Final answer:
The external occipital protuberance is a small protruding feature of the occipital bone at the back of the skull that serves as an attachment point for the nuchal ligament. This bone also houses the foramen magnum and articulates with the first cervical vertebra via occipital condyles.
Step-by-step explanation:
The external occipital protuberance is a small, midline bump located on the outside surface of the occipital bone at the posterior skull. This feature of the skull serves as an attachment site for the nuchal ligament of the posterior neck. The occipital bone, which forms part of the cranial cavity's base, also contains the foramen magnum for the spinal cord's exit and articulates with the first cervical vertebra via the occipital condyles. The superior nuchal line extends laterally from the external occipital protuberance and provides an attachment point for neck muscles, above which is covered only by the scalp.