Question

Oxygenated blood is carried by
A) Pulmonary vein
B) Pulmonary artery
C) Both A and B
D) None of the above

Answer 1

Hint: Veins bring blood to the heart. Pulmonary vein brings blood from lungs to the heart.

Complete answer:
We know that we carry a complex circulatory system of fluids like blood and lymph, in which the blood is the major fluid, pumped by the heart. The blood flows in closed pipelines called arteries and veins. It performs an exchange of gases, nutrients and waste material via capillaries at the level of tissues.
Generally, arteries have blood flowing with a pressure. Arteries are defined as blood vessels that carry the blood away from the heart. Now, blood is sent away from the heart to the different organs and tissues of the body through arteries. This blood is oxygenated, and supplies oxygen to the cells and tissues. So, we say that arteries carry oxygenated blood.

Similarly, the veins are the vessels that take the blood to the heart. This blood from the organs and tissues to the heart happens to be deoxygenated, in which tissues have given carbon dioxide. So, we say that veins carry deoxygenated blood.
However, this presumption of oxygenated blood in arteries and deoxygenated blood in veins changes when we look at the pulmonary circulation. It is the circulation that occurs between the heart and the lungs.
Now, if the blood has to go away from the heart to the lungs, the artery will perform it, as per definition of artery. But this blood is going to be deoxygenated as it has come all the way from the different parts of the body and has to go to the lungs for purification. So, the pulmonary artery carries the deoxygenated blood from the heart to the lungs. This is an exception to the arteries which generally carry oxygenated blood.

Similarly, if the blood has to come to the heart, it will be performed by the vein. So the pulmonary vein brings in the oxygenated or purified blood from the lungs to the heart. This is again an exception to the nature of the blood carried by the veins.

Therefore, the correct answer is option A.

Note: The circulation of blood between heart and lungs is called pulmonary circulation, whereas, the circulation of blood between heart and rest of the body is called the systemic circulation.