What is the term for the body's process of secreting substances out of the cell?

The body's process of secreting substances out of the cell is known as exocytosis. This process involves the transport of materials contained in vesicles to the cell membrane, where the vesicle membrane fuses with the cell membrane, allowing the contents to be released into the extracellular space. Exocytosis is crucial for various physiological functions, such as the release of hormones, neurotransmitters, and digestive enzymes, and it serves an important role in maintaining the functional integrity of cells.

On the other hand, endocytosis refers to the process by which cells internalize substances by engulfing them, which is essentially the opposite of exocytosis. Transcytosis is a specialized form of endocytosis that involves the transport of substances across a cell, rather than their secretion. Phagocytosis, often referred to as "cell eating," is a specific type of endocytosis that involves the engulfment of large particles or pathogens. Thus, exocytosis stands out as the correct term for the process of secretion from the cell.