Extracranial Venous Drainage

The orbital veins develop from the primitive maxillary and supraorbital veins, tributaries of the cavernous sinus developed from the pro-otic sinus (see also embryology, Chap. 9). The final result of the embryological evolution of these venous channels is the superior and inferior ophthalmic veins, draining posteriorly in the cavernous sinus. They are connected anteriorly with the facial and frontal veins. Other connections are those with the pterygoid plexus (see also Sects. “Superior and Inferior Ophthalmic Veins” 9.3.11 and 9.3.12) (Drawing in Fig. 10.1).