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congenital absence or closure of a normal body opening or tubular structure; see also obstruction. adj., adj atret´ic.
anal atresia (atresia a´ni) imperforate anus.
1. congenital absence of the aortic orifice.
2. absence or closure of the aortic orifice, a rare congenital anomaly in which the left ventricle is hypoplastic, so that oxygenated blood passes from the left into the right atrium through a septal defect, and the mixed venous and arterial blood passes from the pulmonary artery to the aorta by way of a patent ductus arteriosus.
aural atresia absence of closure of the auditory canal.
biliary atresia congenital obliteration or hypoplasia of one or more components of the bile ducts, resulting in persistent jaundice and liver damage.
choanal atresia blockage of the posterior nares. When the blockage is bilateral in a newborn, it produces acute respiratory distress because neonates are nose-breathers. Diagnosis is confirmed if a catheter cannot be passed through the nares. Until surgery is done to relieve the obstruction, insertion of an airway may be necessary.
esophageal atresia congenital lack of continuity of the esophagus, commonly accompanied by tracheoesophageal fistula, and characterized by accumulations of mucus in the nasopharynx, gagging, vomiting when fed, cyanosis, and dyspnea. Treatment should begin with suction of the upper esophageal pouch, followed by surgical repair by esophageal anastomosis and division of the fistula as soon as the infant's general condition permits.
follicular atresia (atresia folli´culi) the normal death of the ovarian follicle when unfertilized.
laryngeal atresia congenital lack of the normal opening into the larynx.
mitral atresia congenital obliteration of the mitral orifice; it is associated with hypoplastic left heart syndrome and transposition of great vessels.
prepyloric atresia congenital membranous obstruction of the gastric outlet, characterized by vomiting of gastric contents only. Called also pyloric atresia.
pulmonary atresia congenital severe narrowing or obstruction of the pulmonary orifice, with cardiomegaly, reduced pulmonary vascularity, and right ventricular atrophy. It is usually associated with tetralogy of fallot, transposition of great vessels, or other cardiovascular anomalies.
pyloric atresia prepyloric atresia.
tricuspid atresia absence of the tricuspid orifice, circulation being made possible by an atrial septal defect.
urethral atresia imperforation of the urethra.
congenital absence of the valvular orifice into the aorta.
Etymology: Gk, aeirein + a, tresis, a boring
a congenital anomaly in which the left side of the heart is defective and there is an imperforation of the aortic valve into the aorta.
a·or·tic a·tre·sia(ā-ōr'tik ă-trē'zē-ă)
Congenital absence of the normal valvular orifice into the aorta.
congenital absence or closure of a normal body opening or tubular structure.
anal atresia, atresia ani
see anal atresia.
absence of the opening from the left ventricle of the heart into the aorta.
absence of closure of the auditory canal.
congenital obliteration or hypoplasia of one or more components of the bile ducts, resulting in persistent jaundice and liver damage.
see imperforate buccopharyngeal membrane.
follicular atresia, atresia folliculi
premature degeneration and resorption of a graafian follicle of the ovary. It may be postovulatory or preovulatory atresia. It is a normal occurrence when several ova mature together. Abnormal atresia may be a cause of anestrus.
ileal atresia, atresia ilei
the congenital obstruction in calves may cause sufficient abdominal distention to result in dystocia.
inherited alimentary tract segmental atresia
occurs in cattle and horses. A variety of segments are involved, including ileum, colon, rectum and anus.
jejunal atresia, atresia jejuni
resembles ileal atresia clinically.
lacrimal puncta atresia
atresia of the lacrimal puncta causing tearing from birth.
mesonephric duct atresia
causes stenosis or aplasia of epididymis or ductus deferens.
nasolacrimal duct atresia
atresia of the nasolacrimal duct causing tearing from birth.
paramesonephric duct atresia
causes uterus unicornis or duplex uterus or segmental aplasia of a uterine horn or tube.
rectal atresia, atresia recti
congenital absence of luminal development leading to abdominal distention after birth. There is obvious absence of feces and staining and inability to pass a sound.
salivary duct atresia
congenital atresia causes distention of the gland followed by atrophy.
common in English bulldogs; may be segmental or affect the entire length of the tube.
absence of the opening between the right atrium and right ventricle, circulation being made possible by an atrial septal defect.