Cranial nerve III: The third cranial nerve is the oculomotor nerve. The cranial nerves emerge from or enter the skull (the cranium), as opposed to the spinal nerves which emerge from the vertebral column. There are twelve cranial nerves.
- The upper eyelid muscle which raises the eyelid;
- The extraocular muscle which moves the eye inward; and
- The pupillary muscle which constricts the pupil.