The aorta (pronounced /eɪˈɔrtə/; from Greek ἀορτή - aortē, from ἀείρω - aeirō "I lift, raise")^[1] is the largest artery in the body, originating from the left ventricle of the heart and bringing oxygenated blood to all parts of the body in the systemic circulation.^[2] The aorta extends down to the abdomen, where it branches off into two smaller arteries.

scheme of the aorta

[edit] The course of the aorta

The aorta is usually divided into five segments/sections:^[3][4]

• Ascending aorta—the section between the heart and the arch of aorta
• Arch of aorta—the peak part that looks somewhat like an inverted "U"
• Descending aorta—the section from the arch of aorta to the point where it divides into the common iliac arteries
  • Thoracic aorta—the half of the descending aorta above the diaphragm
  • Abdominal aorta—the half of the descending aorta below the diaphragm

[edit] In other animals

All amniotes have a broadly similar arrangement to that of humans, albeit with a number of individual variations. In fish, however, there are two separate vessels referred to as aortas. The ventral aorta carries de-oxygenated blood from the heart to the gills; part of this vessel forms the ascending aorta in tetrapods (the remainder forms the pulmonary artery). A second, dorsal aorta carries oxygenated blood from the gills to the rest of the body, and is homologous with the descending aorta of tetrapods. The two aortas are connected by a number of vessels, one passing through each of the gills. The fourth such vessel survives in amniotes as the arch of the aorta, while the others disappear or are incorporated elsewhere in the arterial tree. Amphibians also retain the fifth connecting vessel, so that the aorta has two parallel arches.^[5]

[edit] Features

The aorta is an elastic artery, and as such is quite distensible. When the left ventricle contracts to force blood into the aorta, the aorta expands. This stretching gives the potential energy that will help maintain blood pressure during diastole, as during this time the aorta contracts passively.

Anterior (frontal) view of the opened human heart. White arrows indicate normal blood flow.

[edit] Diseases/pathology

• Aneurysm of sinus of Valsalva
• Aortic aneurysm - myotic, bacterial (e.g. syphilis), senile, genetic, associated with valvular heart disease
  • Dissecting aortic aneurysm
• Aortic coarctation - pre-ductal, post-ductal
• Atherosclerosis
• Marfan syndrome
• Ehlers-Danlos syndrome
• Aortic stenosis
• Trauma, such as traumatic aortic rupture, most often thoracic and distal to the left subclavian artery^[6] and frequently quickly fatal^[7]

[edit] References

[edit] External links

Look up aorta in Wiktionary, the free dictionary.

• Gray's s153 - Descending aorta
• Gray's s154 - Abdominal aorta