Question

What is meant by double circulation? What is its significance?

Answer 1

Hint: The cardiovascular system and the vascular system are the other names of the circulatory system in the human body. We know that this system permits the blood in our body to circulate and transport nutrients such as amino acids and electrolytes, gases like oxygen, carbon-di-oxide including many hormones, and red blood cells from and to the cells in the human body. This is done to provide nutrition and help the human body to fight against diseases. It also stabilizes the temperature and pH in the body, and maintains homeostasis.

Complete answer:
One can define that the process of double circulation includes the travel of blood through the heart twice during one complete circulation.
The double circulation includes two types of circulation, they are:
- Systemic circulation
- Pulmonary circulation

From the left ventricle of the human heart towards the aorta a movement exists which is called the systemic circulation. Further, a network of arteries, arterioles, and capillaries to the tissues carries the blood. The venules, veins, and vena cava will collect the deoxygenated blood. It will get emptied into the left auricle.

From the right ventricle towards the pulmonary artery, a movement of deoxygenated blood exists which is called the pulmonary circulation. Further, the blood goes to the lungs for oxygenation. The oxygenated blood is carried by the pulmonary veins into the left atrium from the lungs.

We can say that the blood has to pass alternately through the lungs and the tissues in the process of double circulation.

Note: The organisms which include the amphibians, reptiles, birds, and mammals have double circulation. On the other hand, it is more prominent in birds and mammals since they have a heart that is completely divided into four chambers. These four chambers include the right atrium, the right ventricle, the left atrium, and the left ventricle. The amphibians and reptiles have a weak double circulation.