Brain Stem + Cranial Nerves

Question 1

what are the 3 major subdivisions of the brainstem?

Answer 1

1. medulla
2. pons
3. midbrain

Question 2

what is a key concept about the caudal medulla?

Answer 2

• resembles rostral spinal cord

- same pathways for sensory + motor nuclei

Question 3

CN 1

Answer 3

ofactory

Question 4

CN 2

Answer 4

Optic

Question 5

CN 3

Answer 5

Oculomotor

Question 6

CN 4

Answer 6

Trochlear

Question 7

CN 5

Answer 7

Trigeminal

Question 8

CN 6

Answer 8

Abducens

Question 9

CN 7

Answer 9

Facial

Question 10

CN 8

Answer 10

Vestibulocochlear

Question 11

CN 9

Answer 11

Glossopharyngeal

Question 12

CN 10

Answer 12

Vagus

Question 13

CN 11

Answer 13

Acessory

Question 14

CN 12

Answer 14

Hypoglossal

Question 15

which cranial nerves do we encounter in the medulla?

Answer 15

12, 11, 10, 9, 5

Question 16

which cranial nerves do we encounter in the pons?

Answer 16

6, 7, 8

Question 17

Trigeminal Nerve (5)

Answer 17

1. motor
2. sensory
   - pain + temp (face)
   - tactile
3. position sense (jaw)

Question 18

what are the 3 divisions of the trigeminal nerve?

Answer 18

1. ophthalmic
2. maxillary
3. mandibular

Question 19

what type of sensory deficits are involved with the trigeminal nerve?

Answer 19

-loss of pain + temp on face
-loss of touch-pressure on face
-loss of position sense in jaw
(all ipsilateral)

Question 20

what reflex is related to a deficit in the trigeminal nerve?

Answer 20

corneal reflex

Question 21

what are the motor deficits in a damaged trigeminal nerve?

Answer 21

ipsilateral muscle paralysis in jaw

Question 22

what kind of nerve is the hypoglossal nerve?

Answer 22

strictly motor nerve that supplies muscle and tongue

Question 23

what is a result of lesions in the hypoglossal nerve?

Answer 23

ipsilateral paralysis atrophy of tongue

Question 24

what are the two parts of the accessory nerve?

Answer 24

1. cranial part (assist 9 and 10

2. spinal (muscles in neck)

Question 25

what is clinical testing for the accessory nerve?

Answer 25

-spinal part + innervation of shoulder muscles

Question 26

what are the 4 functional components of the vagus nerve?

Answer 26

1. motor (pharynx + larynx) 2. parasympathetic (thorax + abdomen) 3. sensory (pharynx + larynx) 4. taste (epiglottis in tongue)

Question 27

what are the result of lesions in the vagus nerve?

Answer 27

-ipsilateral paralysis of pharyngeal + laryngeal muscles

Question 28

what are signs of lesions in the vagus nerve?

Answer 28

- hoarseness - difficulty swallowing - difficulties in articulation

Question 29

what are the 4 components of the glossopharyngeal nerve?

Answer 29

1. motor (pharynx + larynx) 2. parasympathetic (salivary gland) 3. sensory (tonsil, pharynx, tongue) 4. taste (tongue)

Question 30

what reflex is often tested for the glossopharyngeal and vagus nerves? (9, 10)

Answer 30

gag reflex

Question 31

what is a sign of medial medullary syndrome?

Answer 31

- contralateral loss of position sense | - ipsilateral paralysis of half of tongue

Question 32

what is a cause for lateral medullary syndrome?

Answer 32

- occlusion of PICA | - occlusion of vertebral artery

Question 33

what is a sign of lateral medullary syndrome?

Answer 33

- ipsilateral loss of pain + temp over face - contralateral loss of pain + temp over body - loss of gag reflux

Question 34

what are the 2 components of the vestibulocochlear nerve?

Answer 34

- audition (cochlear) | - vestibular

Question 35

what are the 3 central pathways from the vestibular nuclei?

Answer 35

1. to cerebellum 2. to spinal cord 3. to medial longitudinal fasciculus

Question 36

what is a function of the vestibular pathway?

Answer 36

-maintain oculovestibular balance

Question 37

how is testing done for the vestibulocochlear nerve?

Answer 37

auditory/hearing test

Question 38

what are the 4 functional components of the facial nerve?

Answer 38

1. taste 2. parasympathetic (salivary) 3. sensory (small area behind ear) 4. motor (facial expression)

Question 39

which CNs are involved in the taste pathway?

Answer 39

1. facial nerve 2. glossopharyngeal 3. vagus

Question 40

what is the result of lesions involving the facial nerve?

Answer 40

-ipsilateral paralysis of facial muscles

Question 41

what are the two disorders associated with facial nerve lesions?

Answer 41

1. peripheral facial nerve (bell's palsy) | 2. central facial nerve (supranuclear palsy)

Question 42

what does the abducens nerve do?

Answer 42

- strictly motor nerve | - to one muscle in the eye

Question 43

what happens if the abducens nerve is lesioned?

Answer 43

-medial strabismus: ONly the affected eye does not abduct

Question 44

what are the 2 sensory pathways?

Answer 44

- ML | - Spinothalamic Tract

Question 45

what is the motor pathway?

Answer 45

corticospinal tract

Question 46

what is the substantia nigra?

Answer 46

part of basal ganglia

Question 47

what is the function of the trochlear nerve?

Answer 47

- when eye is turned medially, eye is depressed | - when eye is turned laterally, the superior oblique intorts the eye

Question 48

what is a sign of a trochlear nerve lesion?

Answer 48

double vision looking down stairs

Question 49

what are the 2 components of the oculomotor nerve?

Answer 49

1. motor: innervates eye lid, ocular muscles except LR, SO | 2. parasympathetic: preganglionic parasympahtetic innervasion

Question 50

what is oculomotor nerve palsy?

Answer 50

-squint -eyelid retracted -dilated pupil (all ipsilateral)