Functions of Blood

The main functions of blood are transport and fighting infection.

1. Transport

1. Heat in plasma helps maintain a body temperature of 37°C (homeostasis).
2. Oxygen is carried by red blood cells.
3. Plasma transports food, CO₂, hormones, salts, and urea.

2. Fight Infection

1. Platelets clot blood to prevent the entry of foreign cells.
2. Monocytes (white blood cells) surround and destroy foreign cells.
3. Lymphocytes (white blood cells) produce antibodies to destroy foreign cells.