Sweating (also called perspiration or sometimes transpiration) is the loss of a watery fluid, consisting mainly of sodium chloride 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-methyphenol. Transpiration is a continuous process caused by the evaporation of water from leaves of plants and its corresponding uptake from roots in the soil. ... Water (from the Old English word wæter; c. ... Sodium chloride, also known as common salt, table salt, or halite, is a chemical compound with the formula NaCl. ... Urea is an organic compound of carbon, nitrogen, oxygen and hydrogen, with the formula CON2H4 or (NH2)2CO and the structure shown right: Urea is also known as carbamide, especially in the recommended International Non-proprietary Names (rINN) in use in Europe. ... A gland is an organ in an animals body that synthesizes a substance for release such as hormones, often into the bloodstream (endocrine gland) or into cavities inside the body or its outer surface (exocrine gland). ... Model of the layers of human skin In zootomy and dermatology, skin is an organ of the integumentary system; which is composed of a layer of tissues that protect underlying muscles and organs. ... Orders Subclass Monotremata Monotremata Subclass Marsupialia Didelphimorphia Paucituberculata Microbiotheria Dasyuromorphia Peramelemorphia Notoryctemorphia Diprotodontia Subclass Placentalia Xenarthra Dermoptera Desmostylia Scandentia Primates Rodentia Lagomorpha Insectivora Chiroptera Pholidota Carnivora Perissodactyla Artiodactyla Cetacea Afrosoricida Macroscelidea Tubulidentata Hyracoidea Proboscidea Sirenia The mammals are the class of vertebrate animals characterized by the presence of mammary glands...

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. Binomial name Homo sapiens Linnaeus, 1758 Subspecies Homo sapiens idaltu (extinct) Homo sapiens sapiens Human beings define themselves in biological, social, and spiritual terms. ... Temperature is the physical property of a system which underlies the common notions of hot and cold; the material with the higher temperature is said to be hotter. ... Evaporation is the process whereby atoms or molecules in a liquid state (or solid state if the substance sublimes) gain sufficient energy to enter the gaseous state. ... Nausea (Greek Ναυτεία) is the sensation of unease and discomfort in the stomach with an urge to vomit. ... Trinomial name Canis lupus familiaris (Linnaeus, 1758) The Dog is a canine carnivorous mammal that has been domesticated for at least 14,000 years and perhaps for as long as 150,000 years based on recent evidence. ... The pharynx is the part of the digestive system of many animals immediately behind the mouth and in front of the esophagus. ...

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, which are distributed over the entire body surface. These produce sweat that is composed chiefly of water with various salts. These glands are used for body temperature regulation.

Eccrine sweat glands are coiled tubular glands derived from the outer layer of skin but extending into the inner layer. They are distributed over almost the entire surface of the body in humans and many other species, but are lacking in some marine and fur-bearing species. The sweat glands are controlled by sympathetic cholinergic nerves which are controlled by a centre in the hypothalamus. The hypothalamus senses core temperature directly, and also has input from temperature receptors in the skin and modifies the sweat output, along with other thermoregulatory processes. The word sympathetic means different things in different contexts. ... A synapse is cholinergic if it uses acetylcholine as its neurotransmitter. ... In the anatomy of mammals, the hypothalamus is a region of the brain located below the thalamus, forming the major portion of the ventral region of the diencephalon and functioning to regulate certain metabolic processes and other autonomic activities. ...

Human eccrine sweat is composed chiefly of water with various salts and organic compounds in solution. It contains minute amounts of fatty materials, urea, and other wastes. The concentration of sodium varies from 35 to 65 mmol/l and is lower in people acclimatised to a hot environment. The sweat of other species generally differ in composition. Urea is an organic compound of carbon, nitrogen, oxygen and hydrogen, with the formula CON2H4 or (NH2)2CO and the structure shown right: Urea is also known as carbamide, especially in the recommended International Non-proprietary Names (rINN) in use in Europe. ...

Apocrine sweat glands, which 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. Emotional stress increases the production of sweat from the apocrine glands, or more precisely: the sweat already present in the tubule is squeezed out. Apocrine sweat glands essentially serve as scent glands. Asian people have markedly fewer of these glands compared to white or black people,[[1]] which is why Asian people generally do not emit such odors and foreigners have a reputation among industrialized east Asians as smelling like animals, irrespective of the foreigners' actual hygenic practices. apocrine glands are scent glands. ...

In some areas of the body these sweat glands are modified to produce wholly different secretions, however, including the wax of the outer ear. Others are greatly enlarged and modified to produce milk. Cerumen, commonly known as earwax, is a yellowish, waxy substance secreted in the ear canal of humans and many other mammals. ... A left human ear. ... A glass of cows milk Milk most often means the nutrient fluid produced by the mammary glands of female mammals. ...

See also

• Bromhidrosis
• Diaphoresis
• Hyperhidrosis
• Anhidrosis
• Hyponatremia
• Hyperthermia
• Body odor

Body odor, Bromhidrosis or body odour is the smell of sweat and whatever bacteria are growing on the body. ... Diaphoresis is excessive sweating commonly associated with shock and other medical emergency conditions. ... Primary hyperhidrosis is the condition characterized by abnormally increased perspiration, in excess of that required for regulation of body temperature. ... Anhidrosis means lack of sweating. ... The electrolyte disturbance hyponatremia exists when the sodium level in the plasma falls below 135 mmol/l. ... Hyperthermia, also known as heat stroke or sunstroke, is an acute condition resulting from the body producing or absorbing more heat than it can dissipate, usually due to excessive exposure to heat. ... Body odor, Bromhidrosis or body odour is the smell of sweat and whatever bacteria are growing on the body. ...

References

• Ferner S, Koszmagk R, Lehmann A, Heilmann W., Z Erkr Atmungsorgane. 1990;175(2):70-5. 'Reference values of Na(+) and Cl(-) concentrations in adult sweat'

External link

• Detailed information concerning Hyperhidrosis