Question

List four functions of the human heart. Why is double circulation needed in our body?

Answer 1

Hint: The human heart is a muscular organ that plays a central role in the circulatory system of our body. It is located- in between the lungs, behind the breastbone, or the sternum, and slightly to the left. It is four-chambered. It supplies oxygenated blood after the purification of deoxygenated blood.

Complete answer:
The human heart is a muscular organ derived from the embryonic disc. It is about the size of our fist and pumps blood involuntarily throughout its life span. It is covered by a -thick heart wall made up of three layers. The endocardium is the inner layer, and the pericardium is the outer layer. The myocardium lies between them.
The heart is separated into two different parts by a muscular layer- right and left. These parts are further subdivided to form four chambers. The upper chambers of the heart are called atrium or auricles, and the lower chambers of the heart are called ventricles. The auricles receive deoxygenated blood from the body, and the ventricles release oxygenated blood.

The major functions of the heart are-
1)Receiving deoxygenated blood from the body tissues and supplying oxygenated blood.
2)Pumps, or supplies blood to various organs and tissues.
3)It also helps to maintain and regulate the blood pressure level in our body. It does this by providing an adequate supply of blood in our body.
4)It removes the waste products and carbon dioxide from the blood. These waste products are further eliminated or excreted from the body. The heart purifies the blood and makes it oxygen-rich.

The heart performs the purification of blood because it is necessary to remove the wastes and carbon dioxide and make it suitable for transportation and oxygen-rich. For the purification of the blood, it has to flow through the heart twice. Therefore, there is a double circulation network in the heart. It prevents the mixing of deoxygenated and oxygenated blood from each other. It makes sure that properly oxygenated blood is supplied to- different tissues and organs in our body. It also helps to maintain the high blood pressure level in our body as it pumps the blood with more pressure.
The double circulation pathway takes place in two steps: pulmonary circulation and systemic circulation.

The pulmonary circulation requires the involvement of the lungs. Systemic circulation involves different organs and tissues. The deoxygenated blood is carried by the Vena cava- to the right atrium. The blood passes through the tricuspid valve to reach the right ventricle. It passes through the pulmonary valve and reaches the pulmonary artery. The artery carries this deoxygenated blood to the lungs. Removal of carbon dioxide and the addition of oxygen occurs in this process, and the blood becomes oxygenated. The oxygenated blood is carried from the lungs to the heart again by a pulmonary vein. The blood enters the left atrium and passes through the bicuspid valve to reach the left ventricle. From the left ventricle, the blood passes the aortic valve and flows through the aorta to reach various organs and tissues in our body. The blood released from the organs and tissues gets deoxygenated due to the respiratory processes. This deoxygenated blood is further brought back to the heart through the Vena cava.
This systemic flow of blood through double circulation helps the proper supply of oxygen-rich blood in our body. It also generates a large amount of energy.

Note: Double circulation pathway is a characteristic feature of all birds and mammals. It is possible due to the presence of a well defined four-chambered heart. The deoxygenated blood is dark red and a high amount of carbon dioxide and waste particles. The oxygenated blood is bright red and has a high amount of oxygen and a low amount of carbon dioxide.