Question

Mammals are said to have double circulation, it means
A. Blood vessels are paired
B. These are two types of blood vessels attached to every organ
C. There are two organs
D. The blood structures twice through the heart

Answer 1

Hint: The circulatory system is responsible for the transport of nutrients and gases like oxygen, for the body and metabolic waste products away from the body. The heart and the lungs play a significant role in the circulating and decontamination of blood throughout the body. The heart is the chief organ for blood circulation as it gives an effective way of circulation.

Complete answer: In the body, two circulatory organs are not present. It is not necessary that any organ has two types of blood vessels attached to it.
Double circulation includes mammals. Whereas the left ventricle channels blood into the aorta, the blood pumped by the right ventricle pierces the pulmonary artery.
Usually, there are two sets of paired blood vessels on either side that are formed from the tiny venules, contributing to discharge into the left atrium away from the pulmonary capillaries.
The deoxygenated blood pumped through the pulmonary artery is redirected through the lungs from where the oxygenated blood flows through the left atrium through the pulmonary veins. The pulmonary circulation contains this pathway. A complex of arteries, arterioles, and capillaries transport the oxygenated blood exiting the aorta to the tissues, from which the de-oxygenated blood is collected by a chain of venules, veins, and vena cava and discharged into the right atrium. This is known as systemic circulation.
So, the correct answer is “Option D”.

Note: Double circulation bears a strict division of both oxygenated and deoxygenated blood. Systemic circulation takes in oxygenated blood from the left ventricles to the tissue capillaries. As a result, this circulation ensures that the body always has a keen supply of oxygen, and also, it develops body effectiveness. This is why mammals can preserve their body temp