The nerve of the pterygoid canal (Vidian nerve) is formed by the union of the (parasympathetic) greater petrosal nerve and (sympathetic) deep petrosal nerve within the cartilaginous substance filling the foramen lacerum. From the foramen lacerum, the nerve of the pterygoid canal passes through the pterygoid canal to reach the pterygopalatine fossa, ending at the pterygopalatine ganglion.
Structure
The nerve of the pterygoid canal forms from the junction of the greater petrosal nerve and the deep petrosal nerve within the foreamen lacerum. This combined nerve exits the foramen lacerum and travels to the pterygopalatine fossa through the pterygoid canal in the sphenoid.
The nerve of the pterygoid canal contains axons of both sympathetic and parasympathetic axons, specifically;
The preganglionic parasympathetic axons synapse in the pterygopalatine ganglion, which contains the postganglionic neurons which provide secretomotor innervation to the lacrimal gland, as well as the nasal and palatine glands.
The postganglionic sympathetic axons do not synapse in the pterygopalatine ganglion, they travel on the branches of the maxillary nerve to provide sympathetic innervation to blood vessels.
Additional images
Alveolar branches of superior maxillary nerve and pterygopalatine ganglion.
Diagram of the cervical sympathetic.
Depicts nerve branches that are involved in the autonomic innervation of the lacrimal gland. The terminal parts of the pathway are variable between individuals and differ for the other glands of the deep face.
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