Article: Sweating

For the plumbing term, see: soldering

Sweating (also called perspiration or sometimes transpiration) is the loss of a watery fluid, consisting mainly of sodium chloride (commonly known as salt) and urea in solution, that is secreted by the sweat glands in the skin of mammals. Sweat also consist of the chemicals or odorants 2-methylphenol and 4-methylphenol.

In humans, sweating is primarily a means of temperature regulation. Evaporation of sweat from the skin surface has a cooling effect due to the latent heat of evaporation of water. Hence, in hot weather, or when the individual's muscles heat up due to exertion, more sweat is produced. Sweating is increased by nervousness and nausea and decreased by cold. Animals with few sweat glands, such as dogs, accomplish similar temperature regulation results by panting, which evaporates water from the moist lining of the oral cavity and pharynx. Primates and horses have sweat glands in their skin, similar to humans.

Sweat glands

In humans, there are two kinds of sweat glands which differ greatly in both the composition of the sweat and its purpose:

• Eccrine sweat glands are distributed over the entire body surface but are particularly abundant on the palms of hands, soles of feet, and on the forehead. These produce sweat that is composed chiefly of water with various salts. These glands are used for body temperature regulation.
• Apocrine sweat glands produce sweat that contains fatty materials. These glands are mainly present in the armpits and around the genital area and their activity is the main cause of sweat odour, due to the bacteria that break down the organic compounds in the sweat from these glands.

See also

• Diaphoresis
• Hyperhidrosis
• Anhidrosis
• Hyponatremia
• Hyperthermia
• Body odor
• Hidradenitis suppurativa
• Sweat drop