Fagocitóze

Fagocitóze is a cellular process by which certain cells, known as phagocytes, engulf and internalize large particles. This process is a form of endocytosis, where the cell membrane surrounds the particle and pinches off to form a vesicle inside the cell. Fagocitóze plays a crucial role in the immune system, where phagocytes like macrophages and neutrophils engulf pathogens such as bacteria, viruses, and fungi, as well as cellular debris. This elimination of foreign invaders and waste products is essential for maintaining tissue health and preventing disease.

The process typically begins with the recognition of the particle by receptors on the phagocyte's surface. This recognition can be direct, where the phagocyte recognizes specific molecular patterns on the particle, or indirect, where the particle is coated with opsonins, molecules that enhance phagocytosis. Once the particle is bound, the phagocyte extends its pseudopods, which are arm-like projections of the cell membrane, to surround and engulf the particle. This creates a membrane-bound sac called a phagosome, which then fuses with lysosomes, organelles containing digestive enzymes. The contents of the phagosome are broken down by these enzymes, effectively destroying the engulfed material. Fagocitóze is not limited to immune cells; it is also involved in developmental processes, tissue remodeling, and nutrient acquisition in some organisms.