Anatomy of spleen

anatomy of spleen

1. Dr . BISHRITA SWAIN, (MS,AYU .) SPLEEN

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3. INTRODUCTION:- Spleen(Greek splen and Latin lien ) is a lymphatic organ connected to the blood vascular system. It acts as a filter for blood and plays an important role in the immune response of the body. The Spleen is a wedge-shaped organ lying mainly in the left hypochondrium , and partly in the epigastrium The spleen lies against the diaphragm, in the area of rib 9 th to 10 th .

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5. DIMENSIONS:- The spleen is soft, highly vascular and dark purple in colour . The size and weight of spleen are markedly variable . On an average the spleen in 1 inch thick, 3 inch broad, 5 inch long, 7 ounces in weight, and is related to 9th to 11th ribs . 1,3,5,7,9,11 Harris D ictor phenomemenon

6. POSITION:- The spleen lies obliquely along the long axis of 10 th rib. Thus it is directed downwards, forward and laterally, making an angel of about 45 degree with the horizontal plane .

7. EXETERNAL FEATURES :- The spleen has 2 ends, 3 boarders 2 surfaces 2 angles Hilum . TWO ENDS :- The ANTERIOR END is expanded and is more like a border. It is directed downward and forwards, and reaches the midaxillary line . POSTERIOR END is rounded . It is directed upwards, backwards and medially , and rests on the upper pole of the left kidney.

8. Three borders :- The superior border is characteristically notched near the anterior end . The inferior border is rounded . The intermediate border is also rounded and is directed towards right . Two surfaces :- The diaphragmatic surface is convex and smooth . The visceral surface is concave and irregular .

9. a Two angles:- Anterobasal angle – It is the junction of superior border with lateral and anterior end of spleen . When spleen is enlarged this part felt first, so this is called ‘ clinical angle of spleen’ Posterobasal angle – Junction of inferior border with lateral or anterior end of spleen . Hilum :- Hilum lies between the superior and intermediate border , pierce by branches and tributaries of splenic vessels

10. *RELATIONS* Peritoneal relations Visceral reations Peritoneal relations The spleen surrounded by peritoneum and suspended by following ligaments . ( a) Gastrosplenic ligament expands from the hilum of the spleen to the greater curvature of stomach . It. Obtains the short gastric vessel and associated lymphatic and sympathetic nerves. (b) Lienorenal ligament expands from the hilum of the spleen to the anterior surface of left kidney . It contain the tail of pancreas, the splenic vessels and associated pancreaticosplenic lymph nodes, lymphatic sand sympathetic nerves (c) Phrenicoclic ligaments is not attached to the spleen , but supports its anterior end . It is the horizontal fold of peritoneum extending from the splenic flexure of colon to the diaphragm . Also called sustentaculum lienis .

11. RELATIONS Visceral surface

12. 4 impression present are visceral surface of spleen for abdominal organ and other structures- Gastric impression Renal impression pancreatic impression Hilum lies on the inferomedial part of the gastric impression along the long axis of the spleen . Diaphragmatic surface- The surface separates the spleen from the costodiaphragmatic recess of pleura, lung and 9 th ,10 th , 11 th ribs of the left side.

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14. Arterial supply- SPLENIC ARTERY OR LIENAL ARTERY {the largest branch of coeliac trunk } superior border of the pancreas . splenorenal ligament divides into numerous branches enters the hilum of the spleen . Approaching the spleen the splenic artery gives off short gastric arteries, gastrosplenic ligament to supply the fundus of the stomach . *** gastro- omental artery , (which runs along the grater cuvature of stomach) & anstomoses with the **** right gastro- omental artery .

15. SPLENIC ARTERY

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17. VENOUS SUPPLY:- The splenic vein is formed at the hilum of the spleen . It runs a straight course behind the pancreas . It joins the superior mesenteric vein behind the neck of pancreas to form the portal vein. Its tributaries are the short gastric, left gastroepiploic , pancreatic and inferior mesentric veins.

18. HISTOLOGY OF SPLEEN:- There are two types of tissues in spleen ( specialised for its main function  White pulp contains lymphoid aggregations , mostly lymphocytes and macrophages which are arranged around the arteries . The lymphocytes are both T( mainly T-helper) and B-cells . Red pulp is vascular, and has parencyhma and lots of vascular sinus . These are sinuosoids – a specialised type of capillary, which is very leaky . these cell population includes: a. All types of lymphocytes (small, medium and large) b. All types of blood cells (RBC, WBC and Platelets) and c. The fixed and free macrophages . Lymphocytes are freely transformed into plasma cells which can produce large amount of antibodies the immunoglobins .

19. LYMPHATIC DRAINAGE :- Splenic tissue proper has no lymphatics . A few lymphatics arise from the connective tissue of the capsule and trabeculae . Drain into the pancreato splenic lymph nodes situated along the splenic artery . NERVE SUPPLY:- Sympathetic fibres are derived from the coeliac plexus. They are vasomotor in nature . They also supply some smooth muscle present in the capsule .

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21. a FUNCTION OF SPLEEN:- Haemopoiesis – The spleen is an important haemopoitic organ during life. Lymphopoiesis continues through life . In adult spleen haemopoiesis can restart in certain disease like chronic myeloid leukemia and myesclerosis . Phagocytosis – The spleen is an important component of reticuloendothelial system . Immuneresponses – Under antigenic stimulation, there occurs increased lymphopoiesis for cellular responses and increased formations of plasma cells to the humoral responses . Storage of RBC:- RBC can be stored in the spleen and released in to the circulation when needed .

22. CLINICAL ANATOMY

23. Palpation of spleen :- A normal spleen is not palpable , but a enlarged spleen can be felt under the left costal margin . Splenomegaly :- Enlargement of spleen is called splenomegaly. Sometimes the spleen becomes very large ,it then projected towards the right iliac fossa in the direction of the axis of the 10 th rib .

24. a SPLENECTOMY:- Surgical removal of spleen. During this operation of damage to tail of the pancreas to be avoided. Partial splenectomy :- Since there are segmental branches of splenic artery, only one segment can be removed according to the state of spleen . Splenic puncture:- Sp leen can be punctured at the 9 th or 10 th intercostal surface in the mid axillary line using a lumbar punctured needle.

25. a SPLENECTOMY SPLENIC PUNCTURE

26. Multiple choice questions 1. Spleen position to the which region of abdomen (I) epigastric (ii) left hypochondric (iii) umbilical (iv) both i & ii 2. Spleen lies making how much angle with horizontal plane (i) 30 (ii) 45 (iii) 60 (iv) 120 3. Shape of visceral surface (i) concave (ii) convex (iii) irregular (iv) both i & iii 4. Clinical angle of spleen felt in which part of spleen (i) posterobasal angle (ii) diaphragmatic surface (iii) visceral surface (iv) anterobasal angle

27. 5. From hilum of spleen to the greater curvature of spleen, which ligaments extends, (i) lienoenal ligament. (ii) gastrosplenic ligament (iii) phrenicolic ligament. (iv) none of these 6. Visceral surface related to (i) fundas of stomach (ii) anterior surface of left kidney (iii) splenic flexor of the colon (iv) all of these 7. According to open circulation theory, the capillaries end open into (i) red pulp (iii) green pulp (ii) white pulp (iv) all of these 8. How does spleen helps in immune response (i) by releasing stored WBC (ii) increased lymphopoiesis (iii) increased formation of plasma cell (iv) both ii & iii 9. Splenic puncture occurs in which intercostal space (i) 9 th & 10 th (iii) 10 th & 11 th (iii) 7 th & 8 th (iv) 6 th & 7 th 10. Splenomegaly shows which condition of spleen (i) shrunken spleen (ii) Enlarged spleen (iii) surgical removal of spleen (iv) none of these

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