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(āôr`tə), primary artery of the circulatory systemcirculatory system,
group of organs that transport blood and the substances it carries to and from all parts of the body. The circulatory system can be considered as composed of two parts: the systemic circulation, which serves the body as a whole except for the lungs, and the
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 in mammals, delivering oxygenated blood to all other arteries except those of the lungs. The human aorta, c.1 in. (2.54 cm) in diameter, originates at the left ventricle of the heartheart,
muscular organ that pumps blood to all parts of the body. The rhythmic beating of the heart is a ceaseless activity, lasting from before birth to the end of life. Anatomy and Function

The human heart is a pear-shaped structure about the size of a fist.
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. After supplying the coronary arteries that nourish the heart itself, the aorta extends slightly toward the neck to feed branches serving the head and arms. It then arches down toward the waist, directing blood into the arterial system of the chest. Entering the abdomen through the aortic hiatus, an opening in the diaphragm, the aorta branches off to supply the stomach, kidneys, intestines, gonads, and other organs through extensive arterial networks. It finally divides into the two iliac arteries carrying blood to the legs. The elasticity of the aorta wall permits it to pulse in rhythm with the heartbeat, thus helping to propel blood through the body.



the main artery of the greater circulatory system, which supplies blood to all organs of the body.

The wall of the aorta consists of three membranes, that is, the interior (a layer of endothelial cells), intermediate (numerous rows of elastic fibers), and exterior (bundles of connective tissue fibers). Because of the elasticity of the aorta’s walls an uninterrupted flow of blood in the arteries is assured. In man, mammals, and birds, the aorta emerges from the left ventricle of the heart, forming an enlargement at its very beginning, called the aortic spindle, goes up (ascending aorta), turns back and to the left in man and mammals (arch of the aorta) and back and to the right in birds, and goes down (descending or dorsal aorta). In reptiles there are two aortic arches, that is, the right, or arterial, arch, emerging from the left ventricle of the heart; and the left, or venous, arch from the right ventricle. When they unite, they form a common aorta with mixed blood. In amphibians an arterial cone emerges from the only ventricle, and from it one pair (in ecaudates) or two pairs (in caudates) of aortic arches branch out, which form the dorsal aorta when they unite. In fishes and cyclostomes the ventricle passes into the abdominal aorta, which carries venous blood through the system of arterial arches into the gills (in fishes) and gill pouches (in cyclostomes). The blood which is oxygenated there is collected in the dorsal aorta. Of the invertebrates, mollusks and arthropods have aortas.


Ostroverkhov, G. E., D. N. Lubotskii, and Iu. M. Bomash. Kurs operativnoi khirurgii i topograficheskoi anatomii,2nd ed. Moscow, 1964.
Cole, W. H. Textbook of Surgery,8th ed. New York, 1963.


The main vessel of systemic arterial circulation arising from the heart in vertebrates.
(invertebrate zoology)
The large dorsal or anterior vessel in many invertebrates.


the main vessel in the arterial network, which conveys oxygen-rich blood from the heart to all parts of the body except the lungs
References in periodicals archive ?
One end of the aorta with endothelium was attached to a force-displacement transducer in a Magnus chamber to record its isometric contraction.
Perillaldehyde caused vasodilatation in the endothelium-free aorta
Aorta strips were contracted by an application of calcium ionophore A23187 to Krebs solution, and perillaldehyde was subsequently added at cumulatively increasing doses of 0.
The present study clearly shows that perillaldehyde acts as a vasodilator in the isolated rat aorta.
There was no difference in vasodilative effect between the aorta with or without endothelium, suggesting a direct effect of perillaldehyde on vascular smooth muscle cells.
The vasodilative effect of perillaldehyde was scarcely present in the aorta contracted by the calcium ionophore A23187.
Inhibitory effect of Cinnamomi Cortex and cinnamaldehyde on oxygen-derived free radical-induced vasoconstraction in isolated aorta of spontaneously hypertensive rats.
The acrolein--dG adduct levels in the cockerel abdominal aortas were not measured after the 8 weeks of acrolein exposure because all the tissues were taken for morphometric analysis.
The experiments described here focused on the connection between inhalation exposure to environmentally relevant levels of acrolein, acrolein--DNA adduct formation in the aorta, and aortic plaque development.
Fourth, the increased acrolein--dG adduct levels in cockerel aorta DNA in vivo confirm and extend Earlier in vitro findings that avian artery wall cells are more sensitive to treatment with acrolein, or its precursor allylamine, than are rat artery cells (17).
Aneurysms might result from any of a variety of mutations in the collagen III gene or in other genes that code for proteins used in constructing the aorta wall, Prockop suggests.
Darling predicts that some patients might opt for elective surgery to patch the damaged aorta wall rather than wait for the balloon to burst.