Page 344 - Clinical Anatomy

ECA5 7/18/06 6:51 PM Page 329

The vertebral column 329

Nucleus pulposus
Interspinous and
supraspinous
Annulus fibrosus ligaments
Ligamentum
A 'prolapsed disc'
flavum

Posterior longitudinal
(a) Anterior ligaments

Intervertebral disc
with central nucleus
pulposus

Termination of
spinal cord
Fig. 233◊(a) Longitudinal
section through the Sacral
lumbar vertebrae promontory
showing a normal and a
prolapsed intervertebral
disc. (b) MRI through a
normal lumbar spine and
sacrum. Note the
excellent anatomical Termination
details. (b) of dural sac

intervertebral discs constitute approximately a quarter of the length of the
spine as well as accounting for its secondary curvatures.
In old age, the discs atrophy, with resulting shrinkage in height and
return of the curvature of the spine to the C shape of the newborn.

Clinical features

1◊◊Fractures of the spine most commonly involve T12, L1 and L2. The
cause is usually a flexion–compression type of injury (for example, a fall
from a height landing on the feet or buttocks, or a heavy weight falling on
the shoulders), with resultant wedging of the involved vertebrae. If, in
addition to compression, there is forceful forward movement, one vertebra