muscular system

• Muscular system

  • Made up of: muscle fibres + the cells within
  • Responsible for the utilisation of oxygen + production of ATP
  • Allows our muscles to contract and create movement
• Increased A-VO2 difference

  ⭐: the difference in oxygen content of the arterial blood and the venous blood

  RESTING: ↓ A-VO2 difference

  EXERCISING: ↑ A-VO2 difference

  *increase in A-VO2 difference shows that muscles are taking in more oxygen when exercising
• Increased blood flow to working muscles

  • Allows for a greater delivery of oxygen to meet oxygen demand to produce more ATP
  • Allows body to sustain the increased ATP demands that come with exercise
• Increased motor unit recruitment

  ⭐: motor unit = made up of neutron and the muscle fibre it stimulates (used to ‘talk’ to the muscles - controls muscular contractions)

  • To increase force production, the body:
  • Signals for more units to work
  • Signals to activate the unit more often
• Increased muscle temperature

  • Heat is a metabolic byproduct of the aerobic system
  • Increase heat produced -> increase muscle temperature
• Increased metabolic by-products

  ⭐: waste substances that are a byproduct of the chemical reactions used to produce ATP

  • See an increase in H+ ions via anaerobic glycolysis system and Pi (inorganic phosphate) via ATP-PC system
  • Happens during exercise that is heavily reliant on anaerobic pathways
• Decreased intramuscular energy substrates

  ⭐: intramuscular substrates = the fuels within our muscles that are used to produce ATP i.e. ATP, PC, glycogen + triglycerides
• Increased enzyme activity

  ⭐: enzyme = responsible for speeding up chemical reactions

  • Body increases use of enzymes to speed up the metabolism of fuels to allow for faster rate of ATP production
• acute responses

  • increased blood flow to working muscles
  • increased motor unit recruitment
  • increased blood flow to working muscles
  • decreased intramuscular energy substrates
  • increased enzyme activity
  • increased metabolic byproducts
  • increased A-VO2 difference