BONES:

  1. The unpaired frontal bone (L. frons = forepart) contributes the anterior one-third of the dome.
  2. The paired parietal bones (L. paries, pl. parieties=wall) contribute much of the remainder of the dome.
  3. The unpaired occipital bone (L. occiput = the back of the head) makes a small contribution to the posterior region of the dome.

PRINCIPAL SUTURES:

  1. The coronal suture (L. corona=a crown) lies in a coronal plane between the frontal and left and right parietal bones.
  2. The sagittal suture (L. sagitta=arrow) is the straight (arrow-like) suture between left and right parietal bones.   It lies in and gives its name to the midsagittal plane.
  3. The lambdoidal suture, between the occipital and left and right parietal bones, is shaped like the lambda, the 11th letter of the Greek alphabet.  Only its summit is seen in this view of the skull.

NEUROVASCULAR EXIT PORTALS:

  1. The parietal emissary foramina transmit emissary veins that are valveless and normally drain blood from the scalp into the dural sinuses in the cranium.  Clinically they represent potential paths of infection leading into the brain.

PROMINENT LANDMARKS AND REFERENCE POINTS:

  1. Bregma (Gr.=front of the head) is the point of intersection of the coronal and sagittal sutures.  This was the location of the anterior fontanelle.
  2. Lambda (Gr.=11th letter of the alphabet) is the point of intersection of the sagittal and lambdoidal sutures.  This was the location of the posterior fontanelle.