Transport

Abstract

You know what blood looks like. You probably know too that blood moves around the body. As it does so it acts as a transport system, picking up and delivering the following:

• oxygen from the lungs to the tissues

• carbon dioxide from the tissues to the lungs

• food from the gut to the tissues

• waste products, like urea, from the liver to the kidneys

• heat energy from the liver and muscles to cooler parts of the body

• chemical messengers (hormones) from the glands to other ‘target organs’.