Vertebral Column

Cervical Vertebrae

  • The first seven bones are the smallest vertebrae that comprise the neck and support the head.
    • the first vertebra is the atlas, which appears as a bony ring and supports the head (up and down motions)
    • The second vertebra is the axis, which assists with the head's rotations (side-to-side shake).

Thoracic Vertebrae

  • Twelve vertebrae articulate with the ribs.
    • These bones are larger and stronger than the cervical vertebrae.

Lumbar Vertebrae

  • The five massive lumbar vertebrae support the weight of the body.

Sacrum and Coccyx

  • The sacrum is a shield-shaped portion of 5 fused vertebrae forming the posterior part of the pelvic girdle.
  • The coccyx is the lowermost portion of the vertebral column and is composed of four fused vertebrae.

Thoracic Cage

  • Includes the:
    • ribs
    • thoracic vertebrae
    • sternum
    • costal cartilages
    • Function: It supports the pectoral girdle and upper limbs, functions in breathing, and protects thoracic and upper abdominal organs.

Ribs

  • Normally, 12 pairs of ribs attach to the thoracic vertebrae
  • The first seven pairs of ribs are true (vertebrosternal) ribs that join the sternum directly by their costal cartilages.
  • The remaining five pairs are false ribs:
    • the first three pairs are vertebrochondral ribs
    • the last two are floating ribs (vertebral ribs).

Sternum

  • Three parts include:
    • Manubrium - the first rib attaches here
    • Body
    • Xiphoid process (most bottom part pointy)