BSC2085 Chapter 9 Lecture Powerpoint

Joints Overview

• Points where two bones meet

• Allow movement in the skeletal system

• Arthrology studies joint structure and function

Joint Classifications

• Named by bones involved (e.g., radioulnar joint)

• Four major types:

  • Bony joints (synostosis)

  • Fibrous joints (synarthrosis)

  • Cartilaginous joints (amphiarthrosis)

  • Synovial joints (diarthrosis)

Synovial Joints

• Most complex and mobile joints

• Separated by a joint cavity containing synovial fluid

• Composed of:

  • Articular cartilage

  • Joint cavity

  • Synovial fluid

  • Joint capsule (fibrous and synovial layers)

  • Accessory structures:

    • Tendons, ligaments, bursae, and tendon sheaths

Range of Motion (ROM)

• Degrees of movement possible at a joint

• Influenced by:

  • Articular surface structure

  • Ligament strength

  • Muscle and tendon actions

Types of Synovial Joints

• Six types: ball-and-socket, condylar, saddle, plane, hinge, pivot

Joint Movements

• Key terms:

  • Flexion: decreases angle

  • Extension: increases angle

  • Abduction: away from midline

  • Adduction: toward midline

  • Elevation/Depression: vertical movement

  • Protraction/Retration: horizontal movement

  • Circumduction: circular motion

  • Rotation: along longitudinal axis

  • Supination/Pronation: palm position changes

Specific Joints

• Shoulder Joint: Most mobile; vulnerable to dislocations

• Elbow Joint: Humeroulnar and humeroradial articulations

• Hip Joint: Supports weight; stable due to deeper sockets

• Knee Joint: Largest joint; protected by ligaments and menisci

• Ankle Joint: Limited mobility; prone to sprains

Joint Disorders

• Arthritis: Pain and inflammation; common types include

  • Osteoarthritis: wear-and-tear damage

  • Rheumatoid arthritis: autoimmune disorder, potential fusion of bones

• Arthroplasty: Joint replacement surgery using prosthesis