Definition
Diploic veins are a network of valveless veins located within the skull. They're found in the spongy bone (diploe) between the inner and outer layers of the skull. These veins connect the veins outside the skull with the dural sinuses inside the skull. ð They act as a drainage system for the skull bones. They don't have valves, so blood can flow in either direction. They are important for pressure regulation. They also play a role in potential routes for infection.