Exocrine gland

Exocrine gland
Human submaxillary gland. At the right is a group of mucous alveoli, at the left a group of serous alveoli.
Identifiers
MeSH	D005088
TH	H2.00.02.0.03014
FMA	9596
Anatomical terminology

Exocrine glands are glands that secrete their products (enzymes) into ducts (duct glands). They are the counterparts to endocrine glands, which secrete their products (hormones) directly into the bloodstream (ductless glands).

Examples

Typical exocrine glands include sweat glands, salivary glands, mammary glands, stomach, liver and the pancreas.

Types

There are multiple 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, 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 proteins, often enzymes. 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, and sublingual gland is predominantly 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 anatomists who first described them are often employed, as:

name(s)	location	product	structure
apocrine sweat glands	skin	-	coiled tubular
Bartholin's glands, Tiedmann's glands, vulvovaginal glands	vulva, vagina	-	-
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
Henle's glands	eyelids, in the conjuctiva	-	tubular
Huguier's glands	vagina	-	-
Krause's glands	conjunctiva, middle portion	mucous	-
Lieberkuhn's glands	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	-
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 nodes	-	-
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

• 
  Section of the human esophagus. Moderately magnified.
• 
  Dissection of a lactating breast.

References

• Diagram at mhhe.com
• Template:EMedicineDictionary
• Anatomy photo: termscells&tissues/epithelial/exocrinegland/exocrinegland - Comparative Organology at University of California, Davis - "Exocrine gland (LM, Low)"