What process involves the release of substances from a cell via vesicles?

The process that involves the release of substances from a cell via vesicles is exocytosis. This mechanism is crucial for various cellular functions, such as the secretion of hormones, neurotransmitters, and other important biomolecules. In exocytosis, intracellular vesicles containing these substances move to the cell membrane, fuse with it, and release their contents into the extracellular space. This process is vital for maintaining communication between cells and for the overall functioning of tissues and organs.

Endocytosis, as a contrast, refers to the process of bringing substances into the cell rather than releasing them. Phagocytosis and pinocytosis are specialized forms of endocytosis; phagocytosis involves the uptake of large particles, while pinocytosis involves the uptake of liquids. These processes focus on the absorption of materials rather than their secretion.