Cranial bones

Definition

Cranial bones are the bones that form the protective encasement of the brain, collectively known as the cranium. They include eight distinct bones that are fused together at immovable joints called sutures.

5 Must Know Facts For Your Next Test

1. The eight cranial bones include one frontal bone, two parietal bones, two temporal bones, one occipital bone, one sphenoid bone, and one ethmoid bone.
2. The cranial bones protect the brain and support structures such as the eyes and ears.
3. Sutures are fibrous joints where cranial bones fuse together; major sutures include coronal, sagittal, lambdoid, and squamous.
4. Fontanelles are soft spots on a baby's skull where ossification is not yet complete; these eventually harden into sutures.
5. The sphenoid bone is unique because it articulates with all other cranial bones.

Review Questions

Related terms

Sutures:

Fibrous joints where cranial bones fuse together during development.

Fontanelles: Soft spots on an infant's skull where ossification has not yet occurred.

Foramen Magnum: A large opening in the occipital bone through which the spinal cord connects to the brain.