Anatomy Flashcards Chapter 9

Joint Classifications

• The joint between adjacent vertebrae, involving an intervertebral disc, is classified as amphiarthrosis.
• Joints that are classified as synarthrosis include the manubriosternal joint and cranial sutures.
• Biaxial diarthrosis joints include the metacarpophalangeal joint and hip joints.

Synovial Joints

• Synovial joints feature bones that articulate within a fluid-filled joint cavity.
• The synovial membrane secretes synovial fluid, which lubricates the joint and fills the joint cavity with a thick fluid.

Types of Joints

• Fibrous joints:

  • A syndesmosis connects the tibia and fibula.
  • Gomphosis joins teeth to the jaw.
  • The interosseous membrane of the forearm serves as a wide fibrous joint.

• Cartilaginous joints:

  • Symphysis occurs when bones are united by fibrocartilage, seen in adjacent vertebrae.
  • Synchondrosis is present at the first sternocostal joint and in the epiphyseal plate of growing long bones.

Joint Movements

• The ball and socket joint provides the greatest range of movement.
• Hinge joints allow for uniaxial movement.
• Condyloid joints, like the radiocarpal joint, enable various movements.
• Eversion moves the bottom of the foot away from the midline.
• Circumduction describes circular movement at a condyloid joint.
• Supination refers to the motion moving the hand from a palm backward to palm forward position.
• Abduction at the shoulder joint moves the upper limb laterally away from the body.

Additional Structures

• Bursa prevents friction by cushioning between skin and bone or muscle tendon and bone.
• A meniscus is a fibrocartilage pad that provides padding between bones.
• The articulation between the articular processes of adjacent vertebrae contributes to lateral flexion of the spine.

Flexibility and Adaptability

• Fontanelles in infants are wide areas of connective tissue between cranial bones, allowing skull flexibility during birth.