Study Notes on Joint Structures and Movements

Joint Capsule and Synovial Membrane

• Joint capsule is outer layer of connective tissue connected to periosteum of bone.
• Inner layer is the synovial membrane, which produces synovial fluid.

Synovial Fluid

• Synovial fluid fills spaces between bones, providing support to synovial joints (e.g., knee).

Joint Capsules

• Joint capsules are specifically found around synovial joints.
• Act as ligaments, holding synovial membrane.

Meniscus and Fibrocartilage

• Meniscus is a type of fibrocartilage lacking blood vessels; slow to repair.
• Damage leads to extended recovery or surgical intervention.

Types of Synovial Joints

• Ball and socket: Most freely moving (e.g., hip, shoulder).
• Hinge: Allows movement in one plane (e.g., elbow, knee).
• Pivot: Limited rotation (e.g., forearm).
• Saddle: Allows opposition (e.g., thumb).
• Gliding: Allows gliding movement (e.g., wrist).
• Condyloid: Oval-shaped surfaces allowing varied motion.

Joint Movements

• Types of movements include:
  • Flexion/Extension/Hyperextension
  • Abduction/Adduction
  • Rotation/Circumduction
  • Pronation/Supination
  • Eversion/Inversion
  • Elevation/Depression
  • Retraction/Protraction

Muscle Function

• Muscles can only pull across joints; opposing muscles facilitate movement in opposite directions.
• Origin: stationary end, Insertion: moves toward the origin during contraction.

Cartilage Types

• Hyaline cartilage is found on articular ends of bones, facilitating smooth joint movement.