Following are the main constituents of blood:

● Plasma- The liquid matrix of the blood.

● Red blood cells - Red blood cells play an important role in your health by carrying fresh oxygen throughout the body.

● White blood cells - White blood cells (WBCs)also called leukocytes or leucocytes, are the cells of the immune system. They are responsible for protecting the body against diseases.

● Platelets - Platelets are tiny blood cells that help your body form clots to stop bleeding.

If any blood vessel is damaged, it sends out signals that are picked up by platelets.