| ampulla of milk duct | A circumscribed spindle-shaped dilation of the lactiferous duct just before it enters the nipple. In nursing mothers this dilatation stores a droplet of milk which is expressed by compression as the infant begins to suckle; this is thought to encourage continual suckling while the let-down reflex ensues. Synonym: sinus lactiferi, ampulla lactifera, ampulla of milk duct, lactiferous ampulla. (05 Mar 2000) |
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| arch of thoracic duct | See: thoracic duct. (05 Mar 2000) |
| arterial duct | Before birth, the blood headed from the heart (via the pulmonary artery) for the lungs is shunted away from the lungs and returned to the greatest of arteries (the aorta). The shunt is through a short vessel called the ductus arteriosus. When the shunt is open, it is said to be patent (pronounced pa'tent). The patent ductus arteriosus (PDA) usually closes at or shortly after birth and blood is permtted from that moment on to course freely to the lungs. If the ductus stays open (patent), flow reverses and blood from the aorta is shunted into the pulmonary artery and recirculated through the lungs. The PDA may close later spontaneously (on its own) or need to be ligated (tied off) surgically. (12 Dec 1998) |
| Bartholin's duct | The duct that drains the anterior portion of the sublingual gland; it opens at the sublingual papilla. Synonym: ductus sublingualis major, Bartholin's duct. (05 Mar 2000) |
| basal lamina of saemicircular duct | The basal membrane underlying the epithelium of the saemicircular duct. Synonym: membrana basalis ductus saemicircularis, basal lamina of saemicircular duct. (05 Mar 2000) |
| basal membrane of saemicircular duct | The basal membrane underlying the epithelium of the saemicircular duct. Synonym: membrana basalis ductus saemicircularis, basal lamina of saemicircular duct. (05 Mar 2000) |
| basilar crest of cochlear duct | An inward projection of the spiral ligament of the cochlea to which is attached the basilar membrane forming the floor of the cochlear duct. Synonym: crista basilaris ductus cochlearis. (05 Mar 2000) |
| Bernard's duct | The excretory duct of the head of the pancreas, one branch of which joins the pancreatic duct, the other opening independently into the duodenum at the lesser duodenal papilla. Synonym: ductus pancreaticus accessorius, Bernard's canal, Bernard's duct, ductus dorsopancreaticus, Santorini's canal, Santorini's duct. (05 Mar 2000) |
| biliary duct | <anatomy> A duct that carries bile from the liver and gallbladder to the duodenum (first part of the small intestine). (27 Sep 1997) |
| Blasius' duct | The duct of the parotid gland opening from the cheek into the vestibule of the mouth opposite the neck of the superior second molar tooth. Synonym: ductus parotideus, Blasius' duct, Stensen's duct, Steno's duct. (05 Mar 2000) |
| blocked tear duct | A blocked nasolacrimal duct which normally carries tears from the eyes to the nose. Commonly seen in infants, but usually resolves spontaneously by age 2-3. In adults blockage can occur from chronic sinusitis or trauma. A gentle massage of the lacrimal gland 2-3 times a day for several months may reopen the tear duct. (27 Sep 1997) |
| blunt duct adenosis | Adenosis of the breast in which the ducts are enlarged but not increased in number. (05 Mar 2000) |
| Botallo's duct | Before birth, the blood headed from the heart (via the pulmonary artery) for the lungs is shunted away from the lungs and returned to the greatest of arteries (the aorta). The shunt is through a short vessel called the ductus arteriosus. When the shunt is open, it is said to be patent (pronounced pa'tent). The patent ductus arteriosus (PDA) usually closes at or shortly after birth and blood is permtted from that moment on to course freely to the lungs. If the ductus stays open (patent), flow reverses and blood from the aorta is shunted into the pulmonary artery and recirculated through the lungs. The PDA may close later spontaneously (on its own) or need to be ligated (tied off) surgically. (12 Dec 1998) |
| bucconeural duct | The slender tubular part of the hypophysial diverticulum; the stalk of Rathke's pocket. Synonym: bucconeural duct, hypophysial duct. (05 Mar 2000) |
| carcinoma, infiltrating duct | An invasive (infiltrating) carcinoma of the breast. This carcinoma in which no special histological feature is recognised is designated nos or not otherwise specified and is by far the most common ductal tumour, accounting for almost 70% of breast cancers. It is characterised by stony hardness upon palpation. It commonly metastasizes to the axillary lymph nodes and its prognosis is the poorest of the various ductal types. (12 Dec 1998) |