The superior nuchal line limits the lower boundary of the perpendicularly flat occipital plane and creates a ridge that spreads out across the entire occiput. There, a faint, recognizable supreme nuchal line is located over this ridge. Centrally, the supreme nuchal line goes downwards at the bottom in order to form a distinct external occipital protuberance that is located somewhat over the situation of the superior nuchal ridge.
- Over this line, the bone is smooth as well as enclosed by the occipital belly of the occipitofrontalis muscle,
- Under this line, the bone is roughened by the attachments of the semispinalis capitis and obliquus capitis superior muscles.
The region of the line provides attachment for:
- Occipital belly of the occipitofrontalis
- Posterior portion of the sternocleidomastoid
- Splenius capitis
There is a faint supreme nuchal line which can be recognized over this ridge.