Page:Structure and functions of the body; a hand-book of anatomy and physiology for nurses and others desiring a practical knowledge of the subject (IA structurefunctio00fiskrich).pdf/56

 line above and join the frontal and occipital bones at either end, while below they touch upon the temporal bones, the temporal muscles being attached in part along their lower surface. These muscles are inserted into the coronoid process of the lower jaw, which they thus help to raise and to retract.

—Front view of the skull. (After Sobotta.)

The occipital bone is at the base of the skull and at birth consists of four pieces. In the lower, anterior part is the foramen magnum, an oval opening through which the spinal cord passes from the skull down into the spinal canal. Half way between the foramen and the top of the bone is the external occipital protuberance for the attachment of the ligamentum nuchæ which holds the head erect. The inner side of the bone is deeply concave and is divided by a cross-shaped grooved ridge into four fossæ, the internal occipital protuberance being situated