The aorta is the largest artery in the human body.
It begins at the left ventricle of the heart and carries oxygen-rich blood into the body's systemic circulation. From the heart, it rises as the ascending aorta, curves through the aortic arch, and continues downward as the descending aorta. Its branches supply the head, arms, chest, abdomen, and legs.
The aorta is sometimes confused with the pulmonary artery because both are major vessels leaving the heart. However, the pulmonary artery carries oxygen-poor blood to the lungs, while the aorta distributes oxygen-rich blood to the rest of the body. The aorta's thick, elastic wall helps it withstand the high pressure produced by ventricular contraction.
Aortic aneurysms and aortic dissection are serious conditions involving this vessel. The aortic valve, located between the left ventricle and aorta, helps stop blood from flowing backward into the heart.