Its function is to transport a wide variety of substances and heat throughout the body.
It is divided into blood plasma (55%) and blood cells (45%).
Blood cells include red blood cells, white blood cells and platelets.
Red blood cells are nucleated, contain haemoglobin and are responsible for oxygen transport.
White blood cells are large and nucleated and function as part of our body's immune system.
Platelets are non-nucleated pieces of cytoplasm that are involved in wound repair.
Blood plasma is 90% water and carries substances and heat.
All people belong to one of the blood groups A, B, AB, or O (also referred to as blood types). The blood type must be known before a blood transfusion.
