KINS 1224 Chapter 21 (21.1): Chapter 21
Document Summary
Chapter 21: the lymphatic and immune systems part 1. The lymphatic system: consists of a network of vessels that penetrate nearly every tissue in the body and a collection of tissues and organs that produce immune cells, 3 functions, fluid recovery. Fluid continually filters from capillaries into tissue spaces and is reabsorbed. 15% is not reabsorbed, and the lymphatic system reabsorbs this excess and returns it to the blood. Fluid passes through lymph nodes where immune cells are. Similar to blood plasma but low in protein. Originates in tissue fluid that has been taken up by lymphatic vessels. Lymph leaving lymph nodes contain a lot of lymphocytes (main supply) May also contain macrophages, hormones, bacteria, viruses, debris, and cancer cells. Bud from veins in the embryo tunica interna with an endothelium and valves, a tunica media with elastic tissue and smooth muscle, and a thin outer tunica externa. Lymphatic cells: natural killer (nk) cells.
