Double circulation in human beings is a complex process that involves the circulation of blood through two separate pathways. The two pathways are the pulmonary circulation and the systemic circulation. The pulmonary circulation is responsible for carrying deoxygenated blood from the heart to the lungs, while the systemic circulation is responsible for carrying oxygenated blood from the heart to the rest of the body.

Necessity of Double Circulation:

Double circulation is necessary for the efficient functioning of the human body. It allows the body to maintain a constant supply of oxygen and nutrients to all the organs and tissues. The pulmonary circulation helps to oxygenate the blood, while the systemic circulation helps to distribute the oxygenated blood to the rest of the body. Without double circulation, the body would not be able to sustain the metabolic demands of the tissues and organs.

Process of Double Circulation:

The process of double circulation involves the following steps:

1. Deoxygenated blood enters the right atrium of the heart from the superior and inferior vena cava.
2. The right atrium contracts, pushing the blood into the right ventricle.
3. The right ventricle contracts, sending the deoxygenated blood to the lungs through the pulmonary artery.
4. In the lungs, the blood picks up oxygen and releases carbon dioxide.
5. The oxygenated blood returns to the heart through the pulmonary veins and enters the left atrium.
6. The left atrium contracts, pushing the blood into the left ventricle.
7. The left ventricle contracts, sending the oxygenated blood to the rest of the body through the aorta.
8. The oxygenated blood supplies the body with oxygen and nutrients and picks up waste products such as carbon dioxide.

Conclusion:

In conclusion, double circulation is an essential process that enables the human body to function efficiently. It ensures that oxygen and nutrients are delivered to all the organs and tissues while removing waste products such as carbon dioxide. The pulmonary and systemic circulation work together to maintain a constant supply of oxygenated blood to the body, facilitating its proper functioning.

Mammals have a double circulatory system. This means that during a single cycle, the blood goes twice in the heart. There are two loops in which blood is circulated. One loop is oxygenated and the other is de-oxygenated. This double circulatory system is important because it ensures provision of oxygenated blood to the muscle and not a mixture of oxygenated and de-oxygenated blood. Hence, this system ensures efficient supply of oxygenated blood to the muscles.