Occipital bone

Os occipitale

Definition

The occipital bone is an essential part of the skull’s back, forming the posterior part of the skull’s base. Its upper surface helps create the floor of the posterior cranial fossa, crucial for housing the cerebellum and the brainstem.

Its anatomy is marked by several important features that provide support, brain protection, and enable head movements. The focal point of the occipital bone is the foramen magnum, which is a large opening that allows the spinal cord to connect with the brainstem. Flanking this opening are the occipital condyles, the two structures that join with the first cervical vertebra, the atlas, to allow nodding and turning of the head.

On the outside, the occipital bone has superior and inferior nuchal lines, ridges that act as attachment sites for neck muscles, helping stabilize and move the head. The external occipital protuberance is a noticeable feature at the back of the head, and from it runs the external occipital crest down the middle of the bone to the posterior margin of foramen magnum. Inside the skull, similar structures include an internal occipital protuberance and crest, and grooves extending laterally from the internal protuberance for the transverse and sigmoid sinuses, which head towards the jugular foramen.

Through its design and connections, the occipital bone has a critical role in protecting the brain and enabling head and neck movements.

__________________________________________________________________

Text written by Muhammad A. Javaid, MD, PhD © 2024 IMAIOS.

  • Drake, R.L., Vogl, A.W. and Mitchell, A.W.M. (2009). ‘Chapter 8: Head and Neck’ in Gray’s anatomy for Students. (2nd ed.) Philadelphia PA 19103-2899: Elsevier, pp. 821 & 827.


Comparative anatomy in animals

Translations

Translations