General Histology Lec 8 Spleen PDF

Lec 8 ‫فردوس حميد عبو‬.‫د‬ ‫مدرس مساعد‬ ‫سنان‬4‫جامعة الحدباء كلية طب ا‬ Spleen: is the largest accumulątion of lymphoid tissue in the body, lies i...

Lec 8 ‫فردوس حميد عبو‬.‫د‬ ‫مدرس مساعد‬ ‫سنان‬4‫جامعة الحدباء كلية طب ا‬ Spleen: is the largest accumulątion of lymphoid tissue in the body, lies in the left hypochondrium beneath the diaphragm extending in the area between 9th & 11th ribs. s Histological structure: The spleen is surrounded by connective capsule containing few smooth muscle fibers from which connective tissue trabeculae extend even to reach the red pulp containing nerves & Vessels The spleen is formed of 2 areas: white pulp & red pulp The white pulp also called splenic pulp or Ma'pighian corpusde is formed of aggregations of lymphocytes which are mainly B-lymphocytes arranged as multiple lymphatic nodules differ from that of the lymph node in that they contain "central artery" surrounded by a sheath of T- lymphocytes) it could be eccentric, sometimes two sections of the central artery is seen in one lymphatic nodule, or may be the nodule shows no central artery. The redpuip formed of two elements: Splenic cords: which are formed of lymphocytes (mainly B- lymphocytes) with all types of blood cells (RBCS, granular leukocytes, platelets, plasma cells & macrophages) arranged in the form of thin cords. Venoussinusoids are irregular dilated blood spaces containing blood lie between the splenic cords, they are lined with cubical epithelium with gaps in between the cells lie on an incomplete basal lamina & they are surrounded by reticular fibers& macrophages. Function of Spleen: formation of lymphocyte immunity for the body development of new RBCs which are stored in the spleen thus its act as a reservon for the it can give the Blood whenever it is needed such as after car accident