IMMUNOLOGY

Detailed explanation-1: -The oxygenated blood is brought back to the heart by the pulmonary veins which enter the left atrium. From the left atrium blood flows into the left ventricle. The left ventricle pumps the blood to the aorta which will distribute the oxygenated blood to all parts of the body.

Detailed explanation-2: -The pulmonary veins bring oxygen-rich blood to the left atrium. The aorta carries oxygen-rich blood to the body from the left ventricle.

Detailed explanation-3: -The lung veins sometimes referred to as the pulmonary veins, are blood vessels that transfer freshly oxygenated blood from the lungs to the left atria of the heart.

Detailed explanation-4: -The blood returning to the heart from the lungs via the pulmonary vein has more oxygen per ml of blood. Pulmonary vein carries oxygenated blood from the lungs to the heart. Pulmonary Artery carries deoxygenated blood from the heart to lungs.