Caption: Tissue macrophages, monocyte and human red blood cell from a leg wound. * Note in this image two monocytes (that have migrated into the wound area) are still developing into tissue macrophages (cells on left edge of image). A tissue macrophage is a large, mature phagocyte that can ingest and destroy invading microbes, foreign particles, cancerous or diseased cells and cellular debris. A monocyte is a circulating phagocyte that ingests microbes, invading particles, and cellular debris. Monocytes leave the blood stream and usually mature into tissue macrophages. Monocytes and macrophages are both part of the reticuloendothelial system. Lymphocytes are involved in the specific immune response and are composed mainly of precursor T cells and B cells (pre-T cells and B cells). Pre-T cells and B cells are subsets of lymphocytes that originate in the red bone marrow from hematopoietic stem cells. Pre-T cells (also known as T lymphocytes) circulate in the blood before migrating to the thymus where they develop into specialized cells (helper T cells and killer T cells) that are able to identify antigens and infected tissue cells.
Magnification*: x1,000
Type: SEM
Copyright 2004 Dennis Kunkel Microscopy, Inc.
Keywords: 01.01.04,21362bw,b/w,blood,helper T cell,hematopoietic,histiocyte,immune response,killer T cell,leukocyte,macrophage,medical,monocyte,monohistocytic series,phagocyte,phagocytic,phagocytosis,pre T cell,red blood cell,red blood cells,reticuloendothelial system,tissue macrophage,white blood cell,white blood cells,wound,SEM