Question

Choose the correct answer from the alternatives given. WhichWhich of the following represents the pulmonary circulation as the blood flows from the right ventricle?
A. Pulmonary trunk $\to$ pulmonary veins $\to$ pulmonary capillaries $\to$ pulmonary arteries
B. Pulmonary arteries $\to$ pulmonary capillaries $\to$ pulmonary trunk $\to$ pulmonary veins
C. Pulmonary capillaries $\to$ pulmonary trunk $\to$ pulmonary arteries $\to$ pulmonary veins
D. Pulmonary trunk $\to$ pulmonary arteries $\to$ pulmonary capillaries $\to$ pulmonary veins

Answer 1

Hint: In human blood circulation is of a close type so it starts from the right ventricular region and ends here also through the pulmonary circulation. So we have to identify the path followed by human double circulation. Moreover, it generally follows from the right ventricle to left ventricle through the pulmonary trunk and arterioles.

Complete answer:
Physiology of blood circulation was first described by William Harvey in 1628. The proof on the circulation of blood was demonstrated on a dissected living snake and Harvey published his work in his book De Motu Cordis. According to him, there are two types of blood circulation in vertebrate:
(i) Single blood circulation: It is found in fishes in which blood passes once through the heart.

(ii) Double blood circulation: It is found in amphibians, reptiles, birds and mammals in which blood passes twice through the heart during one complete cycle. The complete double blood circulation is more prominent in birds and mammals due to complete division of ventricles.

The movement of blood in the organism follows a complicated course as the systemic or greater circulation and the pulmonary or lesser circulation. The systemic circulation Starts at the left ventricle of the heart, passes to the aorta, to the arteries originating from its whole body, and to all their branches. thence to the arterioles, capillaries and the veins of the whole body artery and all its branches, then along the pulmonary arterioles, capillaries and veins of the whole body and finally to the two venae cavae which enter the right auricle.

The pulmonary circulation begins from the right ventricle, continues along the pulmonary artery and pulmonary veins then Along the pulmonary veins which empty into the left auricle.

Hence, the correct answer is option (B).

Note: We have to remember the path of human double circulation from a tight ventricle to the left ventricle sequencely as blood flows through pulmonary circulation and systemic circulation then we can answer it. Mainly pulmonary circulation is the most important part of human double circulation because it carries oxygenated blood.