B4 - The structure, function, disorders of skeletal system

• Incidence of rickets may be changing

  • Rickets is caused by low calcium and vitamin D levels
  • Vitamin D is derived from the sunlight and diet
  • Calcium is derived from the diet
  • People with increased melanin in there skin make less vitamin D
  • Changes in diet, less dairy products containing calcium
  • Changes in leisure time, people spending less time outside
• Two functions of skeletal system

  • Support - by giving a rigid structure
  • Blood Cell production - in the marrow
• Compare fibrous joints and cartilaginous joints

  • Both joints connect bones
  • Fibrous joints joined by fibrous tissue
  • Cartilaginous joints joined by ligaments
  • Fibrous joints limited movement
  • Cartilaginous joints more movement
• Functions of synovial fluid in a joint

  • Lubrication - to prevent the joint overheating
  • Reduces friction - protect the joint
• Explain the problems that a fracture of the femur may cause

  • Inability to move due to the loss of stability
  • Pain due to damaged nerves
  • Infections due to exposed bone fragments
  • Deformity due to large muscle contracting and pulling the broken bone out of place
• Two kinds of joint, other than synovial


  • Cartilaginious
  • Fibrous
• Describe the Ligament in the skeletal system

  • Connective tissue
  • joins bone to bone
• Describe the Cartilage in the skeletal system

  • Flexible tissue
  • Reduces friction
• Describe the structure of the synovial joint

  • Where two bones join
  • Contains synovial fluid
  • Lined by synovial membrane
  • Fluid acts as lubricant
• Four types of bone

  • Long bones
  • Short bones
  • Flat bones
  • Irregular bones
• Role of skeletal system in blood cell production

  • Bone marrow
  • is the white cell blood production
• Explain the disorder of oestoathritis

  • Tear
  • Causing bones to grind
  • leading to inflammation in the joint
  • which causes irritation
• Function of skeletal system

  • Support
  • Protection
• What minerals does the skeletal system store?

  Calcium
• Explain the disorder oesteoporosis

  • Oesteoporosis weakens bones, making them fragile are more likely to break
  • It develops slowly and is only diagnosed after a sudden fall causing a bone to break
  • Injuries include, broken wrist, hip, spinal bones
  • Oesteoporosis is not usually painful until a bone is broken, which leads to long term pain
  • Older people develop the 'bent forward' posture when the spine is broken, making it difficult to support the weight of the body
  • It can be treated with bone strenghtening medicines
• Types of joint movement

  • Flexion - bending a joint
  • Extension - strengthening a joint
  • Abduction - movement away from the midline of the body
  • Adduction - movement towards the midline of the body
  • Circumduction – this is where the limb moves in a circle
• Two functions of synovial fluid in a joint

  • Reduces friction, to reduce pain
  • Provides additional protection, after an injury
• Describe how oesteoarthritis affects mobility

  • Pain - is the main affect for lack of mobilty
  • Causes swelling in the affected joint
  • Hips and knees are commonly affected
  • Thin cartilage - leading to rough surfaces in joint
  • Tissues around the joint stretch leading to reduced stability
  • Bony spurs irritate the joint and restrict movement