Question | Answer |
What is the nucleus of CN XI? | Nucleus ambiguus and disperse cell bodies/ medulla & cervical segments |
Where does CN XI exit? | post olivary sulcus |
What are the branches of CN XI? | Splits into a cranial and spinal root |
What is the cranial accessory function of CN XI? | Joins the vagus nerve to supply the muscles of the pharynx, larynx and soft palate |
What is the spinal accessory function of CN XI? | Motor to the SCM & trap muscles |
What are the symptoms of a lesion to CN XI? | Inability to rotate head & shrug shoulder |
Where do CN IX, X & XI exit? | Jugular foramen |
What is the nucleus of CN XII? | Hypoglossal nucleus at the level of the medulla |
WHere does CN XII exit? | Pre-olivary sulcus |
What is the function of CN XII? | Motor to all of the tongue muscles (muscles that end with glossus) except palatoglossus which is supplied by the vagus like all palatine muscles. |
What are the symptoms of of a lesion to CN XII? | Ipsilateral tongue paralysis & atrophy |
Where does CN XII exit from the skull? | Hypoglossal canal |
Why are supranuclear (UMN) symptoms of CN rare? | Because the corticobulbar tract innervates most of them bilaterally. |