Duct (anatomy)

For qualities of writing or speech, see Ductus (linguistics).

Duct
Dissection of a lactating breast. 1 - Fat 2 - Lactiferous duct/lobule 3 - Lobule 4 - Connective tissue 5 - Sinus of lactiferous duct 6 - Lactiferous duct
Section of the human esophagus. Moderately magnified. The section is transverse and from near the middle of the gullet. a. Fibrous covering. b. Divided fibers of longitudinal muscular coat. c. Transverse muscular fibers. d. Submucous or areolar layer. e. Muscularis mucosae. f. Mucous membrane, with vessels and part of a lymphoid nodule. g. Stratified epithelial lining. h. Mucous gland. i. Gland duct. m’. Striated muscular fibers cut across.

In anatomy and physiology, a duct is a circumscribed channel leading from an exocrine gland or organ.

Types of ducts

Examples include:

Duct	From'	To	Carries
Lactiferous duct	mammary gland	nipple	milk
Cystic duct	gallbladder	common bile duct	bile
Common hepatic duct	liver	common bile duct	bile
Common bile duct	common hepatic duct and cystic duct	pancreatic duct	bile
Pancreatic duct	pancreas	hepatopancreatic ampulla	bile and pancreatic enzymes
Ejaculatory duct	vas deferens	urethra	semen
Parotid duct	parotid gland	mouth	saliva
Submaxillary duct	submaxillary gland	mouth	saliva
Major sublingual duct	sublingual gland	mouth	saliva
Bartholin's ducts	Bartholin's glands	Vulva	Bartholin's fluid

Duct system

As ducts travel from the acinus which generates the fluid to the target, the ducts become larger and the epithelium becomes thicker. The parts of the system are classified as follows:

Type of duct	Epithelium	Surroundings
intralobular duct	simple cuboidal	parenchyma
interlobular duct	simple columnar	connective tissue
interlobar duct	stratified columnar	connective tissue

Some sources consider "lobar" ducts to be the same as "interlobar ducts", while others consider lobar ducts to be larger and more distal from the acinus. For sources that make the distinction, the interlobar ducts are more likely to classified with simple columnar epithelium (or pseudostratified epithelium), reserving the stratified columnar for the lobar ducts.

• 

  Section of submaxillary gland of kitten. Duct semidiagrammatic. X 200.

• 

  Section of portion of mamma.

See also

• Ductal carcinoma
• Ductless gland

External links

• duct at eMedicine Dictionary
• Organology at UC Davis termscells&tissues/epithelial/exocrinegland/exocrinegland1 - "Exocrine gland (LM, Low)"
• Overview at uwa.edu.au
• Overview at siumed.edu

This anatomy article is a stub. You can help Wikipedia by expanding it.v · Categories: Anatomy stubs Glands Wikimedia Foundation. 2010. Игры ⚽ Поможем сделать НИР Gregor Benko Estadio La Asunción Look at other dictionaries: Duct — A duct may refer to: Duct (anatomy), various ducts in anatomy and physiology Duct (HVAC), for transfer of air between spaces in a structure Duct tape, a kind of adhesive tape Ducted fan, motor for aircraft Electrical bus duct, a metal enclosure… …   Wikipedia Anatomy — • The science of the form and structure of living beings Catholic Encyclopedia. Kevin Knight. 2006. Anatomy     Anatomy     † …   Catholic encyclopedia Duct of Bellini — Position of the duct of Bellini in the kidney Latin ductus papillaris Gray s …   Wikipedia duct of Santorini — duct of San·to·ri·ni .sant ə rē nē, .sänt n ACCESSORY PANCREATIC DUCT Santorini Giovanni Domenico (1681 1737) Italian anatomist. A professor of anatomy and medicine at Venice, Santorini published major works on anatomy in 1705 and 1724. In the… …   Medical dictionary duct of Wirsung — duct of Wir·sung vir (.)zu̇ŋ, zəŋ n PANCREATIC DUCT (a) Wirsung Johann Georg (1600 1643) German anatomist. A professor of anatomy at Padua, Italy, Wirsung discovered and drew an illustration of the excretory duct of the pancreas in 1642. The… …   Medical dictionary duct of Bellini — duct of Bel·li·ni be lē nē n any of the large excretory ducts of the uriniferous tubules of the kidney that open on the free surface of the papillae Bellini Lorenzo (1643 1704) Italian anatomist and physiologist. Bellini is important as one of… …   Medical dictionary duct — noun a ventilation duct Syn: tube, channel, canal, vessel; conduit, culvert; pipe, pipeline, outlet, inlet, flue, shaft, vent; Anatomy ductus …   Thesaurus of popular words duct — /dʌkt / (say dukt) noun 1. any tube, canal, or conduit by which fluid or other substances are conducted or conveyed. 2. Anatomy, Zoology a tube, canal, or vessel conveying a body fluid, especially a glandular secretion or excretion. 3. Botany a… …   tear duct and glands — ▪ anatomy also called  lachrymal, or lacrimal, duct and glands         structures that produce and distribute the watery component of the tear film. Tears consist of a complex and usually clear fluid that is diffused between the eye (eye, human)… …   Universalium acoustic duct — (Anatomy) external passage of the ear …   English contemporary dictionary 18+ © Academic, 2000-2024 Contact us: Technical Support, Advertising Dictionaries export, created on PHP, Joomla, Drupal, WordPress, MODx. Mark and share Search through all dictionaries Translate… Search Internet Share the article and excerpts Direct link … Do a right-click on the link above and select “Copy Link”