Vertebral column (Spine)

Overview

  • The vertebral column consists of 33 vertebrae.
    • 7 cervical
    • 12 thoracic
    • 5 lumbar
    • 5 sacral (fused)
    • 3–5 coccygeal (fused)
  • Functions of the vertebral column
    • Protects the spinal cord
    • Supports the weight of the head and trunk
    • Aids in respiration
      • Pump handle movement: superior and anterior movement of the sternum
      • Bucket handle movement: elevation of the lateral portion of the ribs
    • Supports the upright position for bipedalism

Anatomy

Vertebrae

Consist of a vertebral body and a vertebral arch, which together form the vertebral foramen

Intervertebral disc

Regions of the vertebral column

Atlanto-axial subluxation is associated with rheumatoid arthritis, Down syndrome, and osteogenesis imperfecta (among other conditions)!

Curvatures of the vertebral column

  • Primary curvatures (kyphosis, formed during fetal development)
    • Thoracic
    • Sacral
  • Secondary curvatures (lordosis, formed after birth)
    • Cervical (from lifting of the head)
    • Lumbar (from adopting the upright position and walking)

Ligaments

Anatomy Function
Anterior longitudinal ligament
  • Supports the annulus fibrosus anteriorly
  • Limits hyperextension of the vertebral column
Posterior longitudinal ligament
  • Limits hyperflexion of the vertebral column
Ligamenta flava
Nuchal ligament
  • Runs from the external occipital protuberance to C7
  • Attached to the posterior tubercles of the atlas and spinous processes of cervical vertebrae
  • Triangular shape
  • Limits hyperflexion of the vertebral column
Supraspinous ligament
  • Limits hyperflexion of the vertebral column
Interspinous ligaments
Intertransverse ligaments
  • Limit lateral hyperflexion of the vertebral column

Vessels

Arterial system

The vertebral column is supplied by branches of the aorta and vertebral, subclavian, and internal iliac arteries.

  • Cervical: Vertebral artery and subclavian branches
  • Thoracic: Segmental branches from the aorta
    • Divided into lateral and dorsal branches
  • Lumbar: Segmental branches from the aorta
    • Divided into lateral and dorsal branches
  • Sacral: Branches of the internal iliac artery
    • Iliolumbar, lateral, and sacral arteries
    • Middle sacral artery

Venous system

Formed by valveless venous plexuses

  • Vertebral vein
  • Internal vertebral venous plexus
    • Found within the epidural space (between the dura mater and the vertebral canal)
    • Connects with veins from the spinal cord, vertebral veins, basilar plexus, occipital and sigmoid dural sinuses
    • Communicates with pelvic, azygos, and caval veins via Batson venous plexus → thought to be the route of metastasis
    • Drains into intervertebral veins and basivertebral veins (within vertebral bodies)
  • External vertebral venous plexus
    • Anterior branches lie anterior to the vertebral column.
    • Posterior branches lie on vertebral arches.
    • Communicates with the internal vertebral venous plexus
    • Connects with the vertebral, posterior intercostal, lumbar, and lateral sacral veins

Embryology

The vertebral column is derived from the somites of the paraxial mesoderm; , beginning in the 4th week of embryonic development.

Clinical significance

last updated 04/01/2019
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