fixed phagocyte
Học thuậtThân thiện
Definition
Noun: A fixed phagocyte is a type of phagocyte (a cell that engulfs and absorbs bacteria, foreign particles, and dying cells) that is stationary and embedded within specific tissues of the body, rather than circulating freely in the bloodstream.
Usage
This term is used specifically in the fields of biology, immunology, and medicine to describe resident phagocytic cells that are a permanent part of an organ's structure. - Fixed phagocytes in the liver, called Kupffer cells, are crucial for filtering pathogens from the blood. - Unlike macrophages that can migrate, a fixed phagocyte remains in place within tissues like the spleen or bone marrow.
Examples
- The spleen contains numerous that help remove old red blood cells.
- A primary function of in the lymph nodes is to capture and destroy antigens.
Advanced Usage
- Histological Context: When examining tissue samples under a microscope, scientists can identify by their location and characteristic appearance within the stromal (supporting) tissue of organs.
- Contrast with Mobile Phagocytes: The term is often used in contrast to "wandering" or "free" phagocytes, such as monocytes and neutrophils, which travel through the blood and lymphatic systems.
Variants and Related Words
- Phagocyte (n): The general category of cells to which fixed phagocytes belong.
- Macrophage (n): A large phagocytic cell. Some macrophages are fixed (tissue-resident), while others are mobile.
- Kupffer cell (n): A specific type of fixed phagocyte located in the liver.
- Histiocyte (n): A general term for a fixed phagocyte (or macrophage) in connective tissue.
- Reticuloendothelial system (n): An older term for the system of fixed phagocytes and other cells involved in phagocytosis throughout the body.
Synonyms
- Resident phagocyte
- Stationary phagocyte
- Tissue macrophage (in many, but not all, contexts)
Related Phrases
- Fixed tissue macrophage: A more descriptive phrase synonymous with fixed phagocyte.
- Phagocytic cell of the reticuloendothelial system: A formal phrase linking the cell to a broader physiological system.
Noun
- a phagocyte that does not circulate in the blood but is fixed in the liver or spleen or bone marrow etc.