Innervation of human trigeminal nerve blood vessels.

Film preparations and histological sections of human trigeminal nerve impregnated with silver nitrate and treated according to Falck-Hillarp revealed a rich innervation within the intraneural blood vessels. Highly diverse and complex neural interconnections were noted in the arterioles and venules of the trigeminal ganglion capsule as well as in the epineurium and external layers of the perineurium of the trigeminal nerve branches. Neural plexuses were detected on the vessel walls within these layers. Sensory innervation of the neural blood vessels was mainly relegated to polyvalent tissue-vascular receptors with adrenergic neural plexuses encountered on the walls of the intraneural vessels.