Final answer:
Exocrine glands can be classified functionally into merocrine, holocrine, and apocrine divisions.
Step-by-step explanation:
Exocrine glands can be classified functionally into merocrine, holocrine, and apocrine divisions. Merocrine secretion is the most common type of exocrine secretion where the secretions are enclosed in vesicles that move to the apical surface of the cell and are released by exocytosis. Holocrine secretion involves the rupture of gland cells to release their secretions, and apocrine secretion involves the pinching off of the apical portion of the cell to release secretions.