Vault of the Skull

Study Notes

The internal surface of the vault shows coronal, sagittal, and lambdoid sutures.
A shallow sagittal groove lodges the superior sagittal sinus in the midline.
Granular pits on each side of the groove lodge the lateral lacunae and arachnoid granulations.
Narrow grooves are present for the anterior and posterior divisions of the middle meningeal vessels.

The interior of the base of the skull is divided into three cranial fossae: anterior, middle, and posterior.
The anterior cranial fossa lodges the frontal lobes of the cerebral hemispheres.
The anterior cranial fossa is bounded anteriorly by the inner surface of the frontal bone.
The lesser wing of the sphenoid separates the anterior and middle cranial fossae.

The median part of the anterior cranial fossa is limited posteriorly by the groove for the optic chiasma.
The floor of the fossa is formed by the ridged orbital plates of the frontal bone laterally and by the cribriform plate of the ethmoid medially.
The crista galli is a sharp upward projection of the ethmoid bone in the midline for the attachment of the falx cerebri.
The foramen cecum is a small aperture between the crista galli and the crest of the frontal bone for the transmission of a small vein from the nasal mucosa to the superior sagittal sinus.

The middle cranial fossa consists of a small median part and expanded lateral parts.
The median raised part is formed by the body of the sphenoid.
The expanded lateral parts form concavities on either side, which lodge the temporal lobes of the cerebral hemispheres.
The floor of each lateral part of the middle cranial fossa is formed by the greater wing of the sphenoid and the squamous and petrous parts of the temporal bone.