Fagosytoosille

Fagosytoosille, often referred to as phagocytosis, is a cellular process whereby a cell engulfs larger particles or cells. This is a form of endocytosis, meaning the cell membrane folds inward to capture the material. The term "phagocytosis" literally translates from Greek as "cell eating." It is a crucial mechanism for many organisms, particularly in the immune system of multicellular animals.

In higher organisms, professional phagocytes such as macrophages, neutrophils, and dendritic cells are responsible for clearing pathogens, dead cells, and debris from tissues. These cells recognize target particles, often opsonized (coated with antibodies or complement proteins), and extend pseudopods, which are arm-like projections of the cell membrane, to surround and engulf the target. The engulfed material is then enclosed within a membrane-bound vesicle called a phagosome.

Once inside the cell, the phagosome fuses with lysosomes, which contain digestive enzymes. This fusion creates a phagolysosome, where the internalized material is broken down and neutralized. The cellular debris or digested contents are then eliminated from the cell, or the cell may absorb useful nutrients. Phagocytosis plays a vital role in innate immunity, tissue homeostasis, and development. It is also employed by single-celled organisms like amoebas to obtain nutrients.