The neurocranium is a protective shell surrounding the brain and brain stem.
The viscerocranium (or facial skeleton) is formed by the bones supporting the face.
Except for the mandible, all skull bones are joined together by sutures—synarthrodial (immovable) joints.
The skull contains air-filled cavities called sinuses. Their functions are debatable, but may be related to lessening skull weight, contributing to voice resonance, and warming and moistening inspired air.
The protective vault surrounding the brain and brain stem.
The skull supports the musculature and
structures of the face and forms a protective cavity for the brain. The skull
is formed of several bones which, with the exception of the mandible, are
joined together by sutures—synarthrodial (immovable) joints.
Composition of the Skull
The adult human skull is comprised of
twenty-two bones which are divided into two parts of differing embryological
origin: the neurocranium and the viscerocranium.
The neurocranium forms the cranial cavity that surrounds and protects the brain and brainstem. The neurocranium is formed
from the occipital bone, two temporal bones, two parietal bones, the sphenoid,
ethmoid and frontal bones; they are all joined together with sutures.
The viscerocranium bones form the anterior
and lower regions of the skull and include the mandible, which attaches through
the only truly motile joint found in the skull. The facial skeleton contains
the vomer, two nasal conchae, two nasal bones, two maxilla, the mandible, two
palatine bones, two zygomatic bones, and two lacrimal bones.
The skull also contains the sinuses. These are air-filled cavities that contribute to lessening the weight of the skull with a minimal reduction in strength. They contribute to resonance of the voice and assist in the warming and moistening of air inhaled via the nose.