Bones and muscles

• Ossification


  The development from cartilage to bone
• Growth goes upwards and downwards around the central marrow cavity
• Most bones are formed from cartilage
• Bones need minerals and vitamins to grow

  Calcium for strength

  Vitamin D build bone
• Key functions of the skeleton

  Movement(at joints)

  Protect(vital organs)

  Produce RBC andWBC(and bone marrow)

  Stores minerals(calcium)

  Muscular attachment(pulls bones to move , attached by tendons)
• Skeletal muscles


  Voluntary, full conscious control, attached to bones by tendons, cause movement
• Smooth muscles


  Involuntary, arteries, veins, stomach, no conscious control, divert blood away from the stomach to muscles during exercise
• Cardiac muscle


  Involuntary, automatic and rhythmic contractions, blood to lungs
• Slow twitch muscles


  Store oxygen in myoglobin, mitochondria process it. Lots of mitochondria and capillaries to transport work aerobically for long periods
• Slow twitch


  Type I contract slowly e.g. long distance
• Fast twitch


  Aerobic, fast contraction, light in colour as less mitochondria, no oxygen
• Fast twitch


  Type two A

  Aerobic, endurance increases resistance to fatigue 800m
• Fast twitch


  Type two X

  Anaerobic, generate a greater force, fatigue quickly 100 m
• Joints, ball and socket

  E.g. shoulder and hip

  Flexion, extension, abduction, adduction, rotation
• Joints hinge


  E.g. knee and elbow

  Flexion and extension
• Joints pivot


  Neck(Atlas and axis)

  Rotation
• Joints condyloid


  Wrist

  Flexion extension abduction adduction