A type of circulatory system in which blood circulates twice via the heart. The pulmonary circulation is separated from the systemic circulation in this form of circulation. The heart is divided into two halves in this circulation: the right side pumps deoxygenated blood into the pulmonary portion, while the left side pumps oxygenated blood into the systemic circulation. This is a common occurrence in both mammals and birds. In contrast, animals with only one circulatory system, such as fish, have two-chambered heard. The majority of mammals including humans have a double circulatory system, i.e. we have two loops in our body where the blood circulates. Double circulation is the movement of blood in the whole body and it involves the flow of-
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Oxygenated blood: Oxygen-rich
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Deoxygenated blood: Little to no oxygen, and a lot of carbon dioxide
What is a Circulatory System?
The circulatory system is made up of the heart and blood arteries. The circulatory system’s function is to transport oxygen, nutrients, and hormones throughout the body’s muscles, tissues, and organs. It is responsible for the transport of oxygen and nutrients to all cells, as well as the removal of carbon dioxide and waste products, the preservation of optimum pH, and the movement of the immune system’s components, proteins, and cells. The heart, blood vessels, blood, lymph, and lymph vessels are all part of the circulatory system. It is important to note that the circulatory system is often conceived as the vascular network that links the heart, which is the principal cardiac organ. Although the vascular network immediately related to the heart is technically only blood and blood vessels, the phrases circulatory and cardiovascular are sometimes used interchangeably.
Why is Blood Circulation in the Human Heart called Double Circulation?
It is important for human bodies as it ensures our tissues and muscles receive blood full of oxygen instead of the impure mixture of oxygenated and deoxygenated blood. The organ powering the double circulatory system is the heart that pumps blood through four chambers that include two atria and two ventricles. The four valves present in the heart keep blood moving in one direction and help in preventing the backflow of blood into the heart. The two valves are found in the heart itself and the other two valves are found in the major arteries in the heart. The major arteries of the heart are Aorta and Pulmonary Artery. All of these parts can be understood if we see the diagram of the heart with all labels.
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As we can see above in the picture, humans have four chambers in their hearts (whereas some organisms have two or three-chambered hearts such as in reptiles and fish). The human heart can be separated into two halves, separated by a muscle tissue called the septum; each half having an atrium that sits on the top of one ventricle.
It is referred to as a double circulatory system because here, the blood passes through the heart twice per circuit. The left pump sends the fresh oxygenated blood around the body and on the other hand, the right pump sends deoxygenated blood to the lungs where it becomes oxygenated and flows back to the heart. It is important for the separation of oxygenated and deoxygenated blood in human beings as it makes the circulatory system more efficient and also helps in maintaining the constant temperature of the body. Below are the four chambers of the heart playing an important role in the double circulation in human beings.
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Left Atrium: Receives oxygenated blood from lungs which contain oxygen.
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Right Atrium: It receives deoxygenated blood that contains CO2 as the byproduct of metabolism.
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Left Ventricle: It also receives oxygenated blood coming from the left atrium via a bi-cuspid valve.
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Right Ventricle: It receives deoxygenated blood consisting of CO2 from the right atrium via the tricuspid valve.
Below are the Blood Vessels Responsible for Carrying Out Double Circulation:
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Pulmonary Artery: It takes deoxygenated blood to the lungs.
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Aorta: It carries oxygenated blood to the body tissues.
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Pulmonary Vein: It carries oxygenated blood
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Vena Cava: It takes deoxygenated blood
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Two Types of Circulation: Double Circulation in Human
There are two types of circulation that work in the human circulatory system, namely the pulmonary and systemic circulatory systems. The pulmonary and systemic circulation are defined below.
Pulmonary Circulation
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Lungs are involved in this type of circulation.
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In this pathway, deoxygenated blood is transferred to the lungs via the pulmonary artery, and that deoxygenated blood comes from the right atrium to the right ventricle and the pulmonary artery.
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Now, carbon dioxide is removed and oxygen enters as a result of which blood carries oxygenated blood.
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This oxygenated blood is carried by Pulmonary Vein to the Left Atrium. Further, this blood goes to the Left Ventricle.
Systemic Circulation
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All systemic organs and tissues are involved in this type of circulation.
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Oxygenated blood will go to the tissues and organs via Aorta when it then becomes deoxygenated as a result of by-products (CO2) of metabolic and respiration processes.
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This deoxygenated blood is carried by Vena Cava to the right atrium and then further into the r
ight ventricle. -
And the cycle follows, the deoxygenated blood from the right ventricle goes to the lungs via the pulmonary artery. The CO2 is exhaled out from the lungs at that spot. If anyone asks to define double circulation, you can easily talk about pulmonary and systemic circulation and describe how blood enters twice to the heart and escapes twice out of the heart in the whole process. Therefore, it is known as double circulation.
What is the Advantage of Double Circulation?
Talking about the significance of double circulation, one can understand from the following points how efficient circulation is important for our bodies.
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It helps in maintaining higher blood pressure.
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It allows a greater flow of blood to the tissues.
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It helps in creating more pressure to pump blood around the whole body tissues and organs.
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A separation of oxygenated and deoxygenated blood is possible that leads to taking in oxygen-rich blood and removal of carbon dioxide from the blood through the lungs.
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It helps in producing a large amount of energy to maintain life processes.
In conclusion of the article, we have learned about double circulation, major organs involved in double circulation. We have also learned about the advantages of double circulation.