Cranial Nerves

Question 1

Afferent portions of the Cranial Nerves originate in the

Answer 1

Ganglia outside of the brainstem

Question 2

Efferent portions of the Cranial Nerves have their cell bodies in the….

Answer 2

Nuclei in the brainstem

Question 3

Cranial Nerves are innervated by the corticobulbar tracts: True or False

Answer 3

True

Question 4

Trigeminal Nerve or CN V has what kind of innervation?

A.) Sensory Nerve

B.) Motor Nerve

C.) Mixed Nerve

D.) None of the above

Answer 4

C.)Mixed Nerve - has both motor and sensory functions

Question 5

The motor nerve nuclei of CN V is called

Answer 5

Trigeminal Motor Nuclei

Question 6

The trigeminal motor nuclei is located

Answer 6

In the Pons

Question 7

The sensory nucleus of CN V is called

Answer 7

Trigeminal Sensory Nucleus

Question 8

The motor portion of CN V innervates muscles of the:

Answer 8

Jaw (Opening: Masseter, Temporalis, Medial Pterygoid
Closing: Lateral Pterygoid, Anterior Belly of Digastric and Mylohyoid)

Velopharyngeal (*Tensor Veli Palatini)*
Tympanic Membrane (*Tensor Tympani*)

Question 9

The sensory portion of CN V is divided into how many branches?

A.) 4 Branches

B.) 2 Branches

C.) 3 Branches

D.) 6 Branches

Answer 9

C.) 3 Branches - Opthalmic, Maxiallary, and Mandibular

Question 10

The Opthalmic Nerve (Branch) of CN V innervates:

Answer 10

Sensation of forehead, eyes, and nose

Question 11

The Maxillary Nerve (Branche) of CN V innervates:

Answer 11

upper lip mucosa, maxilla, upper teeth, cheeks, palate and maxillary sinus.

Question 12

The Mandibular Nerve (Branch) of CN V innervates:

Answer 12

anterior 2/3 of tongue, mandible, lower teeth, lower lip, part of the cheek, and part of the external ear

Question 13

The functions of the Trigeminal Nerve (CN V) are:

A.) Mastication and Articulation

B.) Hyolaryngeal elevation

C.) Tensing/closing of the soft palate

D.) Sensation to face, teeth, gums and anterior 2/3 of tongue

E.) All of the above

Answer 13

E.) All of the above

Question 14

Motor Testing -

Lower Motor Neuron lesion in CN V will result in :

Answer 14

Reduced bulk and firmness in masseter muscles

Question 15

Motor Testing:

If there is weakness of the lateral pterygoid muscle:

Answer 15

client will have difficulty moving jaw in opposite direction.

i.e. if left branch of CN V is damaged and left lateral pterygoid is involved, the client will have difficulty moving jaw to the right.

Question 16

Unilateral UMN damage of CN V results in significant motor deficits : True or False?

Answer 16

False - no significant motor deficits due to Billateral innervation.

Question 17

Unilateral LMN damage of CN V results in the mandible being deviated towards the side of paralysis/paresis during opening: True or False

Answer 17

True

Question 18

Bilaterral UMN damage to CN V does not result in hypertonia, slow movements, restricted jaw opening/closing, and reduced hyolaryngeal elevation: True or False

Answer 18

False - Bilaterral UMN damage to CN V DOES result in hypotonia, slow movements, restricted jaw opening/closing, and reduced hyolaryngeal innervation

Question 19

Bilaterral LMN damage does result in hypotonia, impaired jaw opening/closing, and impaired hyolaryngeal elevation: True or False

Answer 19

True

Question 20

Sensory Testing of CN V

Lesions that are distal to the Trigeminal Ganglion results in sensory loss or parathesias to multiple divisions:

True or False

Answer 20

False - Lesions that are distal to the Trigeminal Ganglion results in sensory loss or parathesias in single division

Question 21

Sensory Testing of CN V

Lesions that are proximal to the trigeminal ganglion will result in sensory dysfunction over whole contralateral face: True or False

Answer 21

False - lesions that are proximal to the trigeminal ganglion will result in sensory dysfunction over whole ipsilateral face

Question 22

CN VII - Facial Nerve has what kinds innervation?

A.) Motor only

B.) Sensory only

C.) Mixed Nerves

D.) None of the above

Answer 22

C. Mixed - both motor and sensory

Question 23

CN VII

Motor pathways begin in the facial motor nucleus of the:

Answer 23

Pons

Question 24

CN VII

Sensory pathways have their cell bodies in the:

Answer 24

Geniculate Ganglion (facial canal of temporal bone)

Side Note: Terminate in tractus solitarus (taste) and spinal nucleus of trigeminal nerve (touch)

Question 25

CN VII Motor branches of CN VII innervates:

Answer 25

muscles of facial expression platysma, stylohyoid, stapedius, posterior belly of digastric, lacrimal, submandibular, and sublingual glands

Question 26

CN VII Sensory branches innervates:

Answer 26

taste for anterior 2/3 of tongue, floor of mouth, soft and hard palate, and external ear/auditory meatus

Question 27

CN VII - Functions The functions of CN VII are: A.) movement of facial expression B.) Supports Hyolaryngeal Elevation C.) Saliva and Tear Production D.) Taste (ant. 2/3 of Tongue) E.) All of the above

Answer 27

E.) All of the above

Question 28

CN VII - Motor Testing When doing CN VII Motor Testing you are looking for: A.) Weakness and asymmetry B.) Weakness and symmetry C.) Strength and asymmetry D.) Strength and symmetry E.) None of the above

Answer 28

A.) Weakness and asymmetry Side Note: looking for nasolabial fold, smooth forehead, lower face droop, ability to wrinkley forehead, close eyes tightly, ability to spread lips, keep lips compressed against resistance, etc.

Question 29

CN VII Unilateral UMN Damage gives: A.) Ipsilateral lower face weakness B.) Contralateral lower face weakness C.) Ipsilateral upper face weakness D.) Contralateral upper face weakness

Answer 29

A.) Ipsilateral lower face weakness \*no upper face weakness because it is bilaterally innervated \*may see normal spontaneous smile that is emotionally triggered

Question 30

CN VII Bilaterral UMN Damage causes spastic paralysis of the whole face: True or False

Answer 30

True

Question 31

CN VII Unilateral LMN Damage does not cause ipsilesional facial weakness: True or False

Answer 31

False - does cause ipsilesional facial weakness \*unless specific branch of CN VII is damaged, weakness will occur in both the upper and lower facial muscles

Question 32

CN VII Damage Bilateral LMN Damage causes: A.) Contralateral facial weakness B.) Ipsilateral facial weakness C.) Bilateral facial weakness D.) Unilateral facial weakness

Answer 32

C - Bilaterall facial weakness \*flaccid paralysis

Question 33

CN VII Facial Nerve Sensory Testing You do taste testing to check for sensory testing of CN VII: True or False

Answer 33

True

Question 34

CN IX Glossopharyngeal CN IX emerges from the:

Answer 34

Medulla \*motor portions originate in the nucleus ambiguus in medulla \*sensory components are processed in the nucleus solitarus in the medulla

Question 35

CN IX Innervation The Glossopharyngeal nerve innervates:

Answer 35

Stylopharyngeus muscle \*general sensation for the post 1/3 of the tongue, soft palate, fauces, tonsils and adenoids \*taste from the post 1/3 of the tongue

Question 36

Motor portion of CN IX innervates the stylopharyngeus muscles which assists in:

Answer 36

elevation of the larynx and pharynx during swallow

Question 37

Sensory innervation of CN IX plays an important role in triggering the:

Answer 37

Pharyngeal stage of swallowing \*sensory component of the gag reflex

Question 38

CN IX Motor Testing It is easy to test the motor portion of CN IX in isolation from CN X: True or False

Answer 38

False - It is **difficult** to test the motor portion of CN IX in isolation from CN X

Question 39

CN IX Sensory Testing You test this in order to check for sensory functions of CN IX:

Answer 39

Test the phrayngeal gag reflex \*absence of a pharyngeal gag response may indicate damage to either the sensory component (CN IX) or motor component (CN X) \*If patient reports sensing stroking back wall but no gag reflex, this may indicate isolated impairment of motor component

Question 40

CN X - Vagus Nerve Motor portions of CN X originate in the:

Answer 40

nucleus ambiguuus in the Medulla

Question 41

CN X - Vagus Nerve Sensory pathways have their cell bodies in _____ and terminate in the ______ in the medulla.

Answer 41

the nucleus ambiguus, nucleus solitarus

Question 42

CN X has two branches the _____ branch and _____ branch

Answer 42

laryngeal, pharyngeal \*laryngeal branch is split into: recurrent and superior laryngeal nerve \*the superior laryngeal is broken down even further: internal laryngeal nerve and external laryngeal nerve

Question 43

The Recurrent Laryngeal Nerve innervates:

Answer 43

the intrinsic laryngeal muscles except for the cricothyroid \*left branch - descends and loops around aorta before returning to larynx \*right branch - descends and loops around subclavian artery before returning to larynx

Question 44

The Recurrent Laryngeal Nerve is also responsible for:

Answer 44

sensation to the true vocal folds and the area below the vocal folds

Question 45

The Superior Laryngeal Nerve's Internal Branch provides sensory innervation to the:

Answer 45

epiglottis, base of tongue, aryeppiglottal folds, and the inner surfaces of the larynx

Question 46

The Superior Laryngeal Nerve's External Branch innervates the:

Answer 46

Cricothyroid muscle

Question 47

The pharyngeal branch of CN X innervates muscles of the ______ and \_\_\_\_\_\_

Answer 47

pharynx and soft palate (pharynx - pharyngeal constrictors) (soft palate - velopharyngeal closure)

Question 48

CN X Function The motor function of CN X is involved in \_\_\_\_\_\_\_, \_\_\_\_\_\_\_, and \_\_\_\_\_\_\_\_\_.

Answer 48

voice production, velopharyngeal closure, and swallowing (voice production via the recurrent laryngeal nerves and assistance from superior laryngeal nerves) (velopharyngeal closure maintains proper resonance and intra-oral pressure)

Question 49

Sensory innervation of CN X plays an important role in the process of:

Answer 49

swallowing (base of tongue plays a role in pharyngeal phase of swallow) (above and below vocal folds is responsible for triggering cough reflex) (rest of pharynx allows for detection of food/liquid residue after swallow)

Question 50

CN X Motor Testing You observe the _____ at rest to look for asymmetry

Answer 50

palate \*observe the palatal movement during production of "ah" \*palatal arch hanging low on one side suggests weakness

Question 51

CN X Motor Testing II You also check for these two things: _____ and \_\_\_\_\_\_

Answer 51

vocal quality and glottal coup/voluntary cough \*paralysis or paresis involving the vocal folds will manifest as vocal breathiness and hoarseness \*in cases of vocal weakness, both the cough and glottal coup will have a blurred attack

Question 52

CN X Sensory Testing Specific testing of the sensory component of CN X is done during a neurological examination or oral-motor exam: True or False

Answer 52

False - specific testing is **not** done during a neurological examination or oral-motor exam

Question 53

Unilateral UMN damage to CN X does result in overt symptoms: True or False

Answer 53

False- does not result in over symptoms \*remember there is bilaterral innervation of CN X

Question 54

Bilateral UMN damage causes _____ and ______ in vocal quality.

Answer 54

hypernasality and strained-strangled

Question 55

Unilateral LMN damage to CN X will result in ipsilateral signs of _____ and \_\_\_\_

Answer 55

palatal weakness and vocal fold paresis/paralysis

Question 56

CN XI - Spinal Accessory receives what kind of innervation? A.) Sensory only B.) Motor only C.) Mixed D.) None of the above

Answer 56

B - Motor only \*consists of a cranial and spinal root \*cranial root originates in the nucleus ambiguus \*spinal root originates at the spinal nucleus of the upper spinal cord

Question 57

Cranial roots of CN XI joins the vagus nerve (CN X) to innervate the \_\_\_\_\_\_\_\_.

Answer 57

palatal muscles

Question 58

The spinal roots of CN XI innervates the ____ and ____ msucles.

Answer 58

trapezius and sternocleidomastoid \*helps turn, tilt, and thrust head forward

Question 59

CN XII - Hypoglossal Nerve CN XII receives what kind of innervation? A.) Sensory only B.) Mixed C.) Motor only D.) None of the above

Answer 59

C - Motor only

Question 60

The hypoglossal nerve (CN XII) originates in the:

Answer 60

medulla \*receives bilaterral innervation except for those neurons that innervate the genioglossus muscle (only contralateral)

Question 61

Hypoglossal nerve (CN XII) innervates muscles of the:

Answer 61

tongue both intrinsic and extrinsic muscles \*intrinsic muscles move and change shape of tongue to aid in chewing, swallowing and speech \*3 **extrinsic tongue muscles** - genioglossus: protrudes and depresses - hyoglossus: depresses - styloglossus: retracts and elevates

Question 62

The functions of the hypoglossal nerve (CN XII) are:

Answer 62

moving the muscles of the tongue for articulation, oral stage of swallowing (moving bolus from oral cavity to pharynx), and pharyngeal stage of swallowing (innervates geniohyoid which elevates the larynx)

Question 63

Motor Testing for CN XII You look at the tongue at rest for signs of:

Answer 63

atrophy, fasciculations, and tremor or random movements

Question 64

Motor Testing for CN XII Part II You also check for the tongue's _____ and \_\_\_\_\_\_.

Answer 64

strength and range of motion \*look for range of motion and symmetry (tongue will deviate towards weak side) \*if patient pushes weakly against left cheek, then the weakness is on the right side

Question 65

Motor Testing for CN XII Part III We also check to see if the tongue has _____ and \_\_\_\_\_.

Answer 65

speed and accuracy \*check for slow or abnormally discoordinated tongue movements \*discoordinated/disorganized tongue movements can be seen in presence of damage to cerebellum or motor planning portion of cortex

Question 66

Unilateral UMN damage to CN XII results in _____ weakness:

Answer 66

contralateral \*deviation of tongue to one side on protrusion can result from UMN or LMN damage

Question 67

Unilateral LMN damage to CN XII results in ____ weakness:

Answer 67

ipsilateral \*to determine if UMN or LMN damage: check for presence of atrophy on one side and/or fasciculation (LMN) \*If patient is known to have had cortical lesion or present with linguistic/cognitive impairments consistent with a left or right hemisphere damage, then suggests UMN.

Question 68

Bilateral UMN or LMN damage to CN XII will result in:

Answer 68

weakness on both sides \*Bilateral UMN damage presents with reduced range of motion and slow movements