The microvasuculature of corrosion casts of peripheral nerves and lumbosacral nerve roots in monkey were examined by scanning electron microscopy. Peripheral nerves had two different vascular systems that were intraneural capillaries and extraneural plexus. The main compensation mechanism which had a great role on a blood supply was latter one. However, the vascular system of lumbosacral nerve roots had few “shunt structure”, and was consisted of constant close network of capillaries, probably which was main compensation mechanism.
