Final answer:
The external occipital protuberance is a small protrusion on the posterior skull that serves as an attachment site for neck ligaments. It is located at the caudal end of the occipital bone, which also features the foramen magnum and occipital condyles for spinal cord exit and skull articulation with the spine.
Step-by-step explanation:
The external occipital protuberance is a small bump located at the midline on the posterior skull, at the caudal end of the occipital bone. This protuberance serves as an attachment site for the nuchal ligament of the posterior neck. Lateral to the external occipital protuberance are the superior nuchal lines, which are paired bony lines that extend laterally and represent the most superior point of muscle attachment from the neck to the skull. The occipital bone also contains the large opening of the foramen magnum, through which the spinal cord exits the skull, and the occipital condyles that form joints with the first cervical vertebra, supporting the skull atop the vertebral column.