Respiration

• Aerobic respiration 


  A series of enzyme-controlled chemical reactions in the mitochondria of cells. Blood carries glucose and oxygen to the cells , they diffuse in and react releasing the stored energy from the glucose
• Anaerobic respiration


  A shorter series of enzyme- controlled reactions that partially breaks down glucose releasing only some of the energy stored. This reaction can occur in the absence of oxygen
• The amount of oxygen needed to remove the lactic acid is the oxygen debt and must be paid back when oxygen is readily available
• The respitory system

  The function of the respiratory system is to obtain sufficient oxygen for respiration and to remove the equivalent volume of waste gases, carbon dioxide and water
• Inspiration

  • Intercostal muscles contract, lifting ribs In and out
  • diaphragm contracts and flattens
  • chest cavity increases in volume and decreases in pressure below the pressure outside the body and so air is sucked into equalise the pressure
• Expiration

  • intercostal muscles, relax and ribs move down and in
  • diaphragm, relaxes and domes up
  • chest cavity decreases in volume and increases pressure air is forced out
• Gas exchange

  • The alveoli are adopted for gas exchange by good blood supply, large surface areas, thin walls, moist lining, as the red blood cells and plasma in the blood capillary flow around the alveolus, oxygen diffuses into capillary and carbon dioxide diffuses out