Fagócitos

Fagócitos are specialized cells in the immune system responsible for engulfing and eliminating foreign particles, pathogens, and cellular debris. The term "fagócito" originates from the Greek words "phagein" (to eat) and "kytos" (cell), accurately describing their phagocytic function.

These cells are a crucial component of the innate immune response, providing a first line of defense against invaders. They circulate in the bloodstream and tissues, constantly patrolling for threats. When a fagócito encounters a foreign substance, it extends its cell membrane to surround and internalize the particle into a vesicle called a phagosome.

Once inside the fagócito, the phagosome fuses with lysosomes, which contain powerful digestive enzymes and toxic substances. These enzymes break down the engulfed material, neutralizing pathogens and digesting cellular debris. This process is vital for clearing infections and maintaining tissue homeostasis.

Key types of fagócitos include macrophages and neutrophils. Macrophages are larger and longer-lived, found in tissues throughout the body, where they play roles in both innate and adaptive immunity. Neutrophils are abundant in the blood and are among the first responders to sites of infection or inflammation, rapidly engulfing and destroying bacteria.

Fagócitos also play a role in initiating adaptive immune responses by presenting fragments of engulfed pathogens to lymphocytes, thereby activating a more specific and targeted immune attack. Their ability to eliminate harmful substances and dead cells makes them indispensable for maintaining health and preventing disease.