Preganglionic parasympathetic fibres exit the geniculate ganglion as the greater petrosal nerve. It enters the middle cranial fossa through the hiatus of the facial canal, along with the petrosal branch of the middle meningeal artery. It enters the pterygoid canal, where it joins the deep petrosal nerve (a sympathetic nerve) to form the nerve of the pterygoid canal, which passes through the pterygoid canal to reach the pterygopalatine ganglion.