vertebral column

Study Notes for Vertebral Column

Step Four: Study Focus

  • Vertebral Column:
    • Essential to understand its structure, interrelations, and functionalities.
    • Includes cervical, thoracic, lumbar vertebrae, sacrum, and coccyx.

Vertebrae Types and Features

  • Cervical Vertebrae (7):

    - Distinguished by distinctive features such as transverse foramen.

    • Key vertebrae:
    • Atlas - C1: supports the skull.
    • Axis - C2: allows for rotation.
    • Odontoid Process (Dens): a crucial feature of the axis for head rotation.

  • Thoracic Vertebrae (12):

    • Features articulate with ribs.

  • Lumbar Vertebrae (5):

    • Positioned in the lower back and characterized by larger bodies.

Essential Bone Markings (Exercise 10)

  • Common Features on All Vertebrae:
    • Body: main weight-bearing structure.
    • Spinous Process: posterior projection for muscle attachment.
    • Vertebral Foramen: large opening for the spinal cord.
    • Superior Articular Facets: articulate with adjacent vertebrae.
    • Transverse Process: lateral projections for muscle attachment.
    • Intervertebral Foramen: passage for spinal nerves; requires two vertebrae to visualize.
    • Inferior Articular Facets: articulate with lower vertebrae.
    • Lamina: connects processes and forms the vertebral arch.
    • Intervertebral Discs: fibrocartilaginous cushions between vertebrae.
    • Pedicle: cylindrical part that connects the vertebral body to processes.

Sacrum

  • Comprises five fused vertebrae.

  • Sacral Features:

    • Sacral Foramina: openings for the passage of sacral spinal nerves.
    • Sacral Promontory: prominent feature articulating with L5's inferior surface.
    • Sacroiliac Joint: connects the sacrum to the ilium.

  • Coccyx: tailbone, composed of fused vertebrae.

Significance of Bone Markings

  • Transverse Foramen:
    • Passageway for vertebral arteries that supply blood to the brain.
  • Vertebral Foramen:
    • Critical passage for the spinal cord through the vertebral column.
  • Intervertebral Foramen:
    • Key passage for spinal nerves entering and exiting from spinal cord.
  • Odontoid Process (Dens):
    • Extension from the axis allowing for rotation of the head, enabling the 'no' movement.
  • Sacral Foramina:
    • Routes for sacral spinal nerves to exit.
  • Sacral Promontory:
    • Clinically significant for gender identification and obstetrics, due to articulation with L5.

Articulations Involving Sacrum

  • The sacrum articulates with:
    • Fifth Lumbar Vertebra (L5)
    • Coccyx
    • Ilium (part of the pelvic girdle)

Surgical Considerations

  • Laminectomy:
    • Purpose: Surgical procedure performed to decompress the spinal cord or nerves.
    • Typically involves removing a section of the lamina to relieve pressure.

Joints of the Axial Skeleton

  • Atlanto-occipital Joint:
    • Articulation between the superior articular facets of the atlas and the occipital bone of the skull.
    • Facilitates the nodding motion of the head.
  • Atlantoaxial Joint:
    • Formed by the odontoid process of the axis articulating with the atlas.
    • Responsible for the left/right rotation of the skull, enhancing head mobility.