Sweating is the secretion of fluid by sweat glands in the body (1).
There are two types of sweat glands in the body:
Eccrine glands are found on the entire surface of the body. Nerve impulses cause a discharge of a drop onto the skin surface. The sweat from these glands is mainly water containing certain salts, mainly sodium chloride, lactic acid and ammonia. (2,3)
Apocrine glands are mainly in the armpit, outer ear, groin, around the nipples, genitals and anus. These are larger glands which are set deeper in the skin. They secrete the sweat into the hair follicles found above the sebaceous glands. The secretion of these sweat glands is mainly proteins, carbohydrates and salts.
A person weighing 70 kg can secrete half a liter of perspiration a day and up to a liter an hour in hot weather.
Glandular secretion is sterile (free of risk factors)and in fact has no smell (1,2,3)
The characteristic smell of perspiration is caused by bacteria that reside on the skin, especially around the armpit glands that secrete proteins and carbohydrates used as food by the bacteria.
The function of sweat glands
Sweat glands are used to balance body temperature and protect the body from overheating. When body temperature rises because of physical effort or environmental temperature, sweat glands secrete sweat on cue from the nervous system. The sweat evaporates off the body into the air while “stealing” heat from the body and thus lowering the body temperature. There are also mental states such as anxiety and irritability that cause perspiration regardless of temperature.
Secretion of sweat glands allows not only body temperature balancing but also secretion of various pollutants such as metals, salts and urea from the body. Therefore perspiration is important to the metabolism of the body. In the following article I shall write about the importance of perspiration in the different doctrines.
Posted by: Ido Mashaal: (BA biology. B. Sc – Chemical Engineering, M.Sc. – Materials Engineering (Technion))
1. Family Health Encyclopedia Carta, 1999, Carta, Jerusalem.
2. Sweat – wikipedia free encyclopedia – www.he.wikipedia.org/wiki/ sweat
3. Perspiration – wikipedia – Http://en.wikipedia.org/wiki/Perspiration