Phagocytosis

Phagocytosis is a special form of endocytosis in which large particles, such as microorganisms or dead cells, are taken up into large endocytosis vesicles, the phagosomes. Phagocytosis and macropinocytosis are two processes that differ little morphologically. In both cases, protrusions called pseudopodia are first formed from the cell membrane, enclosing the object to be endocytosed, enclosing it in a vesicle, and then transferring it to the interior of the cell. Actin filaments are involved in the formation of the protrusions, making the inhibitor cytochalasin D particularly useful for blocking these uptake pathways.

After strangulation of the vesicles, the phagosomes or macropinosomes (macropinocytosis), are biochemically modified in several steps and finally transported to lysosomes. Here, degrading enzymes are located, which digest and degrade the ingested material as much as possible.

The most important examples of phagocytic cells are leukocytes and macrophages, which use this pathway to destroy pathogens or recycle the body's own material.

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