Slpa 853 - Neurology - Cranial Nerves

Front 1

True or false: Cranial nerves are inside the CNS.

Back 1

False: outside

Front 2

Where is the origin of the cranial nerves?

Back 2

brainstem (in CNS, but axons are outside)

Front 3

How many cranial nerves are there?

Back 3

12

Front 4

UMN are located where AND carry info where?

Back 4

-located in CNS (never leave it)
-carry info into brain (stop at brainstem)

Front 5

Where do LMN originate at AND what do they innervate?

Back 5

-originate at the brainstem
-innervate muscle

Front 6

What is another name for LMN?

Back 6

alpha motoneurons

Front 7

What are the 3 classes of neurons AND where are they located?

Back 7

-multipolar (motor and interneurons)
-bipolar (only found in ear and eye)
-unipolar (all sensory neurons are unipolar)

Front 8

True or false: Alpha motoneurons (LMN) are large and can be up to a meter long in humans.

Back 8

True

Front 9

Are alpha motoneurons myelinated?

Back 9

Yes

Front 10

What do alpha motoneurons terminate as? They are always what? AND what do they release?

Back 10

-terminate as motor endplate
-always excitatory (cause muscle to contract)
-release only Acetylocholine (Ach) (NT that causes the muscle to contract)

Front 11

What forms connections between muscles and CNS (motor cortex)?

Back 11

lower motor neurons

Front 12

True or false: All motor Cranial Nerves are lower motor neurons.

Back 12

True

Front 13

What is the final common pathway?

Back 13

alpha motoneurons and their axons are the only connection between the CNS and muscle

Front 14

Where do most of the cranial nerves originate?

Back 14

in the brainstem (10 of the 12 do)

Front 15

What do the motor nuclei receive impulses from?

Back 15

cortex through the corticobulbar tract

Front 16

Where are motor nuclei located?

Back 16

in the brainstem

Front 17

Where are the cell bodies for afferent connections of cranial nerves located?

Back 17

-outside of the brainstem in ganglia
-in a sensory organ such as the ear or the eye

Front 18

Name the cranial nerves.

Back 18

I. Olfactory
II. Optic
III. Oculomotor
IV. Trochlear
V. Trigeminal
VI. Abducens
VII. Facial
VIII. Vestibulocochlear
IX. Glossopharyngeal
X. Vagus
XI. Accessory
XII. Hypoglossal

Front 19

Which 2 cranial nerves do not originate in the brainstem?

Back 19

I. Olfactory
II. Optic

Front 20

Which is the largest cranial nerve?

Back 20

V. Trigeminal

Front 21

What are the major functions of cranial nerve III?

Back 21

-occulomotor
-eyelid and eyeball movement
-maintaining an open eyelid, precise movement of the eyes for visual tracking and fixation on an object, constriction of the pupil, adjustment of the pupil to light
-motor nerve for vision

Front 22

What is the major function of cranial nerve IV?

Back 22

-trochlear
-motor nerve for vision
-innervates superior oblique turns eye downward and laterally

Front 23

What is the major function of cranial nerve VI?

Back 23

-Abducens
-motor nerve for vision
-turns eye laterally

Front 24

What type of nerve is cranial nerve V?

Back 24

mixed (anterior- motor, posterior- sensory)

Front 25

What are the major functions of cranial nerve V?

Back 25

-sensory for face and head
-motor for muscles of mastication and speech

Front 26

What are the 3 divisions of cranial nerve V?

Back 26

(trigeminal)
-opthalamic (sensory)
-maxillary (sensory)
-mandibular (mixed)

Front 27

What type of innervation does cranial nerve V receive from the motor cortex?

Back 27

(trigeminal)
receives bilateral innervation

Front 28

True or false: All cranial nerves receive bilateral innervation.

Back 28

False - Hypoglossal?

Front 29

What are the muscles of mastication that cranial nerve V has motor pathways to?

Back 29

-masseter (elevates jaw)
-temporalis (elevates jaw)
-anterior belly of the digastric (lowers jaw)
-medial and lateral pterygoid (protrusion of jaw)
-mylohyoid (lowers jaw and elevates tongue and floor of oral cavity)
-tensor veli palatini (tenses soft palate)
-tensor tympani (tenses tympanic membrane)

Front 30

Where does cranial nerve V provide sensation (touch and pressure) to?

Back 30

-face and scalp
-mucous membrane in oral cavity
-anterior 2/3 of tongue, and teeth

Front 31

Sensory neurons have cell bodies in the trigeminal ganglion and project centrally to the....

Back 31

-mesencephalic nucleus
-principle sensory nucleus (pontine trigeminal nucleus)
-spinal nucleus (nucleus of spinal tract)

Front 32

Injury to sensory branches of the trigeminal nerve will result in?

Back 32

numbness in face (fractures of facial bones may sever sensory branches)

Front 33

What is Trigeminal neuralgia?

Back 33

-aka tic douloureux - means painful tic
-a facial pain syndrome
-severe pain of unknown origin
-onset of pain is rapid in response to only mild stimuli
-usually develops in individuals over 50 years old and the most common facial pain syndrome in this age group
-incidence of 4/100,000

Front 34

What would happen if there were an UMN lesion of the trigeminal nerve?

Back 34

slight spasticity, but ability to chew only mildly affected because of bilateral innervation

Front 35

What would happen if there were an LMN lesion of the trigeminal nerve?

Back 35

-mandible will deviate toward the affected side due to unopposed pull of lateral pterygoid
-ipsilateral flaccidity or paralysis and atrophy

Front 36

Is the facial nerve motor, sensory, or mixed?

Back 36

mixed

Front 37

What type of innervation does the facial nerve have?

Back 37

bilateral and contralateral (exception to the rule)

Front 38

What 3 nuclei of the facial nerve originate from the lower pons? AND what do they innervate?

Back 38

-motor (face)
-nucleus of the tractus solitarius
-parasympathetic (superior salvitory nucleus)

Front 39

True or false: The tractus solitarius is shared by other cranial nerves.

Back 39

True

Front 40

What does the parasympathetic nuclei of the facial nerve supply?

Back 40

glands

Front 41

What does the tractus solitarius of the facial nerve provide?

Back 41

taste

Front 42

What are the motor pathways of CN VII?

Back 42

-efferent fibers from the cortex project via the corticobulbar tract to the ipsilateral and contralateral motor nuclei in the pons

Front 43

Explain the bilateral and contralateral features of CN VII.

Back 43

fibers that project to:
-forehead are bilateral
-lower facial muscles are contralateral

Front 44

If CNs VI and VII are not functioning, where is the lesion?

Back 44

within the pons

Front 45

If CNs VII and VIII are not functioning, where is the lesion?

Back 45

in the region of internal acoustic meatus

Front 46

What function does CN VII provide to the tongue?

Back 46

taste for the anterior 2/3 portion

Front 47

What CNs provide taste to the nucleus solitarius?

Back 47

-facial
-vagus
-glossopharyngeal

Front 48

Where does the super salivatory nucleus receive input from?

Back 48

hypothalamus

Front 49

For salivation, food stimulates tactile, pressure, and taste receptors, which transmit signals where?

Back 49

to the salivatory nuclei in the medulla and pons

Front 50

What stimulates salivation?

Back 50

-tactile, pressure, and taste receptors
-odor
-sight
-thought of food

Front 51

What does an UMN lesion of CN VII cause?

Back 51

loss of voluntary control of only lower muscles of facial expression contralateral innervation

Front 52

What does a LMN lesion of CN VII cause?

Back 52

all muscles supplied by nerve are paralyzed ipsilaterally

Front 53

Describe Bells Palsy.

Back 53

-LMN paralysis of muscle of one side of face
-no known etiology (thought to be viral or immune deficiency)
-usually resolves spontaneously in 3-4 weeks)

Front 54

Is CN VIII sensory, motor, or mixed? AND what type of innervation does it supply?

Back 54

-sensory (hearing and balance)
-bilateral

Front 55

Is CN IX sensory, motor, or mixed? AND what type of innervation does it supply?

Back 55

-mixed
-bilateral

Front 56

Where does the motor branch of the glossopharyngeal CN pass thru? AND what is the function of this motor branch?

Back 56

-nucleus ambiguous:
-- only to stylopharygeus (elevates larynx and pharynx; dialates pharynx to permit the passage of large bolus)

Front 57

Where does the sensory branch of CN IX pass thru?

Back 57

nucleus solitarious (specialized nucleus for taste)

Front 58

What does the sensory branch of CN IX do?

Back 58

-provides sensation to palate, pharynx, and tongue
-touch and taste from posterior 1/3 of tongue
-afferent component of gag relex (CN X is the efferent part)

Front 59

What does damage to IX CN cause?

Back 59

absence of gag reflex

Front 60

What are possible causes of a LMN lesion?

Back 60

-brain stem stroke
-spinal injury
-surgery
-viral infection on cranial nerve (e.g., Bells Palsy)
-bacterial infection

Front 61

If the tongue deviates to the left due to an UMN lesion in the facial CN, which motor strip is affected?

Back 61

right side

Front 62

Is Vagus CN ("The Wanderer") sensory, motor, or mixed? AND what type of innervation does it provide?

Back 62

-mixed
-bilateral innervation

Front 63

What 3 nuclei located in the medulla are associated with CN X? AND tell whether they are motor or sensory.

Back 63

-nucleus ambiguus (motor)
-dorsal nucleus (motor)
-nucleus solitarius (sensory)

Front 64

What 3 branches are there of the nucleus ambiguus (a nuclei of the vagus nerve)?

Back 64

-pharyngeal branch
-laryngeal branch
-superior laryngeal branch

Front 65

Describe the dorsal nucleus branch of CN X.

Back 65

-motor
-parasympathetic: involuntary muscles of bronchi, esophagus, heart, stomach, small intestine and most of large intestine

Front 66

Describe the nucleus solitarius branch of CN X.

Back 66

mediates larynx, pharynx, thorax, and abdomen

Front 67

Describe how the nucleus ambiguus relates to CN X.

Back 67

-central connections: descending input is bilateral from corticobulbar fibers

Front 68

What are the 3 major motor branches of the nucleus ambiguus for the Vagus CN?

Back 68

-pharyngeal
-superior laryngeal nerve
-recurrent laryngeal nerve

Front 69

What are the 2 branches of the superior laryngeal nerve branch of the nucleus ambiguus of the vagus CN? AND tell whether they are sensory or motor.

Back 69

-internal branch: sensory
-external branch: motor (innervates one muscle--cricothyroid-->pitch)

Front 70

Describe the pharyngeal branch of the nucleus ambiguus of the vagus CN.

Back 70

innervates:
-all muscles of the pharynx except stylopharyngeus (CN IX)
-all muscles of the palate except tensor veli palatini (CN V3)

Front 71

Describe the recurrent laryngeal nerve branch of the nucleus ambiguus of the vagus CN.

Back 71

-motor to intrinsic muscles of larynx
-sensory to regions below vocal folds

Front 72

What are the 2 sensory pathways of CN X?

Back 72

-internal superior laryngeal
-recurrent laryngeal nerve

Front 73

What areas does CN X provide sensory to?

Back 73

-larynx
-pharynx
-thorax
-abdomen

Front 74

Describe the internal superior laryngeal sensory branch of CN X.

Back 74

-general sensation (pain, touch, temp): mucosa in pharynx; laryngeal region above vocal fold
-sensory fibers project to the nucleus solitarius innervating taste buds overlying epiglottis

Front 75

Describe the recurrent laryngeal nerve sensory branch of CN X.

Back 75

general sensation (pain, touch, temp): laryngeal region at vocal folds and below