Final Answer:
The blood from the areas caudal to the heart is brought back to the heart by the Vena cava. Thus the correct option is (4).
Step-by-step explanation:
The vena cava, comprising the superior and inferior vena cava, serves as the primary conduit for deoxygenated blood returning from the systemic circulation to the right atrium of the heart. The superior vena cava collects blood from the upper part of the body, including the head and arms, while the inferior vena cava gathers blood from the lower part of the body, such as the legs and abdominal region. As the heart contracts during diastole, these major veins facilitate the return of blood to the right atrium, initiating the pulmonary circulation.Thus the correct option is (4).
In a circulatory cycle, deoxygenated blood is pumped from the right atrium into the right ventricle, and then it is propelled into the pulmonary artery for oxygenation in the lungs. The oxygenated blood, now in the pulmonary veins, is transported to the left atrium. Upon contraction of the left ventricle, it is pumped into the aorta, initiating the systemic circulation.
As the blood travels through the body, delivering oxygen and nutrients, it gradually becomes deoxygenated. The vena cava then plays a crucial role by collecting this deoxygenated blood, completing the circuit by returning it to the heart, and enabling a continuous flow of blood through the cardiovascular system.