Which of the following statements are correct regarding the given figure?

(i) The parts labelled as Q and R carry blood having low oxygen concentration.
(ii) The parts labelled as P, Q and R carry blood having low oxygen concentration.
(iii) The blood flows out of the heart through blood vessel Q when ventricle contracts.
(iv) The blood is flowing out of the heart through blood vessel Q when atria contract.

Options

A. (ii) and (iv) only
B. (ii), (iii) and (iv) only
C. (i), (ii) and (iii) only
D. (i) and (iii) only

Answer

D

Explanation

In the given figure, .P. is aorta, .Q. is pulmonary artery and .R. is superior vena cava. .R. brings deoxygenated blood from all body parts towards the heart and Q carries this blood towards lungs for oxygenation. Thus, both .Q. and .R. carry blood having low oxygen concentration. .Q. arises from the right ventricle so the blood will move into this blood vessel only when the ventricle contracts to push the blood into it. At this time, the atrium relaxes. .P. carries oxygenated blood from the left ventricle to all body parts.