Question

Which pulmonary blood vessel carries oxygen-rich blood?

Answer 1

Oxygenation of blood occurs in the lungs and the oxygenated blood is drained into the left atrium of the heart by a specific blood vessel. The walls of this blood vessel are thinner compared to the blood vessel that carries deoxygenated blood from the heart to the lungs.

Complete Answer:
The oxygenated blood from the lungs is carried to the heart by the pulmonary vein.
In almost all mammals double circulation is seen, it has the following components:
-Systemic Circulation: The systemic circulation includes the circulation which helps in the distribution of oxygenated blood from the left ventricle of the heart to all the different body parts and draining of deoxygenated blood from all the body parts into the right atrium of the heart. The oxygenated blood passes from the left ventricle to the aorta, from the aorta to the arteries. The arteries further branch into arterioles, capillaries, venules and these again unite to form veins of the whole body. Finally, two vena cava drain into the right atrium of the heart. Systemic circulation is also known as greater circulation or peripheral circulation as it supplies blood to a majority of body tissues.
-Pulmonary Circulation: It consists of the pathway of deoxygenated blood from the right ventricle to the lungs via the pulmonary artery and oxygenated blood from the lungs to the left atrium via the pulmonary vein.
-The systemic and pulmonary circulation together constitute the double circulation.

Note:
The lungs help in the exchange of gases and release carbon dioxide from the bloodstream into the atmosphere and from the atmosphere they inhale oxygen which mixes with blood and is carried to the heart.