Sweat Glands


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Sweat Glands

 

simple, usually unbranched tubular glands of the skin in man and mammalian animals (except moles, pangolins, sloths, some pinnipeds, whales, and Sirenia) that produce and excrete sweat.

The total number of sweat glands in man is from 2 to 5 million. Their number and size vary in different parts of the body. There are many sweat glands in the skin of the finger and toe pads, palms and soles, and axial and inguinal folds (average, from 150 to 339; on the skin of the palm up to 1,000 sweat glands per sq cm). The sweat glands of mammals are derivatives of multicellular glands of the integuments of amphibians, since both kinds are lined with smooth musculature of ectodermal origin— myoepithelial cells. The saclike untwisted shape of sweat glands is characteristic of primitive mammals, such as marsupials.

The sweat glands consist of an unbranched excretory duct and an acinus, which, like the beginning of the excretory duct, is rolled in a ball located on the boundary between the reticular layer of the skin and the subcutaneous tissue. The excretory ducts open through apertures, or sweat pores, to the surface of the skin, and on hairy parts of the body usually into the hair follicles. The secretory section consists of a single layer of prismatic cells with tiny vacuoles, droplets of fat, and granules of glycogen and pigment. The appended myoepithelial cells, which excrete sweat by their contractions, are located on the basal membrane.

Sweat glands are classified according to type of secretion as ordinary merocrine glands, which are most highly developed among humans and primates, and specific apocrine glands of the majority of mammals. The special varieties of sweat glands of the eyelids and of the ears produce cerumen. In old age the number of sweat glands in man diminishes, and their secretory section is curtailed. The sweat glands are innervated by sympathetic nerves, whose endings secrete acetylcholine when they are stimulated— that is, they are cholinergic, as are the parasympathetic nerves. By producing a large quantity of sweat, the sweat glands regulate heat emission; excrete the products of nitrogen metabolism and salts of alkaline metals, mainly sodium chloride; and moisten the surface of the skin.

REFERENCE

Shmal’gauzen, I. I. Osnovy sravnitel’noi anatomii pozvonochnykh zhivotnykh, 4th ed. Moscow, 1947.
Gistologiia, 2nd ed. Edited by V. G. Eliseev et al. Moscow, 1972.
Sokolov, V. E. Kozhnyi pokrov mlekopitaiushchikh. Moscow, 1973.
References in periodicals archive ?
Botox can (https://www.healthline.com/health/bromhidrosis#treatment) freeze the muscles in the underarm and block the nerves from sending impulses to the sweat glands. This treatment is temporary and may have to be repeated a few times throughout the year.
Poor blood circulation, inefficient sweat glands, high blood pressure and some medications (e.g., diuretics, tranquilizers) can reduce sweating.
Botox injected into sweat glands decreases both sweating and odor.
Previously, studies have demonstrated that eccrine sweat glands are innervated by both cholinergic and adrenergic nerves, with cholinergic nerves playing the primary roles.[1],[9] However, it is unknown whether the secretory coils and ducts of eccrine sweat glands are equally innervated by the sympathetic nerve fibers.
Keywords: Hidradenoma, Nodular, Sweat gland, Tumour, Ultrasound.
Malignant acrospiroma is a rare tumour of the eccrine sweat glands, that usually displays an aggressive behaviour.
The sweat produced by the eccrine sweat glands is mostly water, which helps to cool the body down.
The sweat glands in buffaloes were of saccular and simple coiled tubular type (Figures 5, 6, 7, 8, and 10).
The majority of the sweat glands in our skin are "eccrine." These are responsible for most of our heat- and exercise-related sweating and secrete an odorless, clear fluid (made mostly of water and salt) to help control temperature by promoting heat loss through evaporation.
If that doesn't work, your GP may refer you for an injection of the Botulinum toxin, which temporarily reduces sweating by blocking signals from the brain to the sweat glands.