The skull consists of 22 bones. It is divided into two main parts; the neurocranium (the bones housing the brain), and the viscerocranium (facial skeleton).
- The neurocranium covers and protects the brain and meninges. It is formed by 2 paired, and 4 singular bones.
- The viscerocranium forms the facial skeleton, and it consists of 6 paired, and 2 singular bones.
- The ethmoid bone participate in both the neuro- and viscerocranium. It is classically considered to be a part of the neurocranium, and some sources