Diploic veins

The diploic veins are large, thin-walled valveless vessels that channel between inner and outer calvaria of the skull. They develop fully by two years after birth. The diploic veins drain this area into the dural venous sinuses. The four major types of diploic veins found on each side of the head are frontal, anterior temporal, posterior temporal, and occipital diploic veins.