Lecture Notes: Classifications of Joints

Overview of Articulations

• Articulation: Connection point where two or more bones meet to form a joint.
• Functions: Provide skeleton with mobility and stability.
• Trade-off: Higher stability often means lower mobility and vice versa.
  • Stable Joints: Have tight, strong tissue; less mobile.
  • Mobile Joints: Have softer or less tissue; more mobile, less stable.

Classifications of Joints

Structural Classifications

• Fibrous Joints
  • Made of dense regular connective tissue.
  • Example: Cranial sutures (immovable).
• Cartilaginous Joints
  • Made of cartilage.
  • Can be either immovable or slightly movable.
• Synovial Joints
  • Made of synovial membrane (lubrication membrane).
  • Freely movable.

Functional Classifications

• Synarthrosis
  • Immovable joints.
  • Example: Cranial sutures.
• Amphiarthrosis
  • Slightly movable joints.
  • Example: Distal tibiofibular articulation.
• Diarthrosis
  • Freely movable joints.
  • All synovial joints fall under this category.
  • Examples: Shoulder joint, hip joint.

Relationship Between Structure and Function

• Fibrous Joints: Mostly synarthrotic (immovable).
• Cartilaginous Joints: Can be synarthrotic or amphiarthrotic (slightly movable).
• Synovial Joints: All diarthrotic (freely movable).

Conclusion

• The material composition of joints often determines their mobility and stability.