Question

Explain double circulation in Humans

Answer 1

Hint: The circulatory system is responsible for the transportation of nutrients and gases like oxygen for the body and carbon dioxide and the metabolic waste products away from the body. Based on the number of times blood flows through the heart in one cycle, circulation can be further classified.

Complete answer:
Based on the number of times blood circulation takes place through the heart in a cycle, a closed circulatory system is classified into Single circulation or Double circulation.’
Double circulation is a more efficient way of circulation, as it provides effective separate routes for oxygenated blood and deoxygenated blood. Hence, it is called “double circulation.” The majority of the mammals, including humans, utilize this system. This works as follows.
The human heart has four chambers: - Left Atrium - Right Atrium - Left Ventricle - Right Ventricle
Further, the heart is connected to the lungs by the pulmonary veins and artery. In double circulation, there are two distinguished pathways in which the blood flows. They are the systemic and pulmonary circulation:
Systemic circulation Systemic circulation carries oxygenated blood from the left ventricles to the tissues. The oxygen- rich blood is transferred to the aorta from where it is circulated to various parts of the body. Later, the venules and veins collect the deoxygenated blood that is rich in carbon dioxide from different parts of the body, which is then carried back to the right atrium of the heart through the vena cavae. After receiving the deoxygenated blood, the right atrium carries the blood to the right ventricle and then into the pulmonary circulation.
Pulmonary circulation In the pulmonary circulation, the blood circulation starts from the right atrium and ends at the left atrium. The pulmonary artery collects blood from the right ventricle and carries it to the lungs where it is oxygenated. After the purification, the oxygenated blood is pumped back to the heart through the pulmonary veins which enter the left atrium. The blood is then pumped to the left ventricle and from there the oxygenated blood is pumped to the aorta for systemic circulation.

Note:
Double circulation creates a strict separation of oxygenated and deoxygenated blood, unlike single circulation in which there is a mixing of oxygenated and deoxygenated blood which is inefficient. This is also one of the reasons why mammals can maintain their body temperature and are called warm-blooded animals.