Cavernous sinus

The cavernous sinus (Latin: sinus cavernosus) is a large, paired dural venous sinus. It is a channel filled with venous blood that is located against the lateral aspect of the body of the sphenoid bone on each side of the sella turcica.

The cavernous sinus extends from the medial end of the superior orbital fissure to the apex of the temporal bone's petrous part. It flows into the petrosal sinuses (superior and inferior) that further drain into the sigmoid sinus. The left and right cavernous sinuses are connected by the intercavernous sinuses (anterior and posterior).

The cavernous sinus collects venous blood from the following vessels:

• Superior ophthalmic vein
• Inferior ophthalmic veins
• Basilar plexus
• Superficial middle cerebral vein
• Inferior cerebral vein
• Sphenoparietal sinus

And occasionally from:

• Central retinal vein
• Frontal tributary of the middle meningeal vein

The cavernous sinus accommodates the internal carotid artery along with the internal carotid plexus (sympathetic nerves that surround the cavernous part of the internal carotid artery), and transmits several cranial nerves to two openings of the skull - the superior orbital fissure and foramen rotundum.

The nerves found in the cavernous sinus are the oculomotor (CN III), trochlear (CN IV), abducens (CN VI) nerves, as well as the ophthalmic (CN V1) and maxillary (CN V2) nerves - divisions of the trigeminal nerve (CN V). The internal carotid artery and the abducens nerve traverse the cavernous sinus, while the oculomotor, trochlear, ophthalmic and maxillary nerves are located within the lateral wall of the sinus.