| aortic sac | In mammalian embryos, the endothelially lined dilation just distal to the truncus arteriosus; it is the primordial vascular channel from which the aortic arches arise and is homologous to the ventral aorta of gill-bearing vertebrates. (05 Mar 2000) |
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| aortic septal defect | A small congenital opening between the aorta and pulmonary artery about 1 cm above the semilunar valves, e.g., aorticopulmonary window. Synonym: aorticopulmonary window. (05 Mar 2000) |
| aortic sinus | The space between the superior aspect of each cusp of the aortic valve and the dilated portion of the wall of the ascending aorta, immediately above each cusp. Synonym: sinus aortae, Petit's sinus, Valsalva's sinus. Arlt's sinus, an inconstant depression on the lower portion of the internal surface of the lacrimal sac. Barber's pilonidal sinus, pilonidal sinus occurring in barbers, usually in the web between the fingers, due to the burying of exogenous hairs by the alternate loosening and tightening of tissues of the hand by the manipulation of scissors. (05 Mar 2000) |
| aortic sinus aneurysm | Abnormal dilation of one or more of the three aortic sinuses situated behind the three aortic valve cusps. (05 Mar 2000) |
| aortic spindle | A fusiform dilation of the aorta immediately beyond the isthmus. Synonym: His' spindle. (05 Mar 2000) |
| aortic stenosis | Progressive narrowing of the aortic valve resulting in the obstructed passage of blood from the left ventricle into the aorta. Causes for aortic stenosis include rheumatic fever, congenital and idiopathic sclerosis. Chronic stenosis can lead to left ventricular enlargement and congestive heart failure. (27 Sep 1997) |
| aortic sulcus | A broad deep groove on the medial aspect of the left lung above and behind the hilum receiving the arch of the aorta and the thoracic aorta. Synonym: sulcus aorticus. (05 Mar 2000) |
| aortic ultrasound | An ultrasound examination of the aorta to determine its size, shape and course. The diagnosis of abdominal aortic aneurysm can be made using this test. (27 Sep 1997) |
| aortic vestibule | The anterosuperior portion of the left ventricle of the heart immediately below the aortic orifice, having fibrous walls and affording room for the segments of the closed aortic valve. Synonym: Sibson's aortic vestibule, vestibulum aortae. (05 Mar 2000) |
| apical-aortic conduit | A valved conduit between the LV apex and aorta, used to treat severe otherwise unapproachable LV outflow tract obstruction. (05 Mar 2000) |
| calcific nodular aortic stenosis | Most common type of aortic stenosis, occurring usually in elderly men, in which the cusps contain calcified fibrous nodules on both surfaces; the causes include rheumatic fever, atherosclerosis, age-related degeneration, and congenitally bicuspid aortic valve. (05 Mar 2000) |
| valvular aortic stenosis | <radiology> Secondary to fusion of commisures between cusps types: bicuspid/unicuspid (95%): in 1-2% of population; M>F; commonly associated with coarctation, tricuspid (5%), dysplastic thickened aortic cusps in infants with crtical aortic stenosis: may stimulate neonatal sepsis, associated with L-R shunts (atrial septal defect, VSD), marked CMG (thickened wall of LV), pulmonary venous hypertension, congestive heart failure child/adult: LV configuration with normal heart size, postenotic dilatation, calcified valve (60% of patients greater than24 y.o.) see: aortic stenosis (12 Dec 1998) |
| para-aortic bodies | Small masses of chromaffin cells found near the sympathetic ganglia along the abdominal aorta. They serve as chemoreceptors responsive to oxygen, carbon dioxide, and hydrogen ion concentration, and help to control respiration. (12 Dec 1998) |
| cervical aortic knuckle | An anomalous aortic arch in which the aorta extends into the neck and forms an anteroposterior arch, which may be as high as the hyoid bone; the common carotid artery of one side is given off from the summit of the arch, and the common carotid of the other side arises from the more proximal part of the aorta; the pulsating arch may be mistaken for an aneurysm, but the radial pulses are equal. (05 Mar 2000) |
| right aortic arch | <radiology> Types: mirror image branching (95% most likely to be congenital ht disease), 90% tetralogy of Fallot (TOF) (25%) ** decreased PBF, 2.5% truncus (30-50%) ** increased PBF, 1.5% transposition (TGV) (5%), aberrant left subclavian artery (5% most likely to be congenital heart disease) (12 Dec 1998) |