Lumbar
Enlargement
Cervical
Enlargement
Thoracic
area
Sacral
area
Central canal
(defines midline)
Right Left
Medial motor columns
Central and
lateral motor
columns
(cervical)
Central and
lateral motor
columns
(lumbar)
Autonomic
motor column
Posterior
edge of
white
matter
Posterior
edge of
gray
matter
A
B
C
Anterior
edge of
white
matter Anterior
edge of
gray
matter
Anterior
edge of
gray
matter
Anterior edge
of gray matter
Figure 26. The entire spinal cord in specimen Y68-65 (GW14,
CR 108 mm) as viewed from the front and top (A, B, C, this page) or
the upper right side (D, E, F, facing page). The front edge of the recon-
struction is section 701, the back edge is section 2101. The total length
after fi xation is 49 mm. In this and the following reconstructions, the
spinal cord has been enlarged 3 times more crosswise than lengthwise.
Otherwise, the model is too long to see the various motoneuron columns
clearly. Solid outlines defi ne the outer edges of the white matter (trans-
parent envelope, A and D); dashed outlines defi ne the outer edges of the
gray matter (less transparent envelope, A, B and D, E). The gray-white
solid in panels A-E is the central canal. The colored solids in panels A-E
are ventral horn motor columns.
There are 15 pairs of motor columns on each side of the ventral horn in
this specimen. The medial motor columns (cyan) are split in the thoracic
region and extend into the lumbar enlargement up to section 1901 and
then disappear. The remaining motor columns are in the ventral, central,
and lateral sectors. There are eight central and lateral motor columns in
the cervical region (light brown, orange, yellow shades). The lumbar
enlargement is large in this specimen and contains six central and lateral
motor columns (purple, violet, magenta shades). The top and side views
in panels C and F show the intertwined arrangement of the motor columns
in the cervical and lumbar enlargements. The autonomic motor columns
(green) in the lateral horn of the thoracic and upper lumbar regions are
also reconstructed in this specimen.
FIGURE 26 GW14, CR 108 mm, Y68-65