Bone
Occipital bone
Posterior skull base around the foramen magnum
High-yield
The foramen magnum transmits the medulla–spinal cord junction, vertebral arteries and ascending spinal roots of CN XI. The occipital condyles participate in the nodding movement at the atlanto-occipital joints.
Overview
The occipital bone forms the back of the cranium and much of the posterior cranial floor. It surrounds the foramen magnum and carries paired condyles that connect the skull to the atlas.
Reference facts
- Bone type
- Flat cranial bone with complex basal parts
- Key landmarks
- Foramen magnum, occipital condyles, external occipital protuberance and nuchal lines, hypoglossal canals, and the occipital contribution to the clivus
- Articulations
- Parietal bones at the lambdoid suture; temporal bones, sphenoid and atlas
Clinical correlation
A dangerous pressure gradient can displace the cerebellar tonsils downward through the foramen magnum. Compression of the lower brainstem in acute tonsillar herniation can impair breathing and other vital functions.
Frequently asked questions
What type of bone is the occipital bone?
The occipital bone is a flat cranial bone with complex basal parts bone.
What does the occipital bone articulate with?
Parietal bones at the lambdoid suture; temporal bones, sphenoid and atlas.
What are the key landmarks of the occipital bone?
Foramen magnum, occipital condyles, external occipital protuberance and nuchal lines, hypoglossal canals, and the occipital contribution to the clivus.