Apocrine Sweat Gland

An apocrine sweat gland (/ˈæpəkrən/, /ˈæpəˌkraɪn/, or /ˈæpəˌkrin/, from Greek apo– "away" and krinein "to separate") is a sweat gland composed of a coiled secretory portion located at the junction of the dermis and subcutaneous fat, from which a straight portion inserts and secretes into the infundibular portion of the hair follicle. In humans, apocrine sweat glands are found only in certain locations of the body: the axillae (armpits), areola and nipples of the breast, ear canal, eyelids, wings of the nostril, perianal region, and some parts of the external genitalia. Modified apocrine glands include the ciliary glands in the eyelids; the ceruminous glands, which produce ear wax; and the mammary glands, which produce milk. The rest of the body is covered by eccrine sweat glands.

Most non-primate mammals, however, have apocrine sweat glands over the greater part of their body. Domestic animals have apocrine glands at each hair follicle but eccrine glands only in foot pads and snout. Their apocrine glands, like those in humans, produce an odorless, oily, opaque secretion that gains its characteristic odor upon bacterial decomposition. Eccrine glands on their paws increase friction and prevent them from slipping when fleeing from danger.