Circulation refers to the movement of substances such as gases and nutrients within your blood vessels as well as cavities throughout your body. The circulatory systems can be closed (as in fish and mammals) or open (as in insects). In case of closed circulator systems, you may notice single circulatory systems with two-chambered heart. In some cases, you may notice double circulatory systems with a four-chambered heart. Humans and so many other organisms have a double circulator system, which means they have two separate circuits for blood in their bodies. Keep reading to find out more about double circulatory system in humans.

What Is Double Circulatory System?

Double circulatory system enables the process of double circulation by which the cardiovascular system of birds and mammals circulates blood throughout the body. In this system, the heart needs to pump the blood twice to work properly. Here is a bit more about the two circulations that structure the double circulatory system.

1. The Pulmonary Circulation

This refers to the circulation of blood from your heart to your lungs and then back to the heart again. The right ventricle pumps deoxygenated blood coming from the body to the heart through the pulmonary artery. The blood becomes oxygenated in the lungs and returns to the left atrium through the pulmonary veins.

2. The Systemic Circulation

This refers to the circulation of blood to the rest of your body (except the lungs) and then back again to your heart. The oxygenated blood from the left ventricle moves to all part of the body through the aorta, which is your body's main artery. It supplies blood to all the body's organs. It supplies blood to the heart through the coronary arteries.

Here is how the whole process works:

Heart → lungs → heart → body

Check out the following video to learn more about double circulatory system:

What Are the Advantages of Double Circulatory System?

Is there any advantage of double circulatory system? By comparing it with open circulatory system and single circulatory system, you will answer it by yourself.

Compared with Open Circulatory System

When compared with open circulatory system, a closed circulatory system works more efficiently. It is mainly because the blood can circulate only inside blood vessels, and it can travel greater distances due to a higher pressure. It even reaches the organs and peripheral tissues with ease. It also maintains a relatively higher circulatory speed that promotes better distribution of oxygen to tissues, including large tissues such as muscle tissues. That is the reason why animals with an open circulatory system have a slower metabolic rate and are generally slower.

Compared with Single Circulatory System

In the single circulatory system, blood only passes once through the heart. In double circulatory systems, it passes twice through the heart. For instance, the blood passes through the heart of fish once only. The heart receives oxygen-deprived blood and pumps it to the gills where the exchange of gases takes place and oxygenated blood moves throughout the body.

Double circulatory systems prevent the mixing of the oxygenated and deoxygenated blood. It is due to this particular reason that the blood travels through the rest of the body with a higher concentration of oxygen and at a higher pressure as well.