Editing Sweat gland (section)

==Types==

===Eccrine===
{{main|Eccrine sweat gland}}
Eccrine sweat glands are everywhere except the lips, [[ear canal]], [[foreskin]], [[glans penis]], [[labia minora]], [[clitoral hood]], and [[clitoris]]. They are ten times smaller than apocrine sweat glands, do not extend as deeply into the dermis, and excrete directly onto the surface of the skin.{{sfn|Kurosumi|Shibasaki|Ito|1984|p=255}}{{sfn|Krstic|2004|p=466}}<ref name=spearman73>{{cite book| publisher = CUP Archive| isbn = 9780521200486| volume = 3| last = Spearman| first = Richard Ian Campbell| title = The Integument: A Textbook For Skin Biology| series = Biological Structure and Function Books| year = 1973| page = [https://archive.org/details/integumenttextbo00spea/page/135 135]| url = https://archive.org/details/integumenttextbo00spea/page/135}}</ref>{{sfn|Krstic|2004|p=464}} The proportion of eccrine glands decreases with age.{{sfn|Wilke|Martin|Terstegen|Biel|2007|pp=175–176}}

The clear secretion produced by eccrine sweat glands is termed [[sweat]] or ''sensible perspiration''. Sweat is mostly water, but it does contain some [[electrolyte]]s, since it is derived from [[blood plasma]]. The presence of [[sodium chloride]] gives sweat a salty taste.

The total volume of sweat produced depends on the number of functional glands and the size of the surface opening. The degree of secretory activity is regulated by neural and hormonal mechanisms (men sweat more than women). When all of the eccrine sweat glands are working at maximum capacity, the rate of perspiration for a human being may exceed three liters per hour,<ref>{{cite book|first1=Cleveland P. Jr.|last1=Hickman|first2=Larry S.|last2=Roberts|first3=Allan|last3=Larson|title=Integrated principles of zoology|date=April 2003|publisher=McGraw-Hill|location=Boston|isbn=9780072439403|edition=12th|page=[https://archive.org/details/isbn_9780072930283/page/634 634]|url=https://archive.org/details/isbn_9780072930283/page/634}}</ref> and dangerous losses of fluids and electrolytes can occur.

Eccrine glands have three primary functions:
* Thermoregulation: sweat (through [[evaporation]] and evaporative heat loss) can lead to cooling of the surface of the skin and a reduction of body temperature.{{sfn|Wilke|Martin|Terstegen|Biel|2007|p=170}}
* Excretion: eccrine sweat gland secretion can also provide a significant excretory route for water and electrolytes.{{sfn|Romich|2009|p=203}}
* Protection: eccrine sweat gland secretion aids in preserving the skin's [[acid mantle]], which helps protect the skin from colonization from bacteria and other pathogenic organisms.<ref>{{cite book | last=Marples|first= Mary J. | title=The ecology of the human skin | year=1965|publisher= Thomas | ol=5915977M|isbn=9780398012182}}</ref>

===Apocrine===
{{main|Apocrine sweat gland}}

Apocrine sweat glands are found in the armpit, [[areola]] (around the nipples), perineum (between the anus and genitals), in the ear, and the eyelids. The secretory portion is larger than that of eccrine glands (making them larger overall). Rather than opening directly onto the surface of the skin, apocrine glands secrete sweat into the pilary canal of the [[hair follicle]].{{sfn|Kurosumi|Shibasaki|Ito|1984|p=255}}

Before puberty, the apocrine sweat glands are inactive;<ref name=mosby /> [[Puberty#Major hormones|hormonal changes in puberty]] cause the glands to increase in size and begin functioning.<ref name=braunfalco>{{cite book| publisher = Springer Berlin Heidelberg| isbn = 978-3-642-97933-0| pages = 1083–1086| last1 = Braun-Falco| first1 = Otto| first2 = Gerd|last2= Plewig|first3=Helmut H.|last3= Wolff|first4=Walter H. C. |last4=Burgdorf| title = Dermatology| chapter = Diseases of the Apocrine Sweat Glands| date = 1 January 2000}}</ref> The substance secreted is thicker than eccrine sweat and provides nutrients for bacteria on the skin: the bacteria's decomposition of sweat is what creates the acrid odor.<ref name=dorlands /> Apocrine sweat glands are most active in times of stress and sexual excitement.<ref name=americanheritage />

In mammals (including humans), apocrine sweat contains [[pheromone]]-like compounds to attract other organisms within their species. Study of human sweat has revealed differences between men and women in apocrine secretions and bacteria.<ref>{{cite web| last1 = Currie| first1 = Ariel| first2 = Hank| last2 = Coshnear| first3 = Mila| last3 = Quinn| first4 = Logan| last4 = Sand| publisher = Macalaster College| title = Human Pheromones| access-date = 6 June 2013| url = http://www.macalester.edu/psychology/whathap/UBNRP/pheromone10/human%20pheromones.html| archive-url = https://web.archive.org/web/20130512060404/http://www.macalester.edu/psychology/whathap/UBNRP/pheromone10/human%20pheromones.html| archive-date = 12 May 2013| url-status = dead}}</ref>

===Apoeccrine===
Some human sweat glands cannot be classified as either apocrine or eccrine, having characteristics of both; such glands are termed ''apoeccrine''.{{sfn|Wilke|Martin|Terstegen|Biel|2007|p=171}} They are larger than eccrine glands, but smaller than apocrine glands.<ref>{{cite book|editor-last=Cooper|editor-first=Grant|title=Therapeutic Uses of Botulinum Toxin|url=https://archive.org/details/therapeuticusesb00coop_467|url-access=limited|year=2007|publisher=Humana Press|location=Totowa, N.J.|isbn=9781597452472|page=[https://archive.org/details/therapeuticusesb00coop_467/page/n157 155]}}</ref> Their secretory portion has a narrow portion similar to secretory coils in eccrine glands as well as a wide section reminiscent of apocrine glands.<ref>{{cite book | publisher=KARGER | isbn=978-3-8055-7306-1 | volume=30 | pages=1–9 |editor1=Kreyden, O.P. |editor2=Burg, G. | last=Böni | first=R. |author2=Groscurth, P. | title=Current Problems in Dermatology | chapter=Anatomy of Sweat Glands | location=Basel | year=2002 | chapter-url=http://www.karger.com/Article/PDF/60678}}</ref>

Apoeccrine glands, found in the armpits and perianal region, have ducts opening onto the skin surface.<ref>{{cite book | publisher=Karger Publishers | isbn=978-3805573061 | last=Kreyden | first=Oliver Philip |author2=Böni, Roland Emil |author3=Burg, Günter | title=Hyperhidrosis and Botulinum Toxin in Dermatology: 18 Tables | year= 2002|page=8}}</ref> They are presumed to have developed in puberty from the eccrine glands,{{sfn|Wilke|Martin|Terstegen|Biel|2007|p=175}} and can comprise up to 50% of all axillary glands. Apoeccrine glands secrete more sweat than both eccrine and apocrine glands, thus playing a large role in axillary sweating.{{sfn|Wilke|Martin|Terstegen|Biel|2007|p=176}} Apoeccrine glands are sensitive to cholinergic activity, though they can also be activated via adrenergic stimulation.{{sfn|Wilke|Martin|Terstegen|Biel|2007|p=171}} Like eccrine glands, they continuously secrete a thin, watery sweat.{{sfn|Wilke|Martin|Terstegen|Biel|2007|p=176}}

===Others===

Specialized sweat glands, including the [[ceruminous gland]]s, [[mammary gland]]s, ciliary glands of the eyelids, and sweat glands of the [[nasal vestibule|nasal vestibulum]], are modified apocrine glands.<ref name=hogin06>{{cite book| publisher = Sterling Publishing Company, Inc.| isbn = 9781402737886| last = McMurtrie| first = Hogin| title = McMurtrie's Human Anatomy Coloring Book: A Systemic Approach to the Study of the Human Body: Thirteen Systems| date = 28 November 2006|page=430}}</ref>{{sfn|Krstic|2004|p=466}} Ceruminous glands are near the ear canals, and produce cerumen (earwax) that mixes with the oil secreted from [[sebaceous glands]].{{sfn|Romich|2009|p=206}}<ref name=hogin06 /> Mammary glands use apocrine secretion to produce milk.<ref name=vanlommel />