PNB 2265 Lecture Notes - Lecture 13: Mucosa-Associated Lymphoid Tissue, Motility, Natural Killer Cell
15 Feb 2017
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Document Summary
Defense mechanisms of the body i: non-specific (innate immune defenses) Non-specific (innate immune) v. specific (adaptive immune) defense mechanisms. Analogy (courtesy of dr. moiseff): bank walls (keep robbers out) vs. surveillance camera (to identify specific bank robber) Defend/protect against infection by microbes: viruses, bacteria, fungi, other parasites. negative aspect: allergies/hypersensitivity, autoimmune diseases, organ transplant reactions. Capillaries are blind-ended, located at vascular capillary beds c) lymphoid tissues / lymphoid organs. Secondary: lymph nodes, spleen, peyer"s patches, tonsils. Filters out more fluid than you reabsorb in your capillary bed and the lymphatic system picks it up (lymph) Lymphoid organs (all have a fibrous connective tissue capsule) Primary lymphoid organs = bone marrow and thymus ( lymphoid tissue ) Site of maturation for b lymphocytes; production of all leukocytes. Capsule of fibrous tissue; partitions (differentiated from nodules) Lymph nodes have this capsule, so they are organs. Found in certain tissues; if activated migrate to lymph nodes to present antigen.
