Anatomy of the skull

Composition of the Skull

The skull is divided into:

• The neurocranium - skull base and calvaria
• The viscerocranium - facial skeleton.

The skull is composed of 22 bones (excluding the middle ear ossicles).

• 8 forming the cranium
• 14 forming the face.

The orbits (eye sockets) lie between the calvaria (skull cap) and the facial skeleton and are formed by contributions from 7 different bones.

Skull bones

Neurocranium		Viscerocranium
Ethmoidal	1	Zygomatic	2
Frontal	1	Vomer	1
Occipital	1	Inferior nasal concha	2
Sphenoidal	1	Maxilla	2
Parietal	2	Nasal	2
Temporal	2	Palatine	2
		Lacrimal	2
		(Mandible)	1
Total = 22	8		14

Major Sutures of the Skull

Most bones of the skull are bound by sutures, a type of fibrous joint that fuses with age and becomes immobile.

• Coronal suture separates frontal and parietal bones.
• Sagittal suture separates two parietal bones.
• Lambdoid suture separates parietal and temporal bones from occipital bones.
• Squamous suture separates the squamous part of the temporal bone from the parietal bone.
• Sphenosquamous suture separates the squamous part of the temporal bone from the greater wing of sphenoid bone.
• Metopic suture between two frontal bones is largely obliterated with fusion of frontal bones