Breathing

• Breathing


  When we breathe in and out we suck air into them then expel it again
• Gas exchange in the lungs


  1. Oxygen is absorbed from the lungs into the blood

  2. Carbon dioxide is removed from the blood and breathed out from the lungs
• Respiration


  The release of energy from glucose or other organic substances
• Types of respiration


  • Aerobic
  • Anaerobic
• Alveoli


  • Final branchings of the respiratory tree
  • Act as the primary gas exchange units of the lung
• Aerobic respiration


  • Takes place in the presence of oxygen
  • Glucose reacts with oxygen to release energy
  • Carbon dioxide and water are released as waste products
• Aerobic respiration


  1. Glucose molecules react with oxygen molecules to form carbon dioxide and water molecules

  2. Energy is released by the breaking of bonds in the glucose molecules
• During exercise


  • The body needs more energy and so the rate of respiration increases
  • Breathing rate increases to obtain extra oxygen and remove carbon dioxide
  • Heart beats faster to transport oxygen and carbon dioxide faster
• It is the build up of carbon dioxide that makes us breathe faster
• Anaerobic respiration


  • Occurs when oxygen is not available
  • Glucose is only partially broken down, and lactic acid is produced
  • Only a little bit of energy is obtained
• Anaerobic respiration


  • Releases less than half the energy of aerobic respiration
  • Produces lactic acid which causes muscle fatigue and pain