Sample Answer

• Tendons are tough, inelastic cords of fibrous connective tissue that connect muscles to bones. This fibrous composition enables them to withstand tremendous pulling forces during muscle contractions. Because of their inelastic nature, tendons ensure direct force transmission without energy loss.
• When muscles contract, they pull on tendons, which then pull on bones across joints. This creates movement at the joint. For example, the Achilles tendon transfers force from calf muscles to the heel bone, enabling powerful push-off during running.
• Tendons cross joints strategically, which allows them to guide movement direction. Working together with ligaments, they maintain joint stability during motion. As a result, joints can move precisely without excessive deviation.
• The positioning of tendons around joints determines movement patterns. In the fingers, multiple tendons create complex movements for fine motor control. Therefore, tendon structure and placement enable both powerful movements and delicate precision tasks.

Sample Answer

• Immovable (fibrous) joints consist of bones held firmly together by dense fibrous connective tissue. This rigid connection prevents any movement between bones, ensuring complete stability.
• In skull sutures, the interlocking edges of adjacent cranial bones create a jigsaw-like pattern. These interlocking surfaces increase contact area and strengthen the connection, forming a protective shell.
• The dense fibrous tissue fills all gaps between bones. Such complete fusion provides maximum strength to withstand external forces and protect vital organs like the brain.
• Unlike synovial joints, immovable joints lack joint cavities and synovial fluid. The absence of these structures reflects their specialised function of providing stability rather than movement.

Sample Answer

Overview Statement

• The skeletal system comprises bones, ligaments, cartilage and synovial joints that interact to create a balance between movement capability and structural stability.
• These components work together through precise structural arrangements.

Component Relationship 1

• Bones and ligaments form an interdependent relationship at joints.
• Bones provide rigid levers for muscle attachment, while ligaments connect these bones with controlled flexibility.
• This interaction enables joints to move within safe ranges.
• At the knee, the femur and tibia are linked by cruciate ligaments that prevent excessive rotation yet allow flexion for walking.
• The pattern shows that ligament length and strength directly influence the joint’s movement range.
• Consequently, this bone-ligament relationship determines both stability and mobility parameters.

Component Relationship 2

• Synovial joint structures work together to reduce friction during movement.
• Articular cartilage combines with synovial fluid to create a low-friction environment.
• This interaction leads to efficient energy use during repetitive movements.
• During running, increased synovial fluid production responds to joint loading, providing enhanced cushioning when needed most.
• This reveals how the system adapts to movement demands dynamically.

Implications and Synthesis

• These relationships mean that skeletal system efficiency depends on all components functioning optimally.
• Damaged cartilage affects fluid distribution, which impacts movement smoothness.
• Therefore, the integrated nature requires comprehensive care – maintaining ligament flexibility, cartilage health, and adequate synovial fluid.
• The significance is that movement efficiency and joint longevity rely on this complex interplay.

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.

Sample Answer

Lubrication:

• Synovial fluid acts as a lubricant, keeping joints well-oiled and moving surfaces apart.
• This reduces friction between articular cartilages during movement.

Cushioning:

• Forms a fluid cushion between joint surfaces, particularly important during vigorous movement when additional fluid is pumped into the joint space.

Nutrition and waste removal:

• Provides nutrients to articular cartilage which lacks blood supply.
• Simultaneously removes waste products, maintaining healthy cartilage and overall joint function.

Sample Answer

Structure:

• Articular cartilage is a smooth, shiny layer of tissue that covers the ends of bones in synovial joints.
• Thicker in weight-bearing joints like the knee, it lacks blood vessels and receives nourishment from synovial fluid.

Function:

• Articular cartilage acts as a cushion between contacting bone surfaces (joint facets), allowing bones to move freely over each other with minimal friction.
• It absorbs shock and distributes forces across the joint, protecting bones from direct contact and wear during activities.

\(D\)

\(C\)

\(A\)

\(B\)