The Skeleton and Movement Chapter 8

The 3 functions of the skeleton are: · Support · Protection · Movement

The bones of the arm are: Humerus Radius Ulna The bones of the leg are: Femur Tibia Fibula

The Spine The spine is made up of bones called vertebrae. Discs of cartilage found between the vertebrae act as shock absorbers and allow limited movement.

Joints Joints are formed where bones meet. Fused joints-These are immovable or fixed joints (e.g. bones of the skull). Moveable Joints contain synovial fluid and are called synovial joints.

Synovial joints. Synovial joints contain synovial fluid which cushions and lubricates the joint Cartilage-stops bones rubbing off each other.

Examples of moveable joints. Examples of moveable joints are: Ball and socket joint-allow movement in all directions (e.g. Hip and shoulder). Hinge Joint- allows movement in one direction only (e.g. Knee and Elbow).

Ligaments and Tendons Tendons join muscle to bone. E.g. Achilles tendon. Ligaments-join bone to bone.

Antagonistic muscles Antagonistic muscles work in opposite ways to each other (e.g. bicep and triceps muscles). When the biceps contracts, the arm is raised. To lower the arm, the triceps contracts and the biceps relax.