Nerve · Head

Nerve of the pterygoid canal

Nervus canalis pterygoidei

Not a branch of anything, but a nerve formed where two others meet. The greater petrosal nerve, carrying parasympathetic fibres from the facial nerve, joins the deep petrosal nerve, carrying sympathetic fibres from the plexus wrapped around the internal carotid artery, and together they run forward through the pterygoid canal — a tunnel bored through the base of the sphenoid bone — to reach the pterygopalatine ganglion. It is the delivery route for the autonomic supply of the tear gland and the glands of the nose and palate, so it governs how wet those surfaces are. It also demonstrates something the rest of this file only hints at: fibres from one cranial nerve routinely finish their journey riding on the branches of another.