| 释义 |
DictionarySeeyolk stalkvitelline duct
vitelline duct[vī′tel‚ēn ′dəkt] (embryology) The constricted part of the yolk sac opening into the midgut region of the future ileum. Also known as omphalomesenteric duct; umbilical duct. vitelline duct
yolk stalkthe narrowed connection between the intraembryonic gut and the yolk sac; its walls are splanchnopleure. Synonym(s): omphaloenteric duct, ophaloenteric duct, umbilical duct, vitelline duct, vitellointestinal ductduct (dukt) [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 ductA duct of the pancreas leading into the pancreatic duct or the duodenum near the mouth of the common bile duct. Synonym: duct of Santorinialimentary ductAn obsolete term for the thoracic duct. alveolar ductA branch of a respiratory bronchiole that leads directly to the alveolar sacs of the lungs. See: alveolus for illusBartholin duct See: Bartholin, Caspar (the younger) BILE DUCTSbile ductAny of the intercellular passages 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. Synonym: biliary duct See: illustrationbiliary ductBile duct.Botallo ductDuctus arteriosus.cochlear ductCochlear spiral canal.common bile ductThe 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. Synonym: ductus choledochus See: biliary tract for illuscystic ductThe 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 ductAny 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 ductThe duct that conveys sperm from the vas deferens and secretions from the seminal vesicle to the urethra. endolymphatic ductIn 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 epoophoronGartner's duct.excretory ductAny duct that conveys a waste product from an organ, such as the collecting duct of the renal tubule.Gartner duct See: Gartner, Hermannhepatic ductEither of the ducts that receive bile from the right or left lobe of the liver and carries it to the common bile duct. Synonym: ductus hepaticus dexter; ductus hepaticus sinisterintercalated ductAny 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 ductA duct passing between lobules within a gland, e.g., one of the ducts carrying bile.lacrimal ductAny of the small excretory ducts of the lacrimal glands.lactiferous ductAny 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. Synonym: milk duct DRAINAGE AREAS FOR LYMPHATIC DUCTSlymphatic ductEither 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; illustrationmesonephric ductWolffian duct.milk ductLactiferous duct.müllerian ductEither of the bilateral embryonic tubes in the embryo from which the oviducts, uterus, and vagina develop in the female; in the male, they atrophy. Synonym: Müller ductnasolacrimal ductA membranous tube 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 ductYolk stalk.pancreatic ductThe duct that conveys pancreatic juice to the common bile duct and duodenum. Synonym: duct of Wirsungpapillary ductAny 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, Lorenzoparamesonephric ductThe genital canal in the embryo. In females it develops into the oviducts, uterus, and vagina; in males it degenerates to form the appendix testis. paraurethral ductSkene duct.parotid ductStensen duct.prostatic ductOne of about 20 ducts that discharge prostatic secretion into the urethra. Synonym: duct prostaticusduct of Rivinus See: Rivinus, Augustsalivary ductAny of the ducts that drain a salivary gland. duct of SantoriniAccessory pancreatic duct.secretory ductAny of the smaller canals of a gland. segmental ductOne of a pair of embryonic tubes located between the visceral and parietal layers of the mesoblast on each side of the body.semicircular ductOne of three membranous tubes 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 ductAny of the ducts that convey sperm, specifically the ductus deferens and the ejaculatory duct.Skene duct See: Skene, Alexanderspermatic ductThe secretory duct of the testicle that later joins the duct of the seminal vesicle to become the ejaculatory duct. Synonym: ductus deferens; vas deferens; testicular ductStensen duct See: Stensen, Nielsstriated ductAny 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 ductAny of the secretory ducts of the sublingual gland. See: Bartholin ducttear ductA duct that conveys tears. These include secretory ducts of lacrimal glands, and lacrimal and nasolacrimal ducts. testicular ductSpermatic duct.thoracic ductThe 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. See: lymphatic system for illus thyroglossal ductIn the embryo, a duct that connects the thyroid diverticulum with the tongue. It eventually disappears, its point of origin being indicated as a pit, the foramen cecum. It sometimes persists as an anomaly. umbilical ductYolk stalk.utriculosaccular ductA narrow tube emanating from the utricle, connecting it to the saccule, and opening into the endolymphatic duct of the inner ear.vitelline ductYolk stalk.wolffian ductIn the embryo, the duct leading from the mesonephros to the cloaca. From it develop the ductus epididymis, ductus deferens, seminal vesicle, ejaculatory duct, ureter, and pelvis of the kidney. Synonym: mesonephric ductvitelline duct the duct which conveys yolk from the yolk gland to the oviduct.ThesaurusSeeduct |