The Posterior Spinal Artery inclines downwards and inwards to get behind the spinal marrow, and descends parallel to its fellow of the opposite side, as far as the second lumbar vertebra. In this course it gives off branches analogous to those of the anterior spinal, anastomoses with the lateral spinal branches of the vertebral and ascendens colli, which pass through the spinal foramina, and with the minute branches given off from the artery of the opposite side : this artery sends many branches to the pia mater, and some delicate capillary branches to the spinal marrow: it is sometimes a branch of the inferior artery of the cerebellum.