aorta
What is the primary function of the aorta?
What are the major sections of the aorta?
What role does the aortic valve play in the circulatory system?
How does the aorta help maintain blood pressure?
What are some disorders that can affect the aorta?
aorta, the largest artery in the body, the primary route of blood transport in the systemic circulatory system. The aorta’s function is to carry oxygen-rich blood from the heart to organs and tissues. Blood enters the aorta from the left ventricle and blood flows into smaller arteries that then deliver oxygen and nutrients to tissues. An exception is the pulmonary circulation between the heart and the lungs, which bypasses the aorta.
- Size: In adults, roughly 30–40 cm (12–16 inches) in length and 2.5–3.5 cm (1–1.4 inches) in diameter.
- Major sections: Ascending aorta, aortic arch, thoracic aorta, and abdominal aorta.
- First branches: Right and left coronary arteries, which supply the heart muscle.
- Ends by dividing into: Right and left common iliac arteries, which supply blood to the pelvis and lower extremities.
- Key feature: Elastic walls move with each heartbeat, allowing for steady blood flow and blood pressure.
The aortic valve sits between the left ventricle and the aorta, opening as blood departs the ventricle and then closing immediately thereafter to prevent blood from draining back into the heart. The aorta is very flexible, having elastic tissues in its wall that allow for steady blood flow and blood pressure between contraction and relaxation of the heart muscle .
There are five regions that characterize the aorta structurally. The ascending aorta, which rises from the heart and splits into the right and left coronary arteries; these arteries deliver oxygenated blood directly to the heart muscle. The aorta then curves, producing the aortic arch; three major arteries branch from here to transport blood to the upper body region, mainly the head, neck, and chest. The aorta then continues down, a segment known as the descending aorta; this portion of the vessel, known as the thoracic aorta, passes through the chest and into the abdomen, giving rise to the abdominal aorta.
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As it descends, the aorta branches off into many smaller arteries that feed into major organs. The thoracic aorta, for instance, supplies arteries that deliver blood to the bronchi, diaphragm, esophagus, and nearby tissues. In the abdomen, arteries diverging from the aorta circulate blood to the adrenal glands, intestines, kidneys, liver, pancreas, spleen, stomach, and reproductive organs. Further down, the the right and left common iliac arteries branch off and continue to the pelvis and legs.
Disorders or injuries that affect the aorta are potentially life-threatening. Atherosclerosis, aortic aneurysm, and aortic dissection can severely undermine the aortic wall, reducing its elasticity and strength and thereby impacting blood flow. In some cases, these conditions can result in severe internal bleeding.