Occipital Bone

The occipital bone forms the back and base of the skull. It curves around the foramen magnum — the large opening where the spinal cord passes through to join the brain — and it has two smooth knobs (condyles) that rest on the first neck vertebra, letting you nod your head.

Key facts

The occipital bone contains the foramen magnum, the largest opening in the skull.
Its two condyles sit on the atlas (first neck vertebra) to form the nodding joint.
Inside, it cradles the cerebellum, the part of the brain that coordinates movement.
The bump at the back of the head (inion) is a landmark on this bone.
Strong neck and back muscles attach along its curved nuchal lines.

What can go wrong

Injuries to the back of the head can fracture the occipital bone, and because the brainstem sits just inside it, such injuries are taken seriously. Some people are born with variations at the joint between this bone and the spine that narrow the space for the spinal cord and need specialist assessment.

Related procedures & tests

CT head scan

Related symptoms

Neck pain

Related muscles

Watch: related videos

▶ WatchForamen magnum neurofibroma ▶ WatchForamen magnum neurofibroma video

Frequently asked questions

What passes through the hole in the occipital bone?

The foramen magnum transmits the spinal cord where it becomes the brainstem, the vertebral arteries that supply the brain, and parts of the accessory nerve. It is the main gateway between the skull and the spinal canal.

Which head movement does the occipital bone allow?

Nodding. The occipital condyles rock on the atlas below them, producing the yes movement of the head; turning the head side to side happens one joint lower.

Educational information only. This atlas explains normal anatomy and describes conditions in general terms; it is not medical advice and does not replace assessment by a qualified clinician. If you have symptoms that worry you, seek medical care.