XBONZ

Vertebral Column: How to Tell Cervical, Thoracic and Lumbar Vertebrae Apart

By XBONZ ·

A single vertebra is one of the commonest spotters, and one of the easiest to get right once you know what to look for. There are 33 vertebrae: 7 cervical, 12 thoracic, 5 lumbar, 5 fused sacral and 4 fused coccygeal. The 24 movable ones share the same plan, and the regions differ in three things.

Three questions that give the region

  1. Is there a hole in the transverse process? A foramen transversarium means cervical. Nothing else has it.
  2. Are there smooth facets on the sides of the body or on the transverse processes? Costal facets for the ribs mean thoracic.
  3. Is the body large and kidney-shaped, with no holes and no facets? Lumbar.

Typical cervical vertebra (C3 to C6)

  • Small, wide body, longer from side to side than front to back; the upper surface is concave from side to side with raised lateral lips.
  • Foramen transversarium in each transverse process, for the vertebral artery (from C6 upwards), vertebral veins and a sympathetic plexus.
  • Large, triangular vertebral foramen.
  • Short spine, bifid at the tip.
  • Articular facets flat and set obliquely, the superior ones facing backwards and upwards.

Typical thoracic vertebra (T2 to T8)

  • Heart-shaped body, with a demifacet near the upper and lower borders on each side for the heads of two ribs.
  • Costal facet on the front of each transverse process for the tubercle of the rib with the same number.
  • Small, round vertebral foramen.
  • Long spine, pointing downwards and backwards and overlapping the one below.
  • Superior articular facets face backwards and slightly laterally.

Typical lumbar vertebra (L1 to L4)

  • Large kidney-shaped body, wider from side to side.
  • No foramen transversarium and no costal facets.
  • Triangular vertebral foramen, larger than thoracic but smaller than cervical.
  • Short, thick, quadrangular spine pointing straight backwards.
  • Thin transverse processes; a mamillary process on the back of each superior articular process and an accessory process at the root of the transverse process.
  • Superior articular facets face medially and backwards; inferior facets face laterally and forwards.

The atypical vertebrae examiners like

  • Atlas (C1): no body and no spine; a ring with two lateral masses carrying kidney-shaped superior facets for the occipital condyles and round inferior facets for the axis.
  • Axis (C2): the dens (odontoid process) projects upwards from the body and articulates with the anterior arch of the atlas.
  • C7 (vertebra prominens): long, non-bifid spine that you can feel at the base of the neck; the foramen transversarium is small and usually carries only veins, not the vertebral artery.
  • T1: a complete facet for the first rib and a demifacet for the second; a long horizontal spine.
  • T9: usually only an upper demifacet. T10: one complete facet near the upper border. T11 and T12: one complete facet on the body and no facet on the transverse process.
  • L5: the largest body, deeper in front than behind; massive transverse processes attached to the body as well as the pedicle.

Applied anatomy worth one line each

  • A fracture of the dens is dangerous because the dens lies in front of the spinal cord.
  • Intervertebral disc prolapse is commonest at L4-L5 and L5-S1, pressing on the nerve roots below.
  • The spines of C7, T1 and the upper lumbar vertebrae are the usual surface landmarks for counting; the line joining the highest points of the iliac crests crosses the L4 spine, used to place a lumbar puncture.
  • A cervical rib arising from C7 can compress the lower trunk of the brachial plexus and the subclavian artery.

Practise with the bones in order

Lay out the loose vertebrae from your bone set and arrange them from atlas to L5. Say the region aloud for each one using the three questions, then check it by the shape of the body and the spine. Both the unilateral and bilateral XBONZ bone sets include the full vertebral column, sacrum and coccyx. To see the column as a whole with its curves, rotate it in the free 3D skeleton in the XBONZ Anatomy Lab.

This is a revision aid. Check it against your course textbook and what your department teaches.

Shop skeleton models Open the 3D Anatomy Lab

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