Cranial nerves emerge directly from the brainor brainstem while spinal nerves emerge fromsegments ofthe spinal cord. There are a total of twelvecranial nerves conventionally recognized. Thenerves from the thirdonward arise from the brainstem. Except for thetenth and the eleventh nerve, they primarilyserve the motorand sensory systems of the head and neck region.However, unlike peripheral nerves which areseparated to achieve segmental innervation, cranial nerves aredivided to serve one or a few specific functionsin a widerange of anatomical regions.