Bone · Head

Parietal

Os parietale

A pair of curved plates that make up most of the roof and upper sides of the braincase, one on each side, meeting along the midline at the top of the head. Each parietal meets the frontal bone in front, the occipital behind, the temporal below and the greater wing of the sphenoid at its lower front corner, and every one of those joints is a suture — an interlocking seam, not a moving joint. Its outer surface is crossed by two faint curved ridges: the lower, the inferior temporal line, marks the upper limit of the temporalis — the fan-shaped chewing muscle that covers the side of the head — while the superior temporal line above it takes the sheet of fascia covering that muscle. So the upper side of the skull is not bare bone under the scalp; the parietal is the surface a chewing muscle and its fascia sweep across on their way down to the jaw.