Spleen Anatomy PDF

SPLEEN  Spleen Consists of a large encapsulated mass of vascular and lymphoid tissue situated in the upper left quadrant of the abdominal cavity between the fundus of the stomach and the diaphragm Situated in left, upper, posterior region of left hypocondrium Its long axis l...

SPLEEN  Spleen Consists of a large encapsulated mass of vascular and lymphoid tissue situated in the upper left quadrant of the abdominal cavity between the fundus of the stomach and the diaphragm Situated in left, upper, posterior region of left hypocondrium Its long axis lies approximately in the plane of the tenth rib Its posterior border is approximately 4 cm from the mid-dorsal line at the level of the tenth thoracic vertebral spine In the living Soft Friable Dark purple (depending amount of blood)  Spleen The size and weight of the spleen vary with age and sex It can also vary slightly in the same individual under different conditions Usually 12 cm long, 7 cm broad, and 3–4 cm wide Average adult weight 150 g (80 - 300 g) Has to be at least three times its normal size before it can be palpated Normal spleen is not palpable Functions: Removal of aging erythrocyte from circulation Provision of lymphocytes & antibodies Not essential to survival  Covered by peritoneum (adheres firmly to its capsule) Recesses of greater sac seperate it from stomach and left kidney Connected to o posterior abdominal wall via; Lienorenal lig Phrenicocolic lig Phrenicosplenic lig o stomach via; Gastrosplenic lig  Lienorenal (splenorenal) lig; ▪ Splenic vessels ▪ Tail of pancreas Gastrosplenic lig; ▪ Short gastric a. (splenic artery) ▪ Left gastroepiploic artery (splenic artery)  Diaphragmatic surface Superolateral Convex and smooth Visceral surface Inferomedial Irregular Marked by gastric, renal, pancreatic and colic impressions Superior border Inferior border Ant extremity Posterior extremity Hilum  Visceral Surface Faces abdominal cavity Gastric impression Renal impression Pancreatic impression (tail of pancreas, lies in lienorenal lig) Colic impression (left colic flexure, phrenicocolic lig) Near inf limit; hilum  Covered externally by series of connective tissue bars (trabeculae) Trabeculae ramify to create a fibrous skeleton Trabeculae support lymphoid tissue (white pulp) and blood-filled tissue (red pulp) Variations of spleen Accessory spleens; especially within gastrosplenic lig and greater omentum Small encapsulated nodules of splenic tissue Isolated or connected to spleen by thin bands May retain its fetal lobulated form May show deep notches on diaphragmatic surface and inf border  Aa. of spleen Splenic a. Segmental branches supply splenic segments  Vv. of spleen Minor vv. pass from red pulp into trabeculae Thence into segmental vv. Segmental vv. drain into splenic v. (lienorenal lig) Splenic v. + sup mesenteric v. → Portal v. Lymph vessels of spleen Leave lymph nodes in hilum Pancreaticosplenic lymph nodes Coeliac lymph nodes  Nn. of spleen Celiac plexus Distributed along branches of splenic a. Vasomotor in function Concerned with regulation of blood flow Parasymph: Vagus n. Symph: Greater splanchnic nn. Splenic trauma The spleen is particularly prone Minor capsular tears may be to rotational injury during rapid treated by conservative deceleration or compression management if from blunt Because it has relatively mobile trauma or by application of peritoneal connections, tearing various haemostatic substances injuries to the splenic vessels at to the exposed pulp the hilum or burst injuries of the Direct sutured repair of more splenic pulp may occur extensive tears of the spleen is rarely successful because the splenic pulp is fragile Extensive burst injuries or major injuries to the hilar vessels usually require splenectomy