Why is blood needed by all the parts of a body?

The functions of blood in our body are given below:
  1. Transportation of oxygen from the lungs to all parts of the body.
  2. It brings waste products like carbon dioxide from cells to the lungs.
  3. It fights against diseases and infections.
  4. It helps maintain body temperature.
  5. It carries waste products like urea from the liver to the kidneys for excretion in the form of urine.

The following list of steps in blood circulation:

1. The heart's left atrium receives oxygenated blood from the lungs via the pulmonary vein.

2. Through valve V1, oxygenated blood is pushed into the left ventricle when the left atrium contracts.

3. When the left ventricle contracts, oxygenated blood enters the aorta, the body's main artery. From there, it travels by tiny branches known as arterioles and capillaries to various sections of the body, excluding the lungs.

4. The bodily cells receive oxygen, food that has been digested, and dissolved substances from the oxygenated blood. Carbon dioxide, a waste product created during respiration, also enters the circulation at this time.

5. Deoxygenated blood carrying carbon dioxide leaves the body tissues and enters the vena cava, the principal vein that returns it to the right atrium of the heart.

6. Through valve V2, deoxygenated blood enters the right ventricle as the right atrium contracts.

7. Deoxygenated blood is returned to the lungs for oxygenation when the right ventricle contracts, entering through the pulmonary artery. The pulmonary vein transports the blood to the left atrium of the heart, where it is oxygenated once more before being circulated throughout the body. The entire procedure is continually repeated.


Simply Easy Learning

Updated on: 09-Jan-2023


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