Exam 4: Spinal Accessory and Hypoglossal nerves- Michaels Flashcards
What cervical levels make up the spinal accessory nerves?
C1-C5 lower motor neuron fibers
Where does CN 11 exit the skull?
Jugular foramen
What is CN11 responsible for?
motor innervation of trapezius and sternocleidomastoid
Where in a spinal cord section is CN 11’s nucleus?
posteriolateral portion of the anterior horn
What is the innervation to the spinal accessory nucleus? Where does it decussate?
Corticospinal tract that decussates at the pyramids of the midbrain
what is the predominant motor innervation to both the SCM and trapezius (contra or ipsilateral)?
SCM is predominantly ipsilateral, trapezius is mostly contralateral
Where does the hypoglossal nerve exit from the brainstem?
base of ventral medulla between pyramids and olive
What does the hypoglossal nerve innervate?
muscles of the ipsilateral tongue (critical for eating, breathing, speech and emesis)
Where is the nucleus of XII located?
near the midline (MOTOR) in floor of ventricle of the rostral medulla (look like the eyes of the monster in the medulla)
What can damage to the hypoglossal impact?
Chewing, swollowing, speaking
What does lower motor neuron damage of XII result in?
ipsilateral muscle atrophy of the tongue, tongue will deviate towards side of the lesion
What does upper motor neuron damage of XII result in?
tongue deviates away from the side of the upper motor neuron (contralateral)
