Internal table of calvaria

The inner layer of the cranial bones is known as the internal table of calvaria. It is a dense cortical bone but is thin and fragile in nature. Additionally, the calvaria also includes an outer layer called the external table of the calvaria, which is also a cortical bone, however, in contrast to the internal table, the external table is thick and strong. Together, these two layers enclose a spongy (or cancellous bony) region called the diploe. The internal table of calvaria is oriented towards the endosteal layer of the dura mater, while the external table faces the periosteum.

Various distinct bony ridges, grooves, and pits can be found on the inner surface of the internal table of calvaria. These features include the groove for the superior sagittal sinus, small depressions known as granular foveolae, markings for cerebral gyri, and elevations for cerebral sulci. Additionally, you can find various venous and arterial grooves on this surface.