Joints Powerpoint

• Joint

  A point of contact between: two or more bones, cartilage and bone, teeth and bone

  
• Arthrology


  The scientific study of joints
• Structural classification of joints

  • Fibrous
  • Cartilaginous
  • Synovial

  
• Functional classification of joints

  • Synarthroses (immovable)
  • Amphiarthroses (partially movable)
  • Diarthroses (freely movable)

  
• Fibrous joints

  • Lack a synovial cavity
  • Articulating bones are held together with dense irregular fibrous connective tissue
  • Permit little or no movement

  
• Types of fibrous joints

  • Sutures
  • Syndesmoses
  • Interosseous membranes
• Suture


  A fibrous joint composed of a thin layer of dense fibrous connective tissue that unites skull bones

  
• Synostosis


  A suture joint that has ossified
• Syndesmosis


  A fibrous joint in which there is more fibrous connective tissue than in a suture
• Gomphosis (dentoalveolar)


  A fibrous joint in which a cone-shaped peg fits into a socket, e.g. the root of a tooth in its socket
• Cartilaginous joints


  • Lack a synovial cavity
  • Articulating bones are held together with cartilage connective tissue (fibrocartilage or hyaline cartilage)
  • Permit little or no movement

  
• Types of cartilaginous joints


  • Synchondroses
  • Symphyses

  
• Synchondrosis


  A cartilaginous joint in which the connecting material is hyaline cartilage, e.g. epiphysial growth plate

  
• Symphysis


  A cartilaginous joint in which the connecting material is a disc of fibrocartilage, e.g. intervertebral discs and pubic symphysis

  
• Synovial joints

  • Have a synovial cavity
  • Articulating bones are covered with articular cartilage
  • Held together by ligaments
  • Contain synovial fluid
  • Have a nerve and blood supply
  • Permit a large range of motion
  • Surrounded by an articular capsule

  
• Synovial fluid

  Secreted by the synovial membrane, lubricates and reduces friction in the joint and supplies nutrients to and removes metabolic wastes from the joint
• When disease or injury leads to a buildup of synovial fluid, the fluid may be aspirated and medications may be injected into the cavity
• Torn cartilage, occurring frequently in the knees of athletes, is damage to the articular discs that lie between the ends of some bones. Removal, to prevent erosion and arthritis, is usually accomplished by arthroscopy

  
• Autologous Chondrocyte Implantation


  A technique for cartilage replacement where chondrocytes are removed from the patient, grown in culture, and then placed in the damaged joint
• Sprain


  The forcible wrenching or twisting of a joint that stretches or tears its ligaments but does not dislocate the bone

  
• Strain


  A stretched or partially torn muscle
• Bursae


  Sac-like structures filled with synovial fluid that cushion movement of one body part over another
• Tendon sheaths


  Tube-like bursae that wrap around tendons subject to a great deal of friction
• Gliding movements


  Occur when relatively flat bone surfaces move back and forth and from side to side with respect to one another, with no significant alteration of the angle between the bones

  
• Angular movements


  Involve an increase or decrease in the angle between articulating bones

  
• Flexion


  Results in a decrease in the angle between articulating bones

  
• Extension


  Results in an increase in the angle between articulating bones

  
• Lateral flexion


  Involves the movement of the trunk sideways to the right or left at the waist, in the frontal plane
• Hyperextension


  A continuation of extension beyond the anatomical position, usually prevented by ligaments and bone alignment
• Abduction


  Movement of a bone away from the midline
• Adduction


  Movement of a bone toward the midline

  
• Rotation


  A bone revolving around its own longitudinal axis, permitted by pivot and ball-and-socket joints

  
• Medial rotation


  The anterior surface of a limb bone is turned toward the midline

  
• Lateral rotation


  The anterior surface of a limb bone is turned away from the midline

  
• Circumduction


  Movement of the distal end of a part of the body in a circle, resulting from a continuous sequence of flexion, abduction, extension, and adduction

  
• Elevation


  An upward movement of a part of the body
• Depression


  A downward movement of a part of the body
• Protraction


  A movement of a part of the body anteriorly
• Rotation


  A bone revolves around its own longitudinal axis

  
• Pivot and ball-and-socket joints


  • Permit rotation