The dural venous sinuses are lined with endothelium and lack muscles and valves. They collect blood from the brain, meninges, orbit, inner ear and diploe. The superior sagittal sinus begins at the crista galli and ends at the internal occipital protuberance, draining into the confluence of sinuses. Infection from the scalp, nasal cavity or diploic tissue can lead to septic thrombosis and obstruct CSF absorption, causing increased intracranial pressure. The paired transverse sinuses and sigmoid sinuses carry blood through the posterior compartment of the jugular foramen before joining the internal jugular vein.