Lymphatic System

Study What is the primary function of the Lymphatic System? The production, maintenance and distribution of blood cells, called lymphocytes What is the secondary function of the Lymphatic System? To maintain the volume balance between the blood and the interstitial fluids. B Lymphocytes (B Cells) are responsible for synthesizing and secreting proteins called antibodies that recognize and attack invading microbes and foreign cells called "Humoral Immunity" T Lymphocytes (T Cells) are cells that recognize and attack microbes and foreign cells by attaching and secreting toxins that kill the invaders. "Cell-Mediated Immunity" - attacking the invader directly. Natural Killer Cells (NK Cells) recognize and kill abnormal cells in the body, such as cancer cells. They work similar to T Cells What are Lymphocytes? A type of white blood cell responsible for mediating the immune response. There are three types. Lymph capillaries differ from blood capillaries in that they have no basement membrane, have large pores in their walls to allow non-selective movement of large molecules, and they dead end into the tissues. The left (thoracic) lymph duct drains into the left subclavian vein from the left side of the body and the right side that is inferior to the diaphragm. The right lymph duct drains into the right subclavian vein from the right side of the body that is superior to the diaphragm. What are the three mechanisms which keep lymph flowing? Smooth muscle layer of lymph trunks and one-way valves, contraction of skeletal muscle, negative pressure in the thoracic cavity created by respiratory pumps. Lymphoid tissues are connective tissues that have accumulations of lymphocytes. MALT stands fo