skeleton

• Vertebrates


  Bony skeleton inside the body<|>Use skeleton to move
• Skeleton


  • Supports the body and helps to move
  • Protects delicate organs including brain, heart, and lungs
• Skull


  Surrounds the brain
• Backbone


  A strong vertical column made up of a stack of smaller bones called vertebrae
• Rib cage


  A bigger cage made of rib bones that supports and protects the heart and lungs
• Joints


  Where two bones meet<|>Make the skeleton flexible and can move<|>Ball-and-socket joints in hips let the legs move in every direction<|>Hinge joints in knees can bend the legs<|>Similar joints in arms let them swivel around or bend

  
• When a muscle contracts

  It shortens to pull a bone into a different position
• Muscles


  Bundles of fibers that can contract or shorten<|>Each end of muscle is joined to a different bone by tendon (Non-stretchy tissue)Muscles can only pull, can't push the bone back

  
• Antagonistic muscles


  Muscles that work against each other to move the bones of the skeleton
• Cartilage


  Tough, rubbery material that covers the ends of bones to protect them

  
• Synovial fluid


  Cushions and lubricates the joint so the bones move smoothly without grinding against each other
• Arthritis


  The joints become damaged or diseased, making them very painful to move<|>Common in older people as all the tissues of the joint suffer from wear and tear with time