Editing Parietal bone (section)

== Surfaces ==

===External===
The external surface [Fig. 1] is convex, smooth, and marked near the center by an eminence, the [[parietal eminence]] (''tuber parietale''), which indicates the point where [[ossification]] commenced.

Crossing the middle of the bone in an arched direction are two curved lines, the superior and inferior '''temporal lines'''; the former gives attachment to the [[temporal fascia]], and the latter indicates the upper limit of the muscular origin of the [[temporal muscle]].

Above these lines the bone is covered by a tough layer of fibrous tissue – the [[epicranial aponeurosis]]; below them it forms part of the [[temporal fossa]], and affords attachment to the temporal muscle.

At the back part and close to the upper or sagittal border is the [[Parietal foramina|parietal foramen]] which transmits a vein to the [[superior sagittal sinus]], and sometimes a small branch of the [[occipital artery]]; it is not constantly present, and its size varies considerably.

===Internal===
The internal surface [Fig. 2] is concave; it presents depressions corresponding to the cerebral convolutions, and numerous furrows (grooves) for the ramifications of the [[middle meningeal artery]]; the latter run upward and backward from the sphenoidal angle, and from the central and posterior part of the squamous border.

Along the upper margin is a shallow groove, which, together with that on the opposite parietal, forms a channel, the [[sagittal sulcus]], for the [[superior sagittal sinus]]; the edges of the sulcus afford attachment to the [[falx cerebri]].

Near the groove are several depressions, best marked in the skulls of old persons, for the [[arachnoid granulations]] (Pacchionian bodies).

In the groove is the internal opening of the parietal foramen when that aperture exists.
{{Gallery|File:Gray132.png|'''Figure 1 :''' Left parietal bone. Outer surface.
|File:Gray133.png|'''Figure 2 :''' Left parietal bone. Inner surface.
|File:Left_parietal_boen_-_animation.gif|Left parietal bone (shown in green). Animation stops for a few seconds at inner and outer surface.
}}