Lymphatic System PDF

LYMPHATIC SYSTEM DR.ANIL KUMAR MD (ANATOMY) E-mail: [email protected]  LEARNING OBJECTIVES Study the Components and Function of lymphatic system Define lymph and Pathway of its circulation To classify lymphatic organs into primary & secondary Know the microscopic s...

LYMPHATIC SYSTEM DR.ANIL KUMAR MD (ANATOMY) E-mail: [email protected]  LEARNING OBJECTIVES Study the Components and Function of lymphatic system Define lymph and Pathway of its circulation To classify lymphatic organs into primary & secondary Know the microscopic structure and function of the lymphatic organs To understand & describe the microscopic structures of Lymph node, Thymus, Palatine tonsil, Peyer patches of ileum, Appendix, and Spleen Ref.: Junqueira’s Basic Histology Text & Atlas. 13 th Edition; Page- 262-288.  LYMPH Fluid similar to blood plasma Filters out of blood No erythrocytes or platelets vessels Less proteins Lymph capillaries More leukocytes collect interstitial fluid Lymphatic System Components:  Network of lymphatic capillaries,  Lymphatic vessels,  Large lymphatic ducts,  Lymph nodes  Lymphatic organs. Functions  Return tissue fluid to the bloodstream  Transport fats from the digestive tract to the bloodstream  Surveillance & defense This system is concerned with the circulation of the fluid lymph and production of lymphocytes.  RELATIONSHIP OF LYMPHATIC VESSELS AND BLOOD VESSELS Lymph flows only toward the heart follows one way stream  Lymphatic Capillaries  Highly permeable, collect excess tissue fluid,  Widespread in body,  Absent in bone , teeth, CNS  Thin walled and lined with endothelium.  Form plexuses (net work).  Unite to form large lymph vessels.  Lymphatic Capillaries (Lacteals) The small intestine contains special types of lymphatic capillaries called lacteals. Lacteals pick up not only interstitial fluid, but also dietary lipids and lipid-soluble vitamins. The lymph of this area has a milky color due to the lipid and is also called chyle.  Lymphatic vessels  Lymphatic capillaries join to form the lymphatic vessels known as Lymphatics.  Alternate pathway for the return of tissue fluid to the veins.  Wall thinner than the veins of the corresponding caliber.  Lymphatics are transparent and have numerous valves.  Lymphatic vessels  Lymphatics ultimately deliver lymph into 2 main channels Right lymphatic duct  Drains right side of head & neck, right arm, right thorax  Empties into the right subclavian vein Thoracic duct  Drains the rest of the body  Empties into the left subclavian vein Lymphatic vessels are arranged as Drain the superficial tissues and A. superficial vessels accompany the superficial veins B. Deep vessels Drain the deep tissues and accompany the deep blood vessels Lymphatic ducts Lymphatics join to form the larger vessels known as lymphatic trunks The terminal lymphatic ducts are 1. Thoracic duct 2. Right lymphatic duct  Click to edit Master title style  right and left jugular trunks  right and left subclavian trunks  right and left bronchomediastinal trunks  right and left lumbar trunks  intestinal trunk  Lymphatic Cells 24- Also called lymphoid cells. 13 Located in both the lymphatic system and the cardiovascular system. Work together to elicit an immune response. Types of lymphatic cells are: – Macrophages – Epithelial cells – Dendritic cells – Lymphocytes  LYMPHATIC ORGANS Primary organs – Red bone marrow – Thymus gland Secondary organs – Lymph nodes – Lymph nodules – Spleen Lymph Tissue : Three types: Diffuse lymphatic tissue No capsule present Found in connective tissue of almost all organs Lymphatic nodules No capsule present Oval-shaped masses Found singly or in clusters Lymphatic organs Capsule present Lymphatic organs consists of Lymph nodes, spleen, Lymphnode thymus gland Thymus Spleen Tonsils largest