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Dark bone
Last reviewed: 06.07.2025
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Parietal bone(os parietale) paired, wide, convex outward, forms the upper-lateral sections of the cranial vault. The parietal bone has 4 edges: frontal, occipital, sagittal and squamosal. The frontal edge borders the posterior surface of the frontal squama, the occipital edge - with the occipital squama. The two parietal bones are connected to each other with the help of the sagittal edge. The lower, squamosal edge is obliquely cut, covered by the squama of the temporal bone. The parietal bone has 4 angles: the anterior-superior frontal angle, the posterosuperior occipital angle, the anterior-inferior sphenoid angle and the posteroinferior mammillary angle.
On the concave surface along the entire upper edge of the parietal bone from front to back there is a groove of the superior sagittal sinus. Along this groove there are depressions of different sizes - granulation pits (foveolae granulores) - imprints of outgrowths of the arachnoid membrane of the brain. In the area of the mastoid angle there is a deep groove of the sigmoid sinus (sulcus sinus sigmoidei). On the inner surface of the bone there are clearly defined arterial grooves (sulci arteriosi). In the central part of the convex outer surface of the bone the parietal tubercle (tuber parietale) is noticeable, and under it - the upper and lower temporal lines (lineae temporales superior et inferior), running almost parallel along the entire length of the bone.
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