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Sweat glands, also known as sudoriferous or sudoriparous glands, ,〔 are small tubular structures of the skin that produce sweat. Sweat glands are a type of exocrine gland, which are glands that produce and secrete substances onto an epithelial surface by way of a duct. There are two main types of sweat glands that differ in their structure, function, secretory product, mechanism of excretion, anatomic distribution, and distribution across species: * Eccrine sweat glands are distributed almost all over the human body, in varying densities. Its water-based secretion represents a primary form of cooling in humans. * Apocrine sweat glands are mostly limited to the axilla (armpits) and perianal areas in humans. They are not significant for cooling in humans, but are the sole effective sweat glands in hoofed animals, such as the camels, donkeys, horses, and cattle.〔 Ceruminous glands (which produce ear wax), mammary glands (which produce milk), and ciliary glands in the eyelids are modified apocrine sweat glands.〔〔 ==Structure== Generally, sweat glands consist of a ''secretory unit'' consisting of a base rolled into a glomerulum, and a ''duct ''that carries the sweat away.〔 The ''secretory coil ''or base, is set deep in the lower dermis and hypodermis, and the entire gland is surrounded by adipose tissue.〔〔 In both sweat gland types, the secretory coils are surrounded by contractile myoepithelial cells that function to facilitate excretion of secretory product. The secretory activities of the gland cells and the contractions of myoepithelial cells are controlled by both the autonomic nervous system and by the circulating hormones. The distal or apical part of the duct that opens to the skin's surface is known as the ''acrosyringium''. Each sweat gland receives several nerve fibers that branch out into bands of one or more axons and encircle the individual tubules of the secretory coil. Capillaries are also interwoven among sweat tubules.〔 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Sweat gland」の詳細全文を読む スポンサード リンク
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