How does blood circulation occur in humans?

Blood circulation in humans occurs through a closed circulatory system in which the heart pumps blood through a network of blood vessels.

The process begins when oxygen-poor blood from different parts of the body enters the right side of the heart through veins. This blood is then pumped to the lungs, where carbon dioxide is removed and oxygen is absorbed.

The oxygen-rich blood returns to the left side of the heart and is pumped through arteries to all body parts. In the capillaries, oxygen and nutrients are exchanged with body cells, and waste products are collected.

The deoxygenated blood then returns to the heart through veins, and the cycle repeats continuously.

This continuous circulation ensures proper transport of oxygen, nutrients, hormones, and waste materials throughout the body.