Left pterygoid process, posterior view. The posterior aspect of the vidian canal opens up intothe foramen lacerum. The foramen ovale is located just lateral to the foramen lacerum, and they are separated by the mandibular strut, which is occasionally pierced or grooved by a sphenoidal emissary vein also known as Vesalius vein. The pterygoid tubercle is a small prominence situated just inferior to the posterior opening of the vidian canal. The medial pterygoid plate continues superiorly as the lacerum process, which forms the posteromedial aspect of the foramen lacerum, and continues anteriorly as the vaginal process. The pterygosphenoidal fissure, between pterygoid process and floor of sphenoid, forms a defined groove that opens up into the foramen lacerum. The petrosphenoidal fissure, between petrous apex and greater wing of sphenoid, also ends up in the lacerum. The scaphoid fossa is below the pterygoid tubercle and gives origin to the tensor veli palatini muscle. The pterygoid fossa lodges the origin of medial pterygoid muscle. (Image courtesy of JC Fernandez-Miranda)