Holocrine refers to the mode of secretion where whole cells are disintegrated and released along with their secretory product. Synonyms for holocrine include exocrine, merocrine, and apocrine. The term exocrine refers to the mode of secretion where the secretory products are released through ducts onto the surface of an organ. Merocrine refers to the mode of secretion where the secretory products are released through exocytosis. On the other hand, apocrine refers to the mode of secretion where the secretory products are released along with a small portion of the apical portion of the secretory cells. These synonyms are often used in studying the different types of glandular cells within the human body.