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aortic arch n
1) one of the arterial branches in vertebrate embryos that exist in a series of pairs with one on each side of the embryo, that connect the ventral arterial system lying anterior to the heart to the dorsal arterial system above the alimentary tract, and that persist in adult fishes but are reduced or much modified in the adult of higher forms
2) ARCH OF THE AORTA
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that part of the aorta that extends from the ascending aorta, upward over the heart and then backward and down as far as the fourth thoracic vertebra. stretch receptor in its outer wall monitor blood pressure and form part of the system maintaining this at a constant level.
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1. arcus aortae. 2. any of a group of paired vessels arching from the ventral to the dorsal aorta through the branchial arches of fishes and the pharyngeal arches of amniote embryos. In mammalian development, arches 1 and 2 disappear; arch 3 joins the common to the internal carotid; the left arch 4 remains as the arch of the definitive aorta while the right arch 4 joins the aorta to the subclavian artery; arch 5 is absent or disappears; and the ventral halves of arch 6 form the pulmonary arteries while the connections to the dorsal aorta are lost, although the left half, or ductus arteriosus, serves as an arterial shunt until birth.Medical dictionary. 2011.