Spleen // Structure of Spleen//Function of Spleen

Spleen is the lymphoid organ . It is also known as graveyard of RBC because all the RBC after completing their life span (120 days) will be destroyed by spleen .

1. Spleen . Represented by Wasim Akram B.Sc nursing Adwika Institute of nursing

2. Contents Introduction Definition Position Structure Functions Blood Supply Nerve Supply

3. INTRODUCTION Spleen is an important lymphoid organ of The Lymphatic System. Spleen is the largest lymphoid organ of our body. Spleen is not that much vital for our survival . If spleen is removed from our body (Splenectomy), our body distributes its work to other organs , especially to the liver. Spleen is average of 12cm long , 7 cm high & 4cm thick. Average weight of adult spleen is 200g.

4. Definition Spleen is a lymphoid organ present in our upper left abdominal cavity attached with stomach and helps in the filtration of blood and produces lymphocytes. POSITION OF SPLEEN : The spleen is located in the upper-left part of the abdomen . It is attached with the stomach backward just beneath the left part of the diaphragm . It’s protected by Rib Cage ( underneath the ninth , tenth & eleventh ribs ).

5. Structure Spleen is the largest lymphatic organ of the body. Surrounded by a connective tissue capsule , which extends inward to divide the organ into lobules . The spleen consists of two types of tissue called White Pulp and Red Pulp . The White Pulp is lymphatic tissue consisting mainly of lymphocytes around arteries and full of lymphoid cells . The white pulp is a highly organized lymphoid region . Here adaptive immune responses can be initiated. It is composed of separate areas for B cells & T cells , which are surrounded by the marginal zone . Marginal zone is a region that contains discrete subsets of macrophages & B cells . Blood flows freely through the marginal zone , the white pulp is excluded from the Bloodstream.

6. Structure The Red Pulp consists of Venous Sinuses filled with blood and Splenic Cords of lymphatic cells , such as lymphocytes & Macrophages and Marginal zone. The sinuses are lined by elongated , rod-shaped endothelial cells . It’s primary function is to filter the blood of Antigens , Microorganisms , and defective or worn-out RBCs (red blood corpuscles) . The life span of RBC is 120 days . After 120 days , the RBCs are destroyed in the Red Pulp of the Spleen. So the Spleen is known as the Graveyard of RBC

7. FUNCTIONS The spleen serves two main functions : It filters the blood to remove the old/damaged RBCs . ( Red Pulp ) It serves as a secondary lymphoid organ removing infectious agents and using them to activate the lymphocytes . ( White Pulp ) 2. Spleen plays an active role in the production of Ig M antibodies & complements . Has significant role in the functional maturation of antibodies . 3. The spleen is the site of destruction of autoimmune disease states ( Haemolytic anaemia ) . 4. During foetal development spleen helps in production of WBCs & RBCs (Haematopoiesis) .

8. Blood and nerve supply BLOOD SUPPLY : Blood enters the spleen through the splenic artery , moves through the venous sinuses where it is filtered , then leaves through the Splenic vein . NERVE SUPPLY : The spleen is predominantly supplied by the Sympathetic nerves from the Coeliac Plexus . The fibres supply the blood vessels and the smooth muscles of the trabeculae .

9. Clinical importance SPLENOMEGALY : Enlarged spleen due to cancer , especially blood-based leukemia . ASPLENIA : Where the spleen is not present . HYPOSPLENIA : Reduced spleen functions . SPLENECTOMY : A surgical procedure that partially or completely removes the spleen .