Synovial Joints Lecture by Dr. Mike

Overview of Joint Types

• Fibrous Joints: Limited movement
• Cartilaginous Joints: Some movement
• Synovial Joints: Freely movable (Focus of the lecture)

General Structure of Synovial Joints

1. Articulating Cartilage
   • Cartilage lining the surface of bones
   • Type: Hyaline cartilage
   • Function: Reduces friction
2. Synovial Capsule (Articular Capsule)
   • Fibrous Layer: Dense connective tissue, holds joint tight
   • Synovial Membrane: Inside layer, simple squamous epithelia
3. Synovial Fluid
   • Functions:
     • Creates frictionless environment
     • Provides cushioning
     • Delivers nutrients and removes waste

Types of Synovial Joints

• Mnemonic: Prince Harry Pulled Charles's Saddle Bag
  • P: Planar
  • H: Hinge
  • P: Pivot
  • C: Condylar
  • S: Saddle
  • B: Ball and Socket

Classification by Movement

• Uniaxial: Moves in one plane
• Biaxial: Moves in two planes
• Multiaxial: Moves in more than two planes

Detailed Types of Synovial Joints

Uniaxial Joints

1. Planar Joint
   • Example: Carpals (e.g., triquetrum and hamate)
   • Movement: One plane, gliding movement
   • Structure: Flat surfaces
2. Hinge Joint
   • Example: Elbow joint (humerus, radius, ulna)
   • Movement: One plane, like a door hinge
3. Pivot Joint
   • Example: First and second cervical vertebrae (C1 and C2)
   • Movement: One plane, rotational movement
   • Structure: Rounded bone within a circular bone or ligament

Biaxial Joints

1. Condylar Joint
   • Example: Metacarpal and proximal phalanx (2 to 5)
   • Movement: Two planes
   • Structure: Similar to ball and socket but less deep
2. Saddle Joint
   • Example: Trapezium and first metacarpal
   • Movement: Two planes
   • Structure: Saddle-shaped surfaces

Multiaxial Joint

1. Ball and Socket Joint
   • Example: Hip joint (femur and hip)
   • Movement: Multiple planes
   • Structure: Deep joint allowing for extensive movement

Summary

• Six types of synovial joints: Planar, Hinge, Pivot, Condylar, Saddle, Ball and Socket
• Classified by their movement capabilities: Uniaxial, Biaxial, Multiaxial
• Important examples and structural features highlighted for each type