The cavernous sinuses are large, venous channels located at the base of the skull, on either side of the pituitary gland. They play a crucial role in draining blood from the brain and surrounding structures. These sinuses are named for their cavernous appearance and are filled with blood rather than air. Each cavernous sinus contains important nerves and arteries, including the internal carotid artery and several cranial nerves. They are involved in regulating blood flow and can be affected by various medical conditions, such as cavernous sinus thrombosis, which can lead to serious complications if not treated promptly.