BIOL-242 Lecture Notes - Lecture 8: White Blood Cell, Granulocyte, Leukocyte Extravasation
28 Apr 2020
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Document Summary
Makes up <1% of total blood volume. Can leave capillaries via diapedesis ( leaping across ) Move through tissue spaces by ameboid motion and positive chemotaxis. Cytoplasmic granules stain specifically with wright"s stain. Granules stain lilac; contain hydrolytic enzymes or defensins. 3-6 lobes in nucleus; twice size of rbcs. Large, dark purple, circular nuclei with thin rim of blue cytoplasm. Mostly in lymphoid tissue (e. g. lymph nodes, spleen)l few circulate in blood. T lymphocytes (t cells) act against virus-infected cells and tumor cells. B lymphocytes (b cells) give rise to plasma cells, which produce antibodies (attack cells that don"t belong to their body) Leave circulation, enter tissues, and differentiate into macrophages. Actively phagocytic cells; crucial against viruses, intracellular bacterial parasites, and chronic infections. Activate lymphocytes to mount an immune response. Stimulated by 2 types of chemical messengers from red bone marrow and mature wbcs. 3 times more wbcs produced than rbcs. Lymphocytes - live few hours to decades.
