The cavernous sinus is a relatively large venous channel formed by a splitting of the dura mater on each side of the body of the sphenoid bone. The cavernous sinus extends from the medial end of the superior orbital fissure to the petrous portion of the temporal bone.

Where are the cavernous sinuses located?

The cavernous sinus (Figs 7.59–7.61), one on each side, situated on the body of the sphenoid bone, extends from the superior orbital fissure to the apex of the petrous temporal bone. Medially, the cavernous sinus is related to the pituitary gland and the sphenoid sinus.

Why is the cavernous sinus of clinical importance?

The cavernous sinus is a true dural venous sinus and not a venous plexus. It is clinically important because of its location, its close relationship to several cranial nerves and the internal carotid artery, and the complex of veins without valves that drain from and to the paired cavernous sinuses.