Apocrine sweat glands

Apocrine sweat glands are sweat glands 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), the areola of the nipples, and the genitoanal region. Specialized types of apocrine sweat glands present on the eyelids are called Moll's glands. Most of the human body contains eccrine sweat glands.

The term apocrine sweat gland is a misnomer. While it was once thought that apocrine sweat glands were true apocrine glands, it is now known that they use merocrine excretion. However, they have retained the original name.

Apocrine sweat glands are inactive until they are stimulated by hormonal changes in puberty. Apocrine sweat glands are mainly thought to function as olfactory pheromones, chemicals important in attracting a potential mate. The stimulus for the secretion of apocrine sweat glands is adrenaline, which is a hormone carried in the blood.

Apocrine sweat glands secrete a milky, viscous, odourless fluid which only develops a strong odour when it comes into contact with bacteria on the skin surface.

East Asians have fewer apocrine sweat glands compared to people of European or African descent, and it may be for this reason that they are less prone to body odor. Studies have also shown that African Americans have larger and more numerous apocrine sweat glands than other Americans.

An important distinction between an eccrine sweat gland and an apocrine sweat gland structure is that an apocrine sweat gland has a larger lumen. Another distinction is that apocrine sweat glands secrete a more viscous fluid.