front matter 1

Top View Side View

AB

CD

EF

Medial motor

columns

Medial motor

column

extending

into the

sacral level

White matter

outlined

Gray matter

outlined

Central canal

(defines midlline)

Central and lateral

motor columns

(^6611)

77

88

99

Figure 22. The lumbar and sacral regions in specimen Y380-62 (GW10.5, CR 56 mm). The individual sections (911-1211) in this model are diagrammed
in Figure 18. The reconstructed length of the specimen is 10.5 mm after fi xation. Panels A, C, and E show the model from the top front, panels B, D,
and F from the upper right side. Panels A and B show both the white matter (outlined transparent envelope) and gray matter (inner transparent envelope)
around the central canal (gray-white solid) and motor columns (colored solids). Panels C and D show the gray matter (outlined transparent envelope)
around the central canal and motor columns. Panels E and F show the central canal and motor columns alone. Motor column 1 (cyan, axial muscle
motoneurons?) is located in the medial and central panels, ventral and dorsal tiers. The remaining motor columns (6-9) are limited to lumbar levels
(sections 911-1091). Column 6 (purple, motoneurons controlling hip movements?) is located in the central and lateral panels, ventral tier. Column 7
(pink, motoneurons controlling knee movements?) is located in the lateral panel, dorsal tier. Column 8 (violet, motoneurons controlling ankle and foot
movements?) is located in the lateral panel, dorsal and retrodorsal tiers. Column 9 (pale violet, motoneurons controlling hip movements?) is located in
the central panel, dorsal and ventral tiers.

FIGURE 22 GW10.5, CR 56 mm, Y380-62