The Dural Venous Sinuses

Key points

• • The dural venous sinuses are venous channels lying between the two layers of the dura mater; they have no valves and drain blood from the brain, skull and meninges.
• • The superior sagittal sinus runs along the top midline and takes in cerebrospinal fluid through the arachnoid granulations as well as venous blood.
• • The superior sagittal, straight and (often) occipital sinuses meet near the back of the skull at the confluence of sinuses.
• • From the confluence, blood passes through the paired transverse sinuses, then the sigmoid sinuses, and leaves the skull as the internal jugular veins.
• • The cavernous sinuses on each side of the pituitary are special because important nerves and the internal carotid artery run through or beside them.
• • Because facial veins connect to the cavernous sinus without valves, an infection on the face can spread backward and cause a dangerous cavernous sinus thrombosis.