B5- Structure, Function, Disorders of muscular system

• Two types of Muscle contraction

  • Isommetric - muscle length does not change
  • Eccentric - muscle lengthens
  • Concentric
• Structure of Striated muscle

  • It is made up of fibres 
  • They contain a lot of mitochondria 
  • They have a striped appearance  
  • They are multinucleated 
• Outline how antagonistic muscles make a skeleton move

  • They are in pairs causing movement when one contracts
• Effects of muscular dystrophy on the body

  • Dystrophin is a protein in the body that is not produced properly
  • Duchenne is the most common type
  • Duchenne is a sex linked genetic disorder where muscle fibres break down causing gradual weakening
  • Life expectancy is shortenned
  • There is no cure
  • Physiotherapy may work in some cases
• Synergist

  • Stabilises joints
  • to assist muscles to work
• Fixator

  • Stabilises the joint
  • while the movement is peformed
• Role of skeletal system - Protection

  • Skull - prevents damage to the brain
  • Ribcage - prevents damage to lungs