Anoka-Ramsey Community College 4

Joint Anatomy and Function

• Joint Movement

  • Radius and Ulna Interaction:

    • The radius rotates over the ulna, enabling movement.

    • This rotation necessitates movement along the length of these two bones.

    • Incorporates longer fibers to accommodate movement.

  • Joint Cavity:

    • Bones are separated by a cavity that allows space for movement.

    • Must connect one bone to another to maintain joint integrity.

Protecting Surrounding Tissues

• Tissue Damage Prevention:

  • Movement can potentially damage surrounding tissues if not properly protected.

  • Structural features must support movement while safeguarding adjacent tissues.

Features of Joints

• Nerve Supply:

  • Joints have nerves that send signals and provide feedback about joint position and movement.

• Blood Supply:

  • Joints must have some form of blood supply.

  • Blood vessels are not inside the joint cavity to avoid disruption during movement.

Joint Movement Examples

• Wrist Movements:

  • The wrist joint allows multiple movements including flexion and extension, as well as lateral movement (side to side).

• Elevation and Depression:

  • Movement can include actions like elevation (lifting) and depression (lowering).

  • For example, mandible movement parallel to shoulder blade elevation exemplifies these joint actions.