Spinal cord vascularity. IV. The spinal cord arteries in the rat.

The present investigation has shown that the anatomy of the spinal cord arteries in the rat and in man is closely related but not identical. The main differences are: (1) The poor supply of radicular arteries to the lower cervical and upper thoracic segments of the cord is more marked in the rat, (2) the great ventral radicular artery of Adamkiewicz is less subjected to variations in position in the rat, (3) penetrating branches from the pial arterial plexus are absent in the rat, (4) surface anastomoses between the ventral and the dorsal spinal arteries do not occur in the rat except occasionally at the lower end of the cord. Intramedullary arterial anastomoses in the lumbosacral cord of the rat seems to be species specific.