- The unpaired frontal
bone (L. frons = forepart) contributes the anterior one-third of the
- The paired parietal
bones (L. paries, pl. parieties=wall) contribute much of the remainder
of the dome.
- The unpaired occipital
bone (L. occiput = the back of the head) makes a small contribution to
the posterior region of the dome.
- The coronal suture
(L. corona=a crown) lies in a coronal plane between the frontal and left and
right parietal bones.
- 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
- 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:
- 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
PROMINENT LANDMARKS AND REFERENCE POINTS:
- 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.
- 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.