overriding aorta


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aorta

 [a-or´tah] (pl. aor´tae, aortas) (L.)
the great artery arising from the left ventricle, being the main trunk from which the systemic arterial system proceeds. It has four divisions: the ascending aorta, the aortic arch, the thoracic aorta, and the abdominal aorta. See Appendix of Arteries and see circulatory system.
 Aorta, arising from the left ventricle, ascending, arching, then descending through the thorax to the abdomen, where it divides into the common iliac arteries. From Dorland's, 2000.
overriding aorta a congenital anomaly occurring in tetralogy of Fallot, in which the aorta is displaced to the right so that it appears to arise from both ventricles and straddles the ventricular septal defect.

o·ver·rid·ing a·or·ta

a congenitally malpositioned aorta the origin of which straddles the ventricular septum and so receives ejected blood from the right ventricle as well as from the left; it is found especially in tetralogy of Fallot.

aorta

pl. aortae, aortas [L.] the great artery arising from the left ventricle, being the main trunk from which the systemic arterial system proceeds. See Table 9. See also aortic.

abdominal aorta
the part of the descending aorta within the abdomen.
ascending aorta
the first part of the aorta which passes dorsally and cranially.
descending aorta
the aorta after it turns caudally at the aortic arch.
overriding aorta
see overriding aorta.
supravalvular aorta
the portion of aorta immediately above the aortic valve.
terminal aorta
the segment of the aorta immediately before it divides into the iliac arteries.
thoracic aorta
the part of the descending aorta within the thorax.

overriding

1. the position of fracture fragments in which they overlap one another.
2. anomalous positioning of major blood vessels, e.g. aorta or pulmonary arteries.
3. a law or order which overrides, or takes precedence over, a law or order of a court or legislature of lower standing.

overriding aorta
a congenital anomaly occurring in tetralogy of Fallot, in which the aorta is displaced to the right so that it appears to arise from both ventricles and straddles the ventricular septal defect.
overriding pulmonary artery
a congenital cardiac defect in which the pulmonary artery straddles a defective interventricular septum and the aorta originates in the right ventricle.