Spleen
Definition
o The largest lymph organ in the body
o Formed by reticular and lymphatic tissue
Situation
o Left hypochondrium
o Purple
o 12 x 6 x 2 cm
o 200g
Organs associated with the spleen
o Superiorly and posteriorly _ diaphragm
o Inferiorly - left colic flexure of the large intestine
o Anteriorly - fundus of stomach
o Medially - pancreas and the left kidney
o Laterally - separated from the 9th , 10th and 11th ribs and the intercostal muscles by the diaphragm
Structure
o Oval
o Hilum on the lower medial border
o Anterior surface covered by peritoneum
o Fibroelastic capsule
o The capsule dips into the spleen forming trabeculae
o Splenic pulp - red pulp and white pulp
o Red pulp filled with blood
o White pulp consists of areas of lymphatic tissue and blood vessels covered by lymphocytes and macrophages around blood vessels
Hilum
o The structures entering and leaving the spleen at the hilum are :
o Splenic artery
o Splenic vein
o Lymph vessels efferent only
o Nerves
Functions
o Phagocytosis
o Destruction of old and abnormal erythrocytes
o Leukocytes platelets and microbes, are phagocytosed in the spleen
o Development of lymphocytes
o B and T lymphocytes multiply and become immunocompetent in the spleen
o Some B lymphocytes develop into plasma cells and produce antibodies
o Erythropoiesis
