Fagocitosis

Phagocytosis is a type of endocytosis, often described as cell eating. It begins when receptors on the cell surface bind to a particle that the cell will engulf.

After the cell recognizes the particle, it extends a projection called a pseudopod.

In mammals, the particle is often an invading microorganism or cellular debris from damaged tissue.

The pseudopod surrounds the particle, and the membranes fuse to form a membrane-bound vesicle called a phagosome. This vesicle contains the engulfed material.

The phagosome then moves through the cytoplasm and fuses with a lysosome. This fusion forms a phagolysosome, where enzymes digest the engulfed material.

In mammals, specialized immune cells such as macrophages, neutrophils, and dendritic cells carry out phagocytosis.