Describe the working of human blood circulatory system with the help of a suitable diagram which shows all the steps involved.

Working of human blood circulatory system:

The human circulatory system consists of three independent systems that work together: the heart (cardiovascular), lungs (pulmonary), and arteries, veins, coronary and portal vessels (systemic). These systems are responsible for the flow of blood, oxygen, nutrients, as well as hormones to and from cells.

The human heart is a muscular organ divided into four chambers. The upper two chambers are called right and left atrium and the lower two chambers are called the right and the left ventricles. It is located just behind and slightly left of the breastbone.

Steps involved in the blood circulation are given below:

1. The pulmonary vein brings the oxygenated blood from the lungs in the left atrium of the heart.

2. When the left atrium contracts, the oxygenated blood is pumped into the left ventricle through valve V1.

3. When the left ventricle contracts, the oxygenated blood enters the main artery called the aorta which transports the blood to different parts of the body except for lungs, through small branches called arterioles and capillaries.

4. The oxygenated blood gives oxygen, digested food and dissolved materials to the body cells. At the same time, carbon dioxide, which is produced as waste material during respiration, enters into the blood.

5. From the body tissues, the deoxygenated blood carrying carbon dioxide enters the main vein called vena cava which carries it back to the right atrium of the heart.

6. When the right atrium contracts, the deoxygenated blood enters into the right ventricle through valve V2

7. When the right ventricle contracts the deoxygenated blood enters back to the lungs through the pulmonary artery for oxygenation. The blood becomes oxygenated again and is sent to the left atrium of the heart by pulmonary vein for being circulated in the body. 

This whole process is repeated continuously.


Simply Easy Learning

Updated on: 24-Mar-2023


Kickstart Your Career

Get certified by completing the course

Get Started