Final answer:
The pulmonary artery carries deoxygenated blood from the right ventricle to the lungs for oxygenation in the pulmonary capillaries. The oxygen-rich blood then returns to the heart through the pulmonary veins to complete the pulmonary circuit.
Step-by-step explanation:
The purpose of the blood vessel that carries deoxygenated blood from the right ventricle to the lungs is to transport the blood to the lungs for oxygenation. The specific blood vessel that performs this task is known as the pulmonary artery. Oxygenation of the blood occurs in the pulmonary capillaries which surround the alveoli of the lungs. Here, gas exchange takes place: carbon dioxide is expelled from the blood, and oxygen is absorbed.
After becoming rich in oxygen, the blood is then carried back to the left atrium of the heart through the pulmonary veins, the only veins in the post-natal body that carry highly oxygenated blood. This completes the pulmonary circuit and prepares the blood to be pumped throughout the body via the systemic circulation.