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.

Contents 1 Embryology 2 Borders 3 In other animals 4 See also 5 External links 6 References

[edit] Embryology

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

[edit] 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.

[edit] 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]

[edit] See also

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

[edit] External links

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

[edit] 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 As such, some of the information contained within it may be outdated.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

v • d • e Bones of head and neck: the neurocranium of the skull (TA A02.1.01-07, GA 2.129-155) Occipital Squama external (Inion/External occipital protuberance, Nuchal lines) · planes (Occipital, Nuchal) · internal (Cruciform eminence, Internal occipital protuberance, Sagittal sulcus, Internal occipital crest) Lateral parts Condyle (Condyloid fossa, Condylar canal) · Hypoglossal canal · jugular (Jugular process, Jugular tubercle) Basilar part Pharyngeal tubercle Other Foramen magnum (Basion, Opisthion) Parietal Parietal eminence · Temporal line · Parietal foramen Frontal Squama Frontal suture · Frontal eminence · external (Superciliary arches, Glabella) · foramina (Supraorbital, Cecum) · Zygomatic process · internal (Sagittal sulcus, Frontal crest) Orbital part Ethmoidal notch · Lacrimal fossa · Trochlear fovea · Frontal sinus · Frontonasal duct Temporal Squama Articular tubercle · Suprameatal triangle · Mandibular fossa · Petrotympanic fissure · Zygomatic process Mastoid part Mastoid foramen · Mastoid process (Mastoid cells) · Mastoid notch · Occipital groove · Sigmoid sulcus · Mastoid antrum (Aditus) Petrous part Carotid canal · Facial canal (Hiatus) · Internal auditory meatus · Cochlear aqueduct · Stylomastoid foramen fossae (Subarcuate fossa, Jugular fossa) · canaliculi (Inferior tympanic, Mastoid) · Styloid process · Petrosquamous suture (note: ossicles in petrous part, but not part of temporal bone) Tympanic part Suprameatal spine Sphenoid Surfaces Superior surface: Sella turcica (Dorsum sellae, Tuberculum sellae, Hypophysial fossa, Posterior clinoid processes) · Ethmoidal spine · Chiasmatic groove · Middle clinoid process · Petrosal process · Clivus Lateral surface: Carotid groove · Sphenoidal lingula Anterior surface: Sphenoidal sinuses Great wings foramina (Rotundum, Ovale, Vesalii, Spinosum) · Spine · Infratemporal crest · Sulcus for auditory tube Small wings Superior orbital fissure · Anterior clinoid process · Optic canal Pterygoid processes fossae (Pterygoid, Scaphoid) · pterygoid plates (Lateral, Medial) · Pterygoid canal · Hamulus Other Body · Sphenoidal conchae Ethmoid Plates Cribriform plate (Crista galli, Olfactory foramina) · Perpendicular plate Surfaces Lateral surface Orbital lamina · Uncinate process Medial surface Superior nasal concha · Superior meatus · Middle nasal concha · Middle meatus Labyrinth Ethmoid sinus · ethmoidal foramina (Posterior, Anterior)