Bones of the Head
The bones of the head form a protective cavity around the brain. The bones of the head meet at joint lines called sutures. They are a type of fibrous joint, which are immovable.
The 22 bones of the skull can be divided in to two main categories: the cranium and the facial skeleton. The cranium encloses and protects the brain; whereas, the bones of the facial skeleton provides support to facial soft tissues. Neurovascular structures enter and leave the cranium through the cranial foramina.
The cranium can be divided further in to the calvarium and the cranial base. The calvarium is comprised of the frontal, occipital and two parietal bones, and the cranial base is comprised of the frontal, sphenoid, ethmoid, occipital, parietal and temporal bones.
The bones of the cranial base allow articulation with the first cervical vertebrae, as well as with the mandible to form the temporomandibular joint. The mandible is the strongest and largest bone of the face. The mandible forms the lower jaw and is the site of insertion for the lower teeth.
The sphenoid bone is a butterfly-shaped bone consisting of a body, and upper and lower wings. The sphenoid bone contains the sphenoid sinuses. The ethmoid bone forms the roof of the nasal cavity. Fibres from the olfactory nerve (CN1) pass through the ethmoid bone into the nasal cavity allowing the sense of smell. The temporal bone, located laterally, supports the temporal lobes, as well as containing the middle and inner parts of the ear.
The bones of the head create the bony orbits: symmetrical cavities which surround and protect the eye and associated structures. The bones of the head also give rise to the bony component of the nasal skeleton.
In this section, learn more about the bones of the head including: the skull, bony orbit, sphenoid bone, ethmoid bone, temporal bone, mandible, nasal skeleton and cranial foramina.