Apocrine sweat glands
Apocrine sweat glands are sweat glands composed of a coiled secretory portion located at the junction of the dermis
The dermis is a layer of skin between the epidermis and subcutaneous tissues, and is composed of two layers, the papillary and reticular dermis...

 and subcutaneous fat, from which a straight portion inserts and secretes into the infundibular portion of the hair follicle
Hair follicle
A hair follicle is a skin organ that produces hair. Hair production occurs in phases, including a growth phase , and cessation phase , and a rest phase . Stem cells are principally responsible for the production of hair....

. In humans, apocrine sweat glands are found only in certain locations of the body: the axillae (armpits), the areola
This article is about the breast tissue. For the entomology term, see the glossary of Lepidopteran terms. For an artistic cloud motif, see aureola. For the cactus feature, see Areole....

 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
A misnomer is a term which suggests an interpretation that is known to be untrue. Such incorrect terms sometimes derive their names because of the form, action, or origin of the subject becoming named popularly or widely referenced—long before their true natures were known.- Sources of misnomers...

. While it was once thought that apocrine sweat glands were true apocrine
Apocrine is a term used to classify exocrine glands in the study of histology. Cells which are classified as apocrine bud their secretions off through the plasma membrane producing membrane-bound vesicles in the lumen. This method is also called decapitation secretion...

 glands, it is now known that they use merocrine
Merocrine is a term used to classify exocrine glands and their secretions in the study of histology. A cell is classified as merocrine if the secretions of that cell are excreted via exocytosis from secretory cells into an epithelial-walled duct or ducts and thence onto a bodily surface or into the...

 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
A hormone is a chemical released by a cell or a gland in one part of the body that sends out messages that affect cells in other parts of the organism. Only a small amount of hormone is required to alter cell metabolism. In essence, it is a chemical messenger that transports a signal from one...

 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
Body odor
Body odor or body odour, sometimes colloquially abbreviated as B.O., is the smell of bacteria growing on the body. The bacteria multiply rapidly in the presence of sweat, but sweat itself is almost completely odorless to humans....

. 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
Lumen (anatomy)
A lumen in biology is the inside space of a tubular structure, such as an artery or intestine...

Another distinction is that apocrine sweat glands secrete a more viscous fluid.

External links

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