External Surface Of The Parietal Bone, Posterior View

Description

Parietal bone anatomy is presented from a posterior viewpoint, emphasizing the convex external surface (facies externa) as it approaches the occipital region of the cranium. Along the superior margin, the serrated border for the sagittal suture (margo sagittalis) is visible near the midline, while the posteroinferior margin forms the lambdoid suture border (margo occipitalis) where the parietal meets the occipital bone. Subtle surface relief marks the parietal eminence (tuber parietale), and the superior and inferior temporal lines (lineae temporales) arc anteroinferiorly toward the temporal fossa, defining the attachment zones for temporalis fascia and muscle. Curvature dominates. The mastoid angle (angulus mastoideus) and occipital angle (angulus occipitalis) are readable as contour changes at the inferolateral and posterior aspects, respectively. Posterior parietal landmarks matter when you need to orient calvarial trauma and postoperative change relative to sutures and diploic thickness. Linear parietal fractures commonly propagate toward the sagittal or lambdoid sutures, and their relationship to these borders helps in describing fracture extension and in anticipating adjacent venous sinus proximity near the midline (superior sagittal sinus deep to the sagittal suture). For teaching craniosynostosis, the crisp suture margins provide an anchor for discussing premature lambdoid or sagittal fusion patterns and the resulting head shape changes, even though the pathology is evaluated clinically and on CT rather than from the bone surface alone. Neurosurgery and gross anatomy curricula can use this illustration to label parietal borders, angles, and temporal lines in calvaria labs, and radiology or trauma publications can pair it with CT bone window images to standardize surface terminology for posterior skull injuries. Anatomical accuracy verified by SciePro's Medical Advisory Board.