Keuhkoväylä

Keuhkoväylä, also known as the pulmonary artery, is a major artery that originates from the right ventricle of the heart and carries deoxygenated blood to the lungs. It is the only artery in the body that carries deoxygenated blood, with all other arteries carrying oxygenated blood. The pulmonary artery is part of the pulmonary circulation, which is responsible for oxygenating the blood.

Upon leaving the right ventricle, the pulmonary artery ascends for a short distance before bifurcating into the left and right pulmonary arteries. These branches then enter the lungs, where they further subdivide into smaller arteries and arterioles. Within the lungs, these vessels lead to capillaries that surround the alveoli, the tiny air sacs where gas exchange occurs. Here, carbon dioxide from the blood diffuses into the alveoli to be exhaled, and oxygen from inhaled air diffuses into the blood.

The oxygenated blood then returns to the left atrium of the heart via the pulmonary veins. The pulmonary artery is a relatively short and wide vessel compared to the aorta, the main artery that carries oxygenated blood from the left ventricle to the rest of the body. The pressure within the pulmonary artery is also significantly lower than in the systemic circulation. Conditions affecting the pulmonary artery can lead to serious health issues, including pulmonary hypertension and pulmonary embolism.