Exocrine gland 72672 222018429 2008-06-27T04:37:31Z 202.164.158.188 /* Types */ {{Refimprove|date=September 2007}} {{Expand|article|date=March 2007}} {{Cleanup|date=March 2007}} {{Infobox Anatomy | Name = Exocrine gland | Latin = | GraySubject = | GrayPage = | Image = Gray1026.png | Caption = Human submaxillary gland. At the right is a group of mucous alveoli, at the left a group of serous alveoli.| Image2 = | Caption2 = | System = | MeshName = | MeshNumber = | DorlandsPre = | DorlandsSuf = | }} '''Exocrine glands''' are [[gland]]s that secrete their products ([[enzyme]]s) into [[duct (anatomy)|duct]]s (duct glands). They are the counterparts to [[endocrine glands]], which secrete their products ([[hormone]]s) directly into the [[blood]]stream (ductless glands) or release hormones ([[paracrine]]s) affect only target cell nearby the release site. ==Examples== Typical exocrine glands include [[sweat gland]]s, [[salivary gland]]s, [[mammary gland]]s, [[stomach]], [[liver]] and the [[pancreas]]. (Example of an endocrine gland is the adrenal gland, which is found on top of the kidneys and secretes the hormone adrenaline). ==Types== There are many ways of classifying exocrine glands: ===Structure=== Exocrine glands contain a glandular portion and a duct portion, the structures of which can be used to classify the gland. * The duct portion may be branched (called ''compound'') or unbranched (called ''simple''). * The glandular portion may be tubular, [[acinus|acinar]], or may be a mix of the two (called tubuloacinar). If the glandular portion branches, then the gland is called a branched gland. ===Method of secretion=== Exocrine glands are named [[apocrine]] gland, [[holocrine]] gland, or [[merocrine]] gland based on how their product is secreted. *'''Apocrine glands''' - a portion of the plasma membrane buds off the cell, containing the secretion. ''Apocrine gland'' is often used to refer to the [[apocrine sweat glands]] which use merocrine secretion. *'''Holocrine glands''' - the entire cell disintegrates to secrete its substance. *'''Merocrine glands''' - cells secrete their substances by [[exocytosis]]. Also called "eccrine." ===Product secreted=== * Serous cells secrete [[protein]]s, often [[enzyme]]s. Examples include [[chief cells]] and [[Paneth cells]] * Mucous cells secrete [[mucus]]. Examples include [[Brunner's glands]], [[esophageal glands]], and [[pyloric glands]] * Mixed glands secrete both protein and mucus. Examples include the [[salivary glands]], although [[parotid gland]] is predominantly serous, the [[sublingual gland]] is predominantly mucous and the submandibular gland is both serous and mucous. ==List of exocrine glands== Glands typically may be referred to by two or more means, though some terms are rarely seen. The names of the [[anatomist]]s who first described them are often employed, as: {| class="sortable wikitable" | '''name(s)''' || '''location''' || '''product''' || '''structure''' |- | [[apocrine sweat glands]] || [[skin]] || - || coiled tubular |- | [[Bartholin's glands]], Tiedmann's glands, vulvovaginal glands || [[vulva]], [[vagina]] || - || - |- | [[anterior lingual glands|Bauhin's glands]], anterior lingual glands || [[tongue]], near tip || nonserous or mixed || - |- | [[Brunner's glands]], duodenal glands || [[duodenum]] || mucous || compound tubular |- | [[bulbourethral glands]], Cowper's glands, Mery's glands || [[penis]], base || - || - |- | [[Ciaccio's glands]], accessory [[lacrimal glands]] || [[eye]] || - || - |- | [[Cobelli's glands]] || [[esophagus]], just above the [[cardia]], in the [[mucosa]] || mucous || - |- | [[Duverney's gland]] || [[vagina]], on either side || - || - |- | [[Ebner's glands]] || [[tongue]] || serous || - |- | [[eccrine sweat glands]] || [[skin]] || - || coiled tubular |- | [[esophageal glands]] || [[esophagus]] || mucous || racemose |- | [[exocrine pancreas]] || [[pancreas]] || serous || tubulo-acinar |- | [[Fränkel's glands]] || [[vocal cords]], below the edge || - || - |- | [[gastric chief cell]], Wasmann's glands || [[stomach]] || serous || - |- | [[glomus coccygeum]], coccygeal gland, Luschka's gland or ganglion || [[coccyx]], near the tip || - || - |- | [[goblet cells]] || [[digestive tract]], [[respiratory tract]] || mucous || simple unicellular |- | [[Crypts of Henle|Henle's glands]] || [[eyelids]], in the [[conjuctiva]] || - || tubular |- | [[Huguier's glands]] || [[vagina]] || - || - |- | [[Krause's glands]] || [[conjunctiva]], middle portion || mucous || - |- | [[Lieberkuhn's gland]]s || [[intestines]], surface of [[mucous membrane]] || - || simple tubular |- | [[Littré's glands]], Morgagni's glands || [[spongy portion of the urethra]] || - || [[racemose]] |- | [[mammary gland]] || [[breast]] || - || compound tubulo-acinar |- | [[Meibomian gland]] || [[eyelids]] || sebaceous || - |- | [[Glands of Moll|Moll's glands]] || [[eyelids]] || - || - |- | [[Montgomery's glands]] || mammary [[areola]] || sebaceous || - |- | [[Naboth's glands]] || [[cervix]] and [[os uteri]] || mucous || - |- | [[olfactory glands]], Bowman's glands || [[nose]], [[olfactory]] region || - || - |- | [[Paneth cells]] || [[small intestine]] || serous || - |- | [[parathyroid glands]], Gley's glands, Sandstroem's glands || [[thyroid]], on surface || - || - |- | [[parotid gland]] || [[mouth]] || serous || tubulo-alveolar |- | [[Peyer's patches]] (or glands) || [[ileum]], [[lymphatic]] glands || - || - |- | [[pyloric glands]] || [[stomach]] || mucous || simple branched tubular |- | [[sebaceous gland]] || [[skin]] || sebum || acinar - branched |- | [[Skene's glands]], Guérin's glands || [[vagina]] || - || - |- | [[sublingual gland]], Rivini's gland || [[mouth]] || mucus (primarily) || tubulo-alveolar |- | [[submandibular gland]] || [[mouth]] || mixed (M+S) || tubulo-alveolar |- | [[sudoriparous glands]], Boerhaave's glands || [[skin]] || - || - |- | [[Sigmund's glands]] || [[epitrochlear]] [[lymph node]]s || - || - |- | [[Suzanne's gland]] || mouth, beneath the [[alveolingual]] groove || mucous || - |- | [[Weber's glands]] || [[tongue]] || mucous || tubular |- | [[Glands of Zeis]] || [[eyelids]], free edges || sebaceous || - |} ==See also== * [[Wikipedia:MeSH A10#MeSH A10.336 --- exocrine glands]] Prostate gland is an exocrine gland of the male mammalian reproductive system. It secretes a clear and basic fluid that constitutes 1/3 of the volume of semen. ==Additional images== <gallery> Image:Gray1033.png|Section of the human esophagus. Moderately magnified. Image:Gray1172.png|Dissection of a lactating breast. </gallery> ==References== {{reflist}} ==External links== * [http://www.mhhe.com/biosci/ap/histology_mh/glands.html Diagram at mhhe.com] * {{eMedicineDictionary|gland}} {{Glands}} [[Category:Glands]] [[Category:Integumentary system]] [[ar:غدة قنوية]] [[de:Exokrine Drüse]] [[es:Glándula exocrina]] [[fr:Glande exocrine]] [[is:Útkirtietethhethetll]] [[he:בלוטה אקסוקרינית]] [[ja:外分泌腺]] [[pt:Glândula exócrina]] [[ru:Железа внешней секреции]] [[sl:Žleza z zunanjim izločanjem]]