Definition
noun, plural: macrophages
A leukocyte whose main function is to eliminate cellular debris and foreign particles through phagocytosis
Supplement
White blood cells (also called leukocytes) are cells of the immune system. They are called white due to the lack of the hemoglobin pigment, which is present in red blood cells. Similar to red blood cells though, the white blood cells also came from a hematopoietic stem cell (hemocytoblast). The hemocytoblast gives rise to progenitor cells for both the myeloid series and the lymphoid series. The macrophage is a white blood cell derived from the common myeloid progenitor cell. In the monocyte-macrophage series, the developmental stages are as follows: hemocytoblast –> common myeloid progenitor (also called CFU-GEMM) –> CFU-GM –> CFU-M –> monoblast –> promonocyte –> monocyte –> macrophage.
The monocyte is a white blood cell in the bloodstream that is capable of immune function, such as phagocytosis, cell signaling, and antigen presentation. When monocyte migrates into the tissue spaces, it divides/differentiate into a macrophage, which is also capable of similar immune functions.
Macrophages are found throughout the body and some of them take on various forms (and names):
- macrophages in adipose tissue: adipose tissue macrophages (ATMs)
- macrophages in bone: osteoclasts
- macrophages in central nervous system: microglia
- macrophages in connective tissues: histiocytes leading to giant cells
- macrophages in granulomas: epithelioid cells
- macrophages in kidney: intraglomerular mesangial cells
- macrophages in liver: Kupffer cells
- macrophages in lungs: alveolar macrophages (or dust cells)
- macrophages in lymph nodes: sinus histiocytes
- macrophages in peritoneal cavity: peritoneal macrophages
- macrophages in Peyer’s patch: LysoMac
- macrophages in placenta: Hofbauer cell
- macrophages in spleen (red pulp): red pulp macrophages
Word origin: Greek makrós (“large”) + phageín (“to eat”)
See also:
Related term(s):
Related form(s):
- macrophagocytic (adjective)
