Overview of Blood

Blood is composed of plasma and three types of cells: red blood cells, white blood cells, and platelets.

Blood contains plasma and blood cells, some of which have hemoglobin that makes blood red. The average blood volume in adult is five liters.

The main function of blood is to supply oxygen to tissues and remove carbon dioxide. Other functions include pH regulation and thermoregulation.

Plasma comprises about 55% of total blood volume. It contains proteins and clotting factors, transports nutrients, and removes waste.