BIOL121 Lecture Notes - Lecture 6: Macrophage, Thymosin, Mediastinum
1 Aug 2018
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Drain excess fluid and proteins from all tissues back to blood circulation. Transport fats and vitamins from the gut to your liver (digestion: immune cells lymphocytes. Identify, attack and develop immunity to a specific pathogen: detect problems, travel into the site of injury or infection, enter and leave the capillaries. Lymphocyte production: lymphoid tissues e. g. tonsils, lymphoid organs e. g. spleen and thymus, red bone marrow. Mature in bone marrow or thymus: lymph. Enemies they seek out and destroy: foreign cells (microbes, foreign proteins, cancer cells. Lymph flows through special tubes from tissues to venous system: lymphatic capillaries. Structure similar to blood capillaries, except: start as pockets rather than continuous tubes, have larger diameters, have thinner walls, flat or irregular outline in sectional view. Structure helps to let fluid in, but not out: overlapping endothelial cells open when tissue fluid pressure is high (one-way valve, allows fluids, solutes and viruses and bacteria to enter, prevents return to intercellular space.
