Blood is an important medium in
- transport of oxygen and carbon dioxide
- In blood, oxygen combines with haemoglobin in the red blood cell to form oxyhaemoglobin.
- Oxygen is transported in the form of oxyhaemoglobin to the body cells which lack of oxygen.
- At the body cells, oxyhaemoglobin breaks down to release the oxygen to the body cells for cell respiration.
- Carbon dioxide is transported by the blood in ion hydrogen carbonate (ion bicarbonate) in the blood plasma carbaminohaemoglobin in the red blood cell.
- transport of water
- transport of digested food, minerals and vitamins
- transport of excretion
- transport of chemical substances such as hormones
- transport of heat