When a human cell gets an external stimulus it triggers the production of the specific compound or chemical release which is packed in vesicles from the endoplasmic reticulum and Golgi apparatus to the cell membrane. The cell membrane is the cell organelle that allows or prohibits the entry or exit of any substance.
Chemical release or secretion also depends on the cell membrane and it allows the secretion of chemicals and plays an important role in the secretion of chemical, hormones, or any substance.