How do we classify exocrine glands according to the mode of secretion?

Merocrine : most common, cells produce and eject secretions by exocytosis cell integrity is respected (parotids) Apocrine: Secretory products are gradually accumelated at the apical pole detaching a small part of the cell in the form of a large vacuole ,released respecting integrity of cell membrane (mammary glands) Holocrine: secretory product completely fills cell cyroplasm for the cell undergoes degenration which then ruptures and releases its accumelated secretory substances (sebacceous glands)