In this section we will cover the dural venous sinuses and the veins which drain the head and neck.

THE DURAL VENOUS SINUSES

Click on the images above to see 2 different views of the dural venous sinuses

The image below shows the structure of the dural venous sinuses in more detail

The venous sinuses are located between the layers of the dura mater. They open up between the endosteal layer and the meningeal layer of the dura mater.

They are lined by endothelium but unlike veins they contain no valves. Notice the arachnoid granulations which protrude into this sinus. This allows for CSF to return to the venous system from the subarachnoid space.

The main function of these venous sinuses is to drain all venous blood from within the cranial cavity to the jugular foramen - the origin of the internal jugular vein. Draining into them are:

• Cerebral veins which cross the subdural space to get there. These are often referred to as bridging veins.
• Emissary veins penetrate the skull allowing connections to exist between the extracranial and intracranial environment (risky business!).
• Diploic veins which drain directly from the bones of the skull

Check out our video below for more detail on the dural venous sinuses: