Fagocitózisa

Fagocitózisa is a fundamental cellular process by which certain cells engulf and eliminate foreign particles, microorganisms, or cellular debris. This process is primarily carried out by specialized cells known as phagocytes, which include macrophages, neutrophils, and dendritic cells. The term "fagocitózisa" originates from Greek words meaning "to eat" and "cell."

The mechanism of fagocitózisa involves several distinct steps. Initially, the phagocyte recognizes the target particle, often through specific receptors on its surface that bind to molecules present on the particle. Following recognition, the phagocyte extends its cell membrane, forming pseudopods that surround and engulf the particle. This engulfment results in the formation of a membrane-bound vesicle within the phagocyte called a phagosome.

Once the phagosome is formed, it fuses with lysosomes, which are organelles containing potent digestive enzymes and reactive oxygen species. This fusion creates a phagolysosome, where the ingested material is broken down and degraded. The resulting waste products are then expelled from the cell, or in some cases, are utilized by the phagocyte.

Fagocitózisa plays a crucial role in the immune system, serving as a primary defense mechanism against invading pathogens like bacteria and viruses. It is also vital for tissue homeostasis, clearing away dead or damaged cells and preventing the accumulation of cellular waste. Furthermore, phagocytes involved in fagocitózisa can present antigens from the engulfed material to other immune cells, initiating adaptive immune responses.