Phagocytosis and pinocytosis

In endocytosis, membranes invaginate (like when you put a finger to an inflated balloon) to form a vesicle, leading the way materials within the cell. This process can take several forms, each involving its own specific cellular machinery.

In phagocytosis (cell eating the equivalent), the cell engulfs debris, bacteria, or other large objects. Phagocytosis is carried out in specialized cells called phagocytes, which includes macrophages, neutrophils and other white blood cells. The invagination produces a vesicle called phagosome, which are usually fused with one or more lysosomes containing hydrolytic enzymes. The materials in the phagosome are broken and degraded by these enzymes.

In pinocytosis (the equivalent of eating cell) cell engulfs extracellular fluid, including molecules such as sugar and protein. These materials enter the cell in a vesicle, but not mix with the cytoplasm. The epithelial cells in capillaries, pinocytosis used to make the liquid portion of blood in the capillary surface. The resulting vesicles travel through the hair cells and release their contents into the tissue around it, while blood cells remain in the blood.