Movement in human

• Ligament: a short band of tough, flexible fibrous connective tissue which connects two bones or cartilages or holds together a joint. It avoids dislocation of bone during movement
• Tendon: a flexible but inelastic cord of strong fibrous collagen tissue attaching a muscle to a bone. It transmits the pulling force of contracting muscle to bone.
• Ball-and-socket joints are found in the shoulder, hip. All planes movement
• Hinge joint are found in elbow and knee. One plane movement
• Features of human skeleton that contributes to the unique upright posture of humans:

  • Vertebrae are large, forming a strong vertebral column supporting the body
  • Great pelvic girdle for supporting the upper part of the body
  • Thick femur for supporting the body
• Synovial fluid

  • lubricant
  • nourish the cartilage cells
• Synovial membrane secretes synovial fluid to reduce friction and supply oxygen and nutrients to the cartilage
• Compare the degree of movement allowed by ball and socket joint and knee joint

  Ball and socket joint allows movement of the bones in many planes while hinge joint allows movement of the bones in one plane only.
• Bone is a living tissue, which can carry out respiration, grow and repair itself
• Compare the elasticity of ligaments and tendons. Explain how elasticity is related to their functions.

  • Ligaments are elastic so as to allow a certain degree of flexibility in the movement of bones at the joint
  • Tendons are inelastic. This ensures that most of the force of muscle contraction can be transferred to the bones to bring about movement
• • With a decrease in the secretion of synovial fluid, there is more friction between the cartilage of the bones at the knee joint.
  • continuous rubbing leads to wearing of the cartilage. As a result, it would result in pain when the elderly walk.