Muscular system

• Skeletal muscles are attached to bones by tendons.
• Concentric contraction is the positive phase of contraction where muscle shortens
• Eccentric contraction is the negative phase of contraction where muscle returns to normal length
• Isometric contraction is where length of muscle does not change - leads to rapid fatigue
• Type 2x muscle fibres

  Anaerobic, Rapid high force contractions, Rapid fatigue
• DOMS


  Delayed onset of muscle soreness - occurs 24-48 hours after strenuous activity
• Storage of fat (A)

  Fat stores can be used as energy store via aerobic glycolysis
• Increase in glycogen store (A)

  More exercise = more glycogen store, can perform anaerobic activities for longer
• Increased blood supply (R)

  Vasodilation occurs to meet greater demand of oxygen to working muscles
• Increased Muscle Pliability (R)


  Warming of muscles allows them to stretch further, reduces chance of injury
• Increased muscle temperature (R)

  More chemical reactions occur during exercise - heat released as waste
• Increased myoglobin stores (A)

  Transports oxygen to mitochondria. More energy is then released available to muscle
• Increased no of mitochondria (R)


  Size of muscle fibres increase - More mitochondria. More aerobic respiration leads to longer aerobic performance
• Increased Tendon strength (A)


  Connective tissue at joint flexibility increases - Can withstand larger tensions
• Increased lactate tolerance (A)


  Anaerobic training improves lactate removal more efficient. Body can take in more oxygen
• Lactate Build up (R)

  waste product of anaerobic respiration, leads to rapid fatigue
• Micro-tears (R)


  Tiny tears occur due to stress on muscles, Body repairs using proteins which increase muscle size
• Type 1 muscle fibres

  Slow twitch, aerobic, low force, Rich blood supply
• Type 2a muscle fibres


  Fast twitch, resistant to fatigue, moderate blood and mitochondria supply
• 'all or nothing'


  Muscles must contract fully or not at all
• Age on muscular system

  Sarcopenia decrease muscle mass ---> decreased power and strength
• Cardiac muscle


  Can contract to push blood and does not fatigue
• Preventing cramp 


  keep hydrated ---> provides muscles with oxygen and minerals and stretching
• Anaerobic adaptations


  Hypertrophy, Tendon strength increase, lactate tolerance increase, Increased energy stores and use of.
• Cramp


  Sudden involuntary contraction of muscle fibres - caused by dehydration
• 'antagonistic pairs'


  Muscles work together to produce movement
• Smooth muscle

  Involuntary muscles located in walls of digestive system
• Agonist


  Responsible for movement taking place
• Antagonist


  Relaxes to allow movement - Acts as 'brake'
• Fixator


  Prevents unwanted movement - stabilises origin for effective contraction
• Skeletal muscle function


  Movement - pulls on bones
• Smooth muscle function


  Regulates digestion and blood flow
• Insertion


  End of muscle that moves
• Origin


  End of muscle which remains stationary
• Synergist


  Muscles work together to alter pull of agonist to advantageous position