Figure 1.

A nerve root and its supplying artery of a normal rabbit are represented, which were reconstructed three dimensionally by using consecutive sections of the same artery specimen. The reconstructed artery is accepted as a cylinder, and its surface area is calculated as: S = 2∏rh; the endothelial cell density was calculated in a part of ANs. Volumetric changes of the ANs were calculated as the volume of the cylinder-shaped artery by the following formula: V = ∏r²h. Vascular luminal changes of the arteries were calculated by using volume changes of the ANs instead of changes in vessel diameter.