Lecture 4

Question 1

I Olfactory nerve: function

Answer 1

sensory - smells

Question 2

II Optic nerve: function

Answer 2

sensory - sees

Question 3

III Oculomotor nerve: function

Answer 3

motor/parasympathetic - moves eyes, constricts pupils, accommodates

Question 4

IV Trochlear nerve: function

Answer 4

motor - moves eyes

Question 5

V Trigeminal nerve: function

Answer 5

motor/sensory - Chews and face sensation

Question 6

VI Abducens nerve: function

Answer 6

motor - moves eyes

Question 7

VII Facial nerve: function

Answer 7

motor/sensory/parasympathetic - move the face, salivates, cries, taste

Question 8

VIII Vestibulocochlear nerve: function

Answer 8

sensory - hears, regulates balance

Question 9

IX Glossopharyngeal nerve: function

Answer 9

motor/sensory/parasympathetic - swallows, salivates, tongue and pharynx feeling, tastes

Question 10

X Vagus nerve: function

Answer 10

Motor/sensory/parasympathetic - swallows, lifts palate, talks, tastes, communications from thoracoabdominal viscera

Question 11

XI Accessory nerve: function

Answer 11

Motor - turns head, lifts shoulders (spinal part)

Cranial Part: control elevation fo larynx during swallowing (some fibers get mixed in with vagus, very small function)

Question 12

XII Hypoglossal nerve: function

Answer 12

Motor - moves tongue

Question 13

the oculomotor nerve innervates all eye muscles except for?

Answer 13

• superior oblique (trochlear)

- lateral rectus (abducens)

Question 14

lower motor lesion of oculomotor nerve can cause:

Answer 14

IPSILATERAL

• Lateral strabismus (pulled laterally because trochlear and abducens nerves still good)
• which causes diplopia (two eye dont match up = double vision)
• ptosis (eyelids drop)
• pupil dilated (parasympathetic control doesnt work)
• no accomodation

Question 15

lower motor lesion to trochlear nerve can cause

Answer 15

IPSILATERAL

• paralysis of superior oblique muscles (downward and lateraly)
• • results in medial and vertical strabismus, diplopia, and weakness of downward gaze

Question 16

lower motor lesion of abducen nerve can cause

Answer 16

IPSILATERAL

- paralysis of lateral rectus muscle –> medial stabismus, diplopia

Question 17

what bundle of fibers plays a huge role in coordinating the muscles of the eye (inhibiting one to move on way while activating the other).
What nuclei does this structure connect?

Answer 17

Medial Longitudinal fasciculus (MLF)
- connects the nuclei of CN III, IV, VI, VIII
(oculomotor, trochlear, abducens, vestibulocochlear)

Question 18

the medial longitudinal fasciculus (MLF) is involved in what reflexes?

Answer 18

visual and vestibulo-ocular reflexes

Question 19

where does the medial longitudinal fasciculus run to and from?

Answer 19

superior medulla (vestibular nuclei) to superior brainstem (oculomotor nuclei)

Question 20

LMN lesion of accessory nerve can result in ?

Answer 20

IPSILATERAL

• weakness of sternocleidomastoid - hard to turn head to side contralateral of lesion
• weakness of trapezius making it hard to elevate ipsilateral shoulder

Question 21

LMN lesion and upper motor lesion of hypoglossal nerve would cause what?

Answer 21

LMN: Ipsilateral paralysis of all tongue muscles –> deviation and atrophy to the affected side (strong side pushes it over)
UMN: affects only genioglossus muscle on contralateral side. tongue deviates to side opposite the lesion (to weak side)

Question 22

lesions to sensory paths of trigeminal nerve can lead to what?

Answer 22

• anesthesia and loss of sensation

- Trigeminal neuralgia: severe stabbing pain of the face

Question 23

Trigeminal neuralgia

Answer 23

caused from random activation of the trigeminal nerve, usually from vessels or arteries tangling it. leads to stabbing pains in face

Question 24

motor lesions of trigeminal nerve?

Answer 24

UMNL: little effect

LMNL result in paralysis or weakness on ipsilateral side

Question 25

lesion to the facial nerve could cause? (UMN/ LMN)

Answer 25

UMN: upper face movement not affected (bilateral innervation), lower face paralyzed or weak on contralateral side of lesion LMN: weakness or paralysis on ipsilateral side of face

Question 26

taste is considered a ___________ sensation

Answer 26

parasympathetic

Question 27

we have emotional control of the facial muscles via the ?

Answer 27

reticular formation

Question 28

what are the possible symptoms of bells palsy? | what cranial nerve lesion is this associated with?

Answer 28

- facial nerve - droopy eyelid, dry eye, or excessive tears - facial paralysis, twitching, or weakness - drooping corner of mouth, dry mouth, impaired taste - -> all on ONE SIDE

Question 29

what 2 cranial nerves are involved in salivation?

Answer 29

glossopharyngeal ad facial nerve

Question 30

Lesion to glossopharyngeal nerve may lead to?

Answer 30

- loss of sensation from the pharynx - loss of gag reflex - loss of taste from posterior third of tongue

Question 31

damage of soley the glossopharyngeal nerve is rare, it also usually includes what nerve?

Answer 31

vagus nerve

Question 32

Lesion of the vagus nerve can result in?

Answer 32

UMNL: little effect LMNL: - weakness of the ipsilateral pharyngeal and laryngeal muscles - see arch of soft palate drooping on ipsilateral side - uvula deviates to the contralateral side - hoarse voice (dysphonia) - difficulty swallowing (dysphagia Parasympathetic: - loss of cough reflex - loss of gag reflex - irregular rapid heart beat (tachycardia) - difficulty breathing (dyspnea)

Question 33

some branches of the olfactory nerve goes where?

Answer 33

the amygdala, | smell has a strong emotional association

Question 34

lesion to olfactory nerve can result in ?

Answer 34

- loss of smell = anosmia | ipsilateral (test each nostril)

Question 35

damage to what part of the olfactory cortex can cause olfactory hallucinations?

Answer 35

inferior temporal lobe

Question 36

two injuries that can cause anosmia

Answer 36

- Skull fracture in the area of the anterior cranial fossa can cause tearing of fibers (olfactory) - Frontal lobe tumours can cause ipsilateral anosmia

Question 37

why do you test pupils for brain injury?

Answer 37

- dont have to be conscious for reflex - oculomotor nerve will be pressed on if you have swelling in the brain so you can check how much swelling by if the pupillary light reflex is present or not

Question 38

the oculomotor nucleus also recieves axons from what two structures?

Answer 38

- superior colliculus for visual reflexes | - medial longitudinal fasiculus which connects nuclei of 3, 4, 6, 8 (oculomotor, trochlear, abducens, vestibulocochlear)

Question 39

blindness in one eye

Answer 39

monocular blindness

Question 40

blindness of temporal visual field of both eyes

Answer 40

bitemporal hemianopia

Question 41

blindness of nasal field of one eye

Answer 41

right/ left nasal hemianopia

Question 42

blindness of a full visual field (both eyes)

Answer 42

homonyous hemianopia