[L. ductus, conveyance (for water)]

1. A narrow tubular vessel or channel, esp. one that conveys secretions from a gland.
2. A narrow enclosed channel containing a fluid, e.g., the semicircular duct of the ear.

accessory pancreatic duct

A duct of the pancreas leading into the main pancreatic duct or into the duodenum at the minor duodenal papilla.
SYN: SEE: duct of Santorini

alimentary duct

SEE: Thoracic duct

alveolar duct

A branch of a respiratory bronchiole that leads directly to the alveolar sacs of the lungs.
SEE: alveolus for illus

Bartholin duct

SEE: Bartholin, Caspar (the younger)

bile duct

Any of the intercellular ducts that convey bile from the liver to the hepatic duct, which joins the duct from the gallbladder (cystic duct) to form the common bile duct (ductus choledochus), and which enters the duodenum about 3 in (7.6 cm) below the pylorus.
SYN: SEE: biliary duct; SEE: ductus choledochusSEE: common bile duct;

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biliary duct

SEE: Bile duct.

Botallo duct

SEE: Ductus arteriosus.

cochlear duct

A short spiral bony canal forming the outer wall of the cochlea within the petrous portion of the temporal bone of the skull.
SYN: SEE: ductus cochlearis; SEE: cochlear canal; SEE: scala media
SEE: cochlea

common bile duct

The duct that carries bile and pancreatic juice to the duodenum. It is formed by the union of the cystic duct of the gallbladder and the hepatic duct of the liver and is joined by the main pancreatic duct.
SYN: SEE: ductus choledochus
SEE: bile duct; SEE: biliary tract for illus

cystic duct

The secretory duct of the gallbladder. It unites with the hepatic duct from the liver to form the common bile duct.
SEE: biliary tract for illus

efferent duct

Any of a group of 12 to 14 small tubes that constitute the efferent ducts of the testis. They lie within the epididymis and connect the rete testis with the ductus epididymidis. Their coiled portions constitute the lobuli epididymidis.

ejaculatory duct

The duct that conveys sperm from the vas deferens and secretions from the seminal vesicle to the urethra.

endolymphatic duct

In the embryo, a tubular projection of the otocyst ending in a blind extremity, the endolymphatic sac. In the adult, it connects the endolymphatic sac with the utricle and saccule of the inner ear.

duct of the epoöphoron

SEE: Gartner duct.
SEE: Gartner, Hermann

excretory duct

Any duct that conveys a waste product from an organ, such as the collecting duct of the renal tubule.

Gartner duct

SEE: Gartner, Hermann

hepatic duct

SEE: left hepatic duct; SEE: right hepatic duct

intercalated duct

Any of several short, narrow ducts that lie between the secretory ducts and the terminal alveoli in the parotid and submandibular glands and in the pancreas.

interlobular duct

A duct passing between lobules within a gland, e.g., one of the ducts carrying bile.

left hepatic duct

The duct that originates in the left lobe of the liver, unites with the right hepatic duct to form the hepatic duct, and drains the left and caudate lobes.

lacrimal duct

Any of the small excretory ducts of the lacrimal glands.

lactiferous duct

Any of 15 to 20 ducts that drain the lobes of the mammary gland. Each opens in a slight depression in the tip of the nipple.
SYN: SEE: milk duct

lymphatic duct

Either of two main ducts conveying lymph to the bloodstream: the left lymphatic (thoracic) and the right lymphatic duct, which drains lymph from the right side of the body above the diaphragm. It discharges into the right subclavian vein. It is smaller than the left lymphatic duct.SEE: thoracic duct;

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main pancreatic duct

The duct that conveys pancreatic juice to the common bile duct and duodenum.
SYN: SEE: duct of Wirsung

mesonephric duct

SEE: Wolffian duct.

milk duct

SEE: Lactiferous duct.

müllerian duct

Either of the bilateral embryonic tubes from which the uterine tubes, uterus, and vagina develop in the female but atrophy in the male.
SYN: SEE: Müller duct

nasolacrimal duct

A membranous duct that runs in the nasolacrimal canal and drains tears from the lacrimal sac to the nasal cavity. It opens beneath the inferior nasal concha.

omphalomesenteric duct

SEE: Vitelline duct

papillary duct

Any of the large ducts formed by the uniting of the collecting tubules of the kidney; it empties into the renal pelvis.

papillary duct of Bellini

SEE: Bellini, Lorenzo

paramesonephric duct

The genital duct in the embryo. In females it develops into the oviducts, uterus, and vagina; in males it degenerates to form the appendix testis.

paraurethral duct

SEE: Skene duct.

parotid duct

The duct leading from the parotid gland to the oral cavity.
SYN: SEE: Stensen duct

prostatic duct

One of about 20 ducts that discharge prostatic secretion into the urethra.
SYN: SEE: ductus prostaticus

right hepatic duct

The duct that originates in the right lobe of the liver, unites with the left hepatic duct to form the hepatic duct, and drains the right right and caudate lobes.

duct of Rivinus

SEE: Rivinus, August

salivary duct

Any of the ducts that drain a salivary gland.

duct of Santorini

SEE: Accessory pancreatic duct.

secretory duct

Any of the smaller ducts of a gland.

segmental duct

One of a pair of embryonic ducts located between the visceral and parietal layers of the mesoblast on each side of the body.

semicircular duct

One of three membranous ducts forming a part of the vestibular labyrinth of the inner ear. They lie within the semicircular canals and bear corresponding names: anterior, posterior, and lateral. The semicircular ducts originate from the utricle as a single common tube (crus communale). The three ducts then branch, and each follows the course of a different bony semicircular canal. At their far ends the ducts widen into an ampulla that contains a specialized endothelium that is sensitive to motion of the endolymph. Axons from receptor cells in these sensory epithelia transmit motion information to the brain via the vestibular division of the vestibulococchlear nerve (CN VIII).
SEE: labyrinth for illus.

seminal duct

Any of the ducts that convey sperm, specifically the ductus deferens and the ejaculatory duct.

Skene duct

SEE: Skene, Alexander

spermatic duct

The secretory duct of the testicle that later joins the duct of the seminal vesicle to become the ejaculatory duct.
SYN: SEE: ductus deferens; SEE: vas deferens; SEE: testicular duct

Stensen duct

SEE: Stensen, Niels

striated duct

Any of a class of ducts within the lobules of glands, esp. salivary glands, that contain radially appearing striations within the cells, denoting the presence of mitochondria.

sublingual duct

Any of the secretory ducts of the sublingual gland.
SEE: Bartholin duct

tear duct

A duct that conveys tears. These include secretory ducts of lacrimal glands, and lacrimal and nasolacrimal ducts.

testicular duct

SEE: Spermatic duct.

thoracic duct

The main lymphatic duct, originating at the cisterna chyli. It passes upward through the diaphragm into the thorax and continues upward along the aorta and esophagus to the neck, where it turns to the left and enters the left subclavian vein near its junction with the left internal jugular vein. It receives lymph from all parts of the body except the right side of the head, neck, thorax, and upper extremity.
SYN: SEE: alimentary duct
SEE: lymphatic system for illus

thyroglossal duct

In the embryo, a duct that connects the thyroid diverticulum with the tongue. It sometimes persists as a postpartum anomaly, most often in the form of thyroglossal duct cysts.

umbilical duct

SEE: Vitelline duct

utriculosaccular duct

A narrow duct emanating from the utricle, connecting it to the saccule, and opening into the endolymphatic duct of the inner ear.
SYN: SEE: ductus utriculosaccularis

vitelline duct

The duct that connects the embryonic gut to the yolk sac. It disappears during fetal development.
SYN: SEE: omphalomesenteric duct; SEE: umbilical duct; SEE: yolk stalk

wolffian duct

In the embryo, the duct leading from the mesonephros to the cloaca. From it develops the ductus epididymis, ductus deferens, seminal vesicle, ejaculatory duct, ureter, and pelvis of the kidney.
SYN: SEE: mesonephric duct.