Joints.pptx

• What is the definition of a joint?


  Joint = articulation
• What is the study of joints called?

  Arthrology
• What is the study of motion of the human body called?

  Kinesiology
• What are the three types of joints?

  • Fibrous
  • Cartilaginous
  • Synovial
• What is synostosis?


  Union or fusing of adjacent bones or developing bone
• Give an example of synostosis.


  Two halves of the frontal bone fuse at midline
• What are the characteristics of fibrous joints?


  • Held closely together by dense irregular connective tissue
  • Permit little to no movement
  • Two types: Sutures and syndesmosis
• What are sutures?


  A fibrous joint composed of a thin layer of dense irregular fibrous tissue
• Where do sutures occur?


  Only between bones of the skull
• How do sutures contribute to skull growth in infants and children?


  They are slightly moveable, allowing for growth
• What is syndesmosis?


  A fibrous joint with greater distance between bones compared to sutures
• What are the three types of syndesmosis?


  1. Interosseous ligament
  2. Interosseous membrane
  3. Gomphosis
• What is the function of cartilaginous joints?


  They allow for little or no movement
• What are the two types of cartilaginous joints?


  • Synchondrosis
  • Symphysis
• What is synchondrosis?


  A cartilaginous joint connected by a solid piece of cartilage
• Give an example of synchondrosis.


  Between the 1st rib and sternum
• What is symphysis?


  Ends of the bone are covered by hyaline cartilage with a flat disc of fibrous cartilage between
• Give an example of symphysis.


  Intervertebral discs
• What are the characteristics of synovial joints?


  • Articular cavity
  • Articular capsule
  • Articular cartilage
  • Varying degrees of movement
  • Decreased friction
  • Shock absorption
• What is the articular capsule?


  Connective tissue that encloses the articular cavity
• What are the two layers of the articular capsule?


  Fibrous layer and synovial membrane
• What is synovial fluid?


  A viscous fluid secreted by the synovial membrane
• What are the functions of synovial fluid?


  Lubricates joints, absorbs shock, supplies nutrients, and removes waste
• How does synovial fluid change with movement?


  It becomes less viscous with increased movement
• What are accessory ligaments in synovial joints?


  • Extracapsular ligaments (e.g., LCL, MCL)
  • Intracapsular ligaments (e.g., ACL, PCL)
• What are articular discs?


  Pads of fibrous cartilage between articular surfaces
• What is the function of articular discs?


  Absorb shock and improve fit between articulating surfaces
• What is the labrum?


  Fibrous ring-like cartilage in ball and socket joints
• What is the blood supply to joints?


  Joint capsule and ligaments have blood supply, while articular cartilage does not
• How do chondrocytes receive nutrients?


  Through synovial fluid derived from blood in the synovial membranes
• What is the nerve supply to joints?


  Nerves innervate the joint as well as nearby skeletal muscles
• What are bursae?


  • Sac-like structures that reduce friction
  • Act as cushions at some joints
  • Not part of the synovial joint
• What are tendon sheaths?


  Tube-like bursae that wrap around tendons experiencing friction
• What factors affect movement type and range of motion?

  • Structure and shape of articular bones
  • Strength and tension of joint ligaments
  • Arrangement and tension of muscles
  • Contact of soft tissues
  • Hormones (e.g., relaxin)
  • Disuse
• How does aging affect joints?

  Decreased synovial fluid production and thinner articular cartilage
• What is osteoarthritis?


  The most common type of arthritis characterized by degenerative joint disease
• What causes osteoarthritis?


  Aging, obesity, irritation of joints, muscle weakness, wear and abrasions, previous injuries
• Where is osteoarthritis most often found?


  In weight-bearing joints like hips and knees
• What is rheumatoid arthritis?


  An autoimmune disease where the immune system attacks joint tissues
• What happens if rheumatoid arthritis is untreated?


  Synovial membrane thickens, cartilage erodes, and bones may fuse