What is the only artery in the human body that carries deoxygenated blood?

The only artery in the human body that carries deoxygenated blood is the pulmonary artery. It transports oxygen-poor blood from the heart’s right ventricle to the lungs, where carbon dioxide is released and oxygen is absorbed.

The main pulmonary artery, also called the pulmonary trunk, leaves the right ventricle and divides into left and right pulmonary arteries. These branches carry blood toward the corresponding lungs, eventually dividing into smaller vessels that surround the alveoli, the tiny air sacs where gas exchange occurs.

This fact often surprises people because arteries are commonly defined as vessels carrying oxygen-rich blood. The more precise definition is that arteries carry blood away from the heart, while veins carry blood toward it. That is why the pulmonary artery is an exception to the usual oxygen rule. The pulmonary veins then return oxygenated blood from the lungs to the heart’s left atrium.