structure of synovial joint

• structure of synovial joint

  A) articular capsule

  B) synovial membrane

  C) articular cartilage

  D) ligament

  E) articular discs

  F) tendon

  G) bursa

  H) synovial cavity

  I) synovial fluid

  J) bursa

  
• synovial cavity : space between articulating surfaces of bone
• synovial membrane : surrounds synovial cavity
• articular capsule : surrounds and encloses joint

  two layers : fibrous capsule and synovial membrane
• fibrous capsule : out layer of articular capsule

  a dense, fibrous connective tissue that is attached to the periosteum

  its flexibility permits the movement at the joint and strength resists dislocation
• synovial membrane : inner layer of articular capsule

  a loose connective tissue. its inner surface is well supplied with blood capillaries. it lines the entire joint cavity except where the articular cartilage is and articular disc if present
• synovial fluid : secreted by synovial membrane and fills the synovial cavity forming a thin film over surfaces within the capsule
• synovial fluid :

  • lubricates the joint
  • helps to keep articulating surface from making contact
  • provides nourishment for cells of articular cartilage
  • contains phagocytic cells that remove microorganisms and debris from wear and tear at joint
• synovial fluid is similar to egg white in appearance and consistency. there is only a small amount present but may increase especially in an injured or inflamed joint
• articular cartilage : covers articulating surface of bones
• articular cartilage provides a smooth surface for movement
• articular discs occurs in some synovial joints (e.g. meniscus in knee)
• bursae are little sacs of synovial fluid
• articular discs are fibrocartilage extending inwards from the articular capsule. it divides the synovial cavity into two so the synovial fluid can be directed to the area of greatest friction
• bursae are positioned to prevent friction between bones and a ligament or tendon, and a bones and the skin
• ligaments are a fibrous tissue that holds the bones together