PDHPE

• Functions of bones


  • Support for the body, giving it shape, form and posture
  • Protection of vital organs and soft tissue
  • Assistance in body movement: Provide the attachment for muscles and serve as levers
  • Produces blood cells (red and white) in the marrow cavities
  • Stores essential minerals such as calcium and phosphorus

  
• Types of bone


  • Long: longer than they are wide, function as levers
  • Short: have a short axis and found in small spaces, serve to transfer forces
  • Flat: have a broad surface and serve as places of attachment for muscles and to protect vital organs
  • Irregular: Primarily consist of cancellous bone, with a thin outer layer of compact bone
  • Sesamoid: usually short and irregular bones, imbedded in a tendon where it passes over a joint which protects the tendon
• Types of joints


  • Fibrous: Immovable joint where no movement is possible
  • Cartilaginous: Slightly moveable that permits limited movement
  • Synovial: Freely moveable that allows maximum movement
• Synovial joints


  • Ligaments: Fibrous bands that connect the articulating bones, maintain stability by restricting excessive movement
  • Tendons: Tough, elastic cords of tissue that attach muscle to bone
  • Synovial Fluid: Acts as a lubricant, keeping joints well oiled and moving surfaces apart, forms a fluid cushion between two joint surfaces
• Types of synovial joints

  • Plane: allows limited gliding movements
  • Hinge: allows movements along one axis for flexion or extension
  • Pivot: allows rotational movements and some bending
  • Ellipsoid/Condyloid: allows movement in two planes, allowing flexion, extension, adduction, abduction, and circumduction
  • Saddle: allows same movements as the condyloid but with no axial rotation
  • Ball-and-socket: allows movement through three planes and is the most mobile
• Components of a synovial joint

  • Articular cartilage: allows for smooth pain free movement
  • Synovial membrane and joint cavity: holds in the synovial fluid, providing the lubricant for the joint to move smoothly and pain free
  • Joint ligaments: hold the 2 bones involved in the joint together and help to restrict movement
• Anatomical reference: directional terms

  • Superior: towards the head
  • Inferior: towards the feet
  • Anterior: towards the front
  • Posterior: towards the back
  • Medial: towards the midline of the body
  • Lateral: towards the side of the body
  • Proximal: towards the body's mass
  • Distal: away from the body's mass