Developmental and circulatory profile of the diploic veins

► The diploic veins are located in the diploic space of the cranial bone. ► The total area of the diploic veins showed a continuous, age-dependent development. ► The confocal microscope images demonstrated that the diploic veins were connected to the dural vessel. ► The red blood cell (RBC) velocities in the diploic veins in vivo revealed RBCs with a significantly high velocity at the entrance route to the diploic veins from the dural vessels. ► We detected communications between the diploic veins and intra-cranial circulation in living animals.