Red Blood Cells (OCR GCSE Physical Education (PE)): Revision Note

The role of red blood cells

• The main function of blood is to transport nutrients and oxygen to the cells of the body

• Blood consists of four main components:

  • red blood cells – these transport oxygen around the body

  • white blood cells - serve to fight infection

  • platelets - these clot to prevent blood loss during injury

  • plasma - contain nutrients essential for energy production

Red blood cells

• Red blood cells are disc-shaped cells with no nucleus

• Their flattened shape gives a relatively large surface area which increases the speed of diffusion (gaseous exchange) as they pass through the lungs 

• Red blood cells are very important for sport and physical activity because they contain haemoglobin  

  • After diffusing into the blood oxygen binds to haemoglobin within red blood cells to form oxyhaemoglobin: oxygen + haemoglobin→ oxyhaemoglobin 

    • Haemoglobin can also bind to carbon dioxide, aiding the transport of waste carbon dioxide (CO2) from the muscles back to the lungs where it can be exhaled 

• Aerobic training increases the volume of red blood cells in the body

  • This means there is more haemoglobin and as a result the efficiency of oxygen transport for aerobic energy production increase