Question

The deoxygenated blood is carried out into which of the following organs?
A. Heart
B. Aorta
C. Liver
D. Lungs

Answer 1

Hint: The blood circulated throughout the body should be rich in oxygen. The deoxygenated blood is low in oxygen and high in carbon dioxide. So this blood needs to end up in a place to make it oxygenated. Closed type circulatory systems are found in humans.

Complete answer:
The deoxygenated blood is carried out into the lungs.
The human circulatory system is a closed one with two distinct paths. The tubes going out of the heart are generally called arteries and the tubes coming back to the heart are veins. The heart being in the middle, as a controller of the blood flow, the circulatory pathways are as follows:
> Systemic circulation – The main work of the heart is to pump blood with an adequate force so that it reaches all the tissues in the body. The blood going out of the heart in systemic circulation will be oxygenated. The blood coming back to the heart at the end of the cycle is deoxygenated. The living tissues all over the body need oxygen and metabolic nutrients, and it is dispersed through the bloodstream.
> Pulmonary circulation – This includes the pumping of deoxygenated blood from the heart to the lungs and oxygenated blood from the vicinity of lungs are carried out to the heart to take part in the systemic circulation. The exchange of gases between the lungs and arterioles carrying blood is the primary part of the respiratory system.
Systemic circulation also goes to the lungs to provide the oxygen necessary for lung tissues.

Note:
It can be tempting to assume heart as the right answer. Deoxygenated blood is indeed reaching the heart at some point. But the final destination of the deoxygenated blood is the lungs. This makes the heart just a pit-stop, rather than the final point.