Dictionary > Monocyte


noun, plural: monocytes
A type of white blood cell capable of immune functions such as phagocytosis, and can further differentiate into a macrophage or a myeloid dendritic cell
Hematopoiesis is the process of forming new blood cellular elements in vertebrates. It begins with a multipotent stem cell, a hemocytoblast, which gives rise to a common myeloid progenitor cell (CMP). The CMP, in turn, gives rise to granulocyte-monocyte colony forming units (CFU-GM), also called granulocyte-macrophage progenitor. The CFU-GM may partially differentiate into CFU-G (precursor in myelocyte-granulocyte series) or CFU-M (precursor in monocyte-macrophage series). The CFU-GM serves as the precursor for monoblasts and myeloblasts.
In the monocytic series, the monoblast is a precursor cell for promonocyte. The promonocyte matures into a monocyte. The monocyte migrates from the bone marrow to the peripheral blood through diapedesis. In humans, it constitutes the 2% to 10% of the white blood cells in the body. A monocyte is capable of immune functions, such as phagocytosis, antigen presentation, and cytokine production. It may leave the bloodstream and enters the connective tissue spaces. When it does, the monocyte divides and/or differentiates into a macrophage. Monocytes may also differentiate into a myeloid dendritic cell. In humans, some of the monocytes are stored in the spleen.
A monocyte is the largest type of white blood cell. Its size may range from 13 to 25 μm in diameter. It may be amoeboid in appearance. Its nucleus is unilobulated. The chromatin has a lacy pattern. When stained with conventional dyes, the cytoplasm appears blue-gray in color with fine, red-blue azurophil granules. Vacuoles are usually present.
As a type of white blood cell (leukocyte), the monocyte belongs to the mononuclear leukocytes as opposed to other white blood cells that are polymorphonuclear.
See also:

Related form(s):

  • monocytic (adjective, of, pertaining to, or relating to a monocyte)

    You will also like...

    New Zealand - Biodiversity fauna
    New Zealand’s Biodiversity

    Find out more about New Zealand's unique biodiversity by exploring a range of different ecosystems and the key role of s..

    Structural depiction of catalase, an enzyme
    Protein Activity and Cellular Metabolism

    Proteins have a crucial role in various biological activities. Get to know how proteins are able to perform as enzymes, ..

    Still Water Community Plants
    Still Water Community Plants

    This tutorial looks at the adaptations of freshwater plants for them to thrive in still water habitats. Familiarize your..

    Cell Respiration
    Cell Respiration

    Cell respiration is the process of creating ATP. It is "respiration" because it utilizes oxygen. Know the different stag..

    Biological Viruses
    Biological Viruses

    Viruses possess both living and non-living characteristics. This unique feature distinguishes them from other organisms...

    Fossil trilobite imprint in the sediment

    There are more species of insects than any other species combined. This surely illustrates that insects have the selecti..