Microbiology and Immunology 3300B Lecture : Immunology Notes
20 Feb 2012
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Document Summary
Most immune cells are in the circulation (found in the blood). Lymphocytes and myeloid cells are a subclass of immune cells (white blood cells). In adults, immune cells are formed in the bone marrow. Immune cells are found in: blood, lymph, central lymphoid organs (thymus, bone marrow), peripheral lymphoid organs (spleen, lymph nodes), and most tissues. Bone marrow: spongy material found in long bones (arm and legs). Contains developing immune cells and erythrocytes, connective tissue and fat. Central (primary) lymphoid tissues: sites where lymphoid immune cells undergo the final stages of development. T-cells develop in the thymus and b-cells develop in the bone marrow. Peripheral (secondary) lymphoid tissues: sites where mature lymphoid cells scan for cognate antigens. These include the adenoid, tonsil, lymphatic vesicles, lymph nodes, spleen, and peyer s patch (small intestine). Blood/lymph system: capillaries allow small amounts of fluid to leak into tissues. This fluid accumulates antigens present within tissues and the fluid drains into lymphatic vessels.
