fagocitálás

Fagocitálás is a cellular process by which certain types of cells, known as phagocytes, engulf and ingest larger particles. This process is a fundamental mechanism of the innate immune system, playing a crucial role in defense against pathogens and in the removal of cellular debris. The term originates from Greek words: "phagein" meaning "to eat" and "kytos" meaning "cell".

The process of fagocitálás begins with the recognition of the target particle by the phagocyte. This recognition can occur through various mechanisms, including the binding of receptors on the phagocyte's surface to molecules on the particle. Once recognition is established, the phagocyte extends its cell membrane, forming pseudopods that surround and enclose the particle. This engulfment results in the formation of a membrane-bound vesicle within the phagocyte called a phagosome.

Following engulfment, the phagosome fuses with lysosomes, which are organelles containing digestive enzymes and toxic substances. This fusion creates a phagolysosome, where the ingested particle is broken down and neutralized. The breakdown products are then either absorbed by the cell or expelled from it. Key phagocytic cells in the body include macrophages, neutrophils, and dendritic cells. These cells are essential for clearing infections, initiating adaptive immune responses, and maintaining tissue homeostasis by removing dead or damaged cells.