Explain the relationship between the structure of a synovial joint and its ability to facilitate movement. (5 marks)
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- Synovial joints contain specialised structures that enable smooth movement between bones. The joint cavity filled with synovial fluid acts as a lubricant. This reduces friction between articulating surfaces, allowing bones to glide freely. During vigorous movement, additional fluid is pumped into the joint space. Consequently, cushioning increases when forces are greatest.
- Articular cartilage covers bone ends within the joint. This smooth surface works with synovial fluid to minimise friction further. As a result, bones can move repeatedly without wearing down. In weight-bearing joints, cartilage is thicker, which provides extra shock absorption.
- The joint capsule and ligaments offer controlled flexibility. These structures create a balance between stability and mobility. For instance, ball-and-socket joints have loose capsules, enabling multi-directional movement. In contrast, hinge joints have tight ligaments, restricting movement to one plane.
- Therefore, each structural component contributes to movement facilitation while maintaining joint integrity.
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Sample Answer
- Synovial joints contain specialised structures that enable smooth movement between bones. The joint cavity filled with synovial fluid acts as a lubricant. This reduces friction between articulating surfaces, allowing bones to glide freely. During vigorous movement, additional fluid is pumped into the joint space. Consequently, cushioning increases when forces are greatest.
- Articular cartilage covers bone ends within the joint. This smooth surface works with synovial fluid to minimise friction further. As a result, bones can move repeatedly without wearing down. In weight-bearing joints, cartilage is thicker, which provides extra shock absorption.
- The joint capsule and ligaments offer controlled flexibility. These structures create a balance between stability and mobility. For instance, ball-and-socket joints have loose capsules, enabling multi-directional movement. In contrast, hinge joints have tight ligaments, restricting movement to one plane.
- Therefore, each structural component contributes to movement facilitation while maintaining joint integrity.