B9.2 - response to exercise

• Muscles require a lot of energy to carry out their functions
• Muscle tissue

  Made up of protein fiber that contract
• Energy production in muscles

  1. Energy is produced from respiration

  2. Muscles contain many mitochondria to carry out aerobic respiration

  3. Muscles store glucose as the carbohydrate glycogen

  4. Glycogen is rapidly converted to glucose during exercise

  5. Glucose is then used in aerobic respiration to produce energy for muscle contraction
• Muscle fibers

  • Usually occur in large blocks/groups
  • They contract to cause movement and then relax to allow other muscles to work
• When you exercise

  • Muscles contract harder and require more glucose and oxygen for respiration
  • Muscles also produce more carbon dioxide which needs to be removed
• Physical changes during exercise

  1. Heart rate increases

  2. Arteries supplying the muscles dilate (widen)

  3. This increases the flow of oxygenated blood to the muscles, providing more oxygen and glucose for cellular respiration

  4. It also increases the removal of carbon dioxide

  5. Breathing rate and breathing depth increase to bring more air into the lungs and facilitate the exchange of oxygen and carbon dioxide.
• Fuel for muscles during exercise

  1. Glycogen stored in muscle is converted back into glucose

  2. This provides cells with glucose for increased cellular respiration
• The increase in breathing and heart rate during exercise

  Is to supply the demand of the cells and remove the waste produced
• Cellular respiration increases to supply the muscle cells with the increased oxygen and energy needed to contract during exertion
• What happens when breathing rate and depth incease?

  • oxygen is brought to the body and picked up by red blood cells at a faster rate, it’s then carried to the muscles
  • CO2 is removed more quickly from the blood and is breathed out
• Why does breathing rate and heart rate increase?

  To supply the muscle with what they need to remove waste

  • cellular respiration increases to supply muscle cells with increased energy, the increase of breathing rate and heart rate supply’s the demand of the cells