front matter 1

A

B

C

D E F G H I J

Central canal

(defines midlline)

Central and

lateral

motor columns

Medial motor

columns

Autonomic

motor columns

White matter

outlined

Gray matter

outlined

Columns 1 and 11

Columns 1 and 12

Columns 1 and 13

Columns 1 and 14

Columns 1 and 15

Columns 1 and

Autonomic

Columns 1 and 10

11

Central

canal

1010

(^12121111)

1313 1414

15

Figure 29. The lumbar and sacral regions

in specimen Y68-65 (GW14, CR 108 mm).

The individual sections (1781-2101) in

this model are diagrammed in Figure 25.

The reconstructed length is 11.2 mm after

fi xation. All panels show the model from

the top front. Panel A shows both the

white matter (outlined transparent enve-

lope) and gray matter (inner transparent

envelope) around the central canal (gray-

white solid) and motor columns (colored

solids). Panel B shows the gray matter

(outlined transparent envelope) around the

central canal and motor columns. Panel C

shows the central canal and all the motor

columns. The small side panels (D-J)

show various subsets of motor columns

with the central canal.

Figure 30. A continuation of the previous fi gure in the same specimen except that all panels show either the entire model or parts of it in a side view.
Motor column 1 (cyan, medial panel, ventral tier) may innervate axial muscles. It is bifurcated in the fi rst section (1781) and single in sections 1821 to

1861. The autonomic motor column (green) is in the fi rst two sections of the model (1781-1821) and contains the most posterior neurons that innervate
      the sympathetic ganglia. The remaining motor columns (10-15) are present only at lumbar levels or upper sacral levels (sections 1781-2061). Columns

FIGURE 29 GW14, CR 108 mm, Y68-65