frontal bone

Bone: Frontal bone
Frontal bone at birth.
Latin	os frontale
Gray's	subject #33 135
Articulations	twelve bones: the sphenoid, the ethmoid, the two parietals, the two nasals, the two maxillæ, the two lacrimals, and the two zygomatics
MeSH	Frontal+Bone

The frontal bone is a bone in the human skull that resembles a cockleshell in form, and consists of two portions:

• a vertical portion, the squama frontalis, corresponding with the region of the forehead.
• an orbital or horizontal portion, the pars orbitalis, which enters into the formation of the roofs of the orbital and nasal cavities.

Embryology

The frontal bone is presumed to be derived from neural crest cells.^[1]

Borders

The border of the squama frontalis is thick, strongly serrated, bevelled at the expense of the inner table above, where it rests upon the parietal bones, and at the expense of the outer table on either side, where it receives the lateral pressure of those bones; this border is continued below into a triangular, rough surface, which articulates with the great wing of the sphenoid. The posterior borders of the orbital plates are thin and serrated, and articulate with the small wings of the sphenoid.

In other animals

In most vertebrates, the frontal bone is paired, rather than presenting the single, fused structure found in humans. It typically lies on the upper part of the head, between the eyes, but in many non-mammalian animals it does not form part of the orbital cavity. Instead, in reptiles, bony fish and amphibians it is often separated from the orbits by one or two additional bones not found in mammals. These bones, the prefrontals and postfrontals, together form the upper margin of the eye sockets, and lie to either side of the frontal bones.^[2]

See also

• Ossification of frontal bone
• Bone terminology
• Terms for anatomical location

External links

• SUNY Labs 23:os-0101
• Roche Lexicon - illustrated navigator, at Elsevier 34256.000-1

References

This article was originally based on an entry from a public domain edition of Gray's Anatomy. As such, some of the information contained herein may be outdated.

v • d • e The Bones which form the Orbit Frontal bone • Zygomatic bone • Maxillary bone • Sphenoid bone • Ethmoid bone • Palatine bone • Lacrimal bone