The structure indicated is the parietal bone of the skull.

The parietal bone is one of 8 bones which form the calvaria (the part of the skull which contains the brain). The calvaria consists of:

• 2 parietal bones
• 2 temporal bones
• Frontal bone
• Sphenoid bone
• Ethmoid bone
• Occipital bone

The parietal bone articulates anteriorly with the frontal bone at the coronal suture. Inferiorly it articulates with the temporal bone at the squamous suture. Posteriorly it articulates with the occipital bone via the lamboid suture. It has a small articulation with the sphenoid bone via the sphenoparietal suture at pterion. The parietal bone articulates with the contralateral parietal bone via the sagittal suture.

The parietal bone has the following borders:

• Sagittal border
• Frontal border
• Squamous border
• Occipital border

The parietal bone has the following angles:

• Frontal angle
• Sphenoidal angle
• Occipital angle
• Mastoid angle

Learn more about the bones of the skull in this tutorial