Ch. 25 Facial and Abducens Nerves

Question 1

The seventh cranial nerve is called the facial nerve because it contains the axons of _________ _________ ___________ for the muscles of facial expression.

Answer 1

lower motor neurons

Question 2

VIII and VII emerge from the _________________ at the boundary between the pons and the medulla

Answer 2

brainstem

Question 3

The motor nucleus of the facial nerve straddles the boundary between the _____ and the __________.

Answer 3

pons

medulla

Question 4

The motor nucleus of the facial nerve is an oval mass of ________ matter medial and inferior to the spinal tract of the trigeminal nerve.

Answer 4

gray

Question 5

Since the overwhelming majority of fibers in the facial nerve are branchial motor the _____________ __________ _____________ of the facial nerve is usually simply called the facial nucleus.

Answer 5

branchial motor nucleus

Question 6

The motor fibers leave the medial side of the _________ nucleus, curve dorsad toward the fourth ventricle, run laterad in the floor of the fourth ventricle, and run ventrad between the facial nucleus and the spinal tract of the trigeminal nerve.

Answer 6

facial

Question 7

Running dorsal from the medial side of the facial nucleus and ventrad on the lateral side of the facial nucleus the __________ fibers of the ___________ nerve form a loop at the lowest level of the pons.

Answer 7

motor

facial

Question 8

The middle portion of the loop, in the floor of the _________ ____________, is called the internal genu of the facial nerve.

Answer 8

fourth ventricle

Question 9

The internal genu of the facial nerve contains only _________ fibers.

Answer 9

motor

Question 10

The ___________ ________ of the facial nerve is in the floor of the fourth ventricle.

Answer 10

internal genu

Question 11

Beyond its internal genu the ________ root of the facial nerve continues laterad and ventrad between the facial nucleus and the spinal tract of V.

Answer 11

motor

Question 12

The motor root of the facial nerve passes between the __________ ________ of ___ and the ________ ___________ before leaving the brainstem.

Answer 12

motor nucleus V

facial nucleus

Question 13

The facial nerve leaves the brainstem through the lowest part of the middle cerebellar peduncle just above the foramen of ___________.

Answer 13

Luschka

Question 14

Since the _________________________ nerve leaves the brainstem through the foramen of Luschka, and the _________ nerve leaves just above the foramen of Luschka, the _______________________ and _________ nerves are close neighbors.

Answer 14

vestibulocochlear
facial
vestibulocochlear
facial

Question 15

A lesion of the root of the _________________________ nerve is liable to involve the _________ nerve as well.

Answer 15

vestibulocochlear

facial

Question 16

The region around the roots of the facial and vestibulocochlear nerves is called the cerebellopontine angle because it is a triangle bounded by the medulla, the posterior lobe of the _________________, and the ________.

Answer 16

cerebellum

pons

Question 17

The facial nerve contains many somatic __________ fibers but hardly any somatic sensory fibers

Answer 17

motor

Question 18

As is always true for sacral and cranial nerves, the facial nerve contains no preganglionic _______________ fibers.

Answer 18

sympathetic

Question 19

Like several other cranial nerves, the facial nerve does contain preganglionic __________________ fibers.

Answer 19

parasympathetic

Question 20

The preganglionic _____________________ fibers in the facial nerve originate in the superior salivatory nucleus of the pons and end in the submandibular ganglion

Answer 20

parasympathetic

Question 21

The submandibular ganglion receives preganglionic parasympathetic fibers from the _____________ _______________ __________ via the __________ nerve.

Answer 21

superior salivatory nucleus

facial

Question 22

The submandibular ganglion supplies _______________ ___________________ fibers to the submandibular and sublingual _____________ glands.

Answer 22

postganglionic parasympathetic

salivary

Question 23

The (parasympathetic) visceral motor nucleus of the facial nerve is called the ___________

Answer 23

superior salivatory nucleus

Question 24

Despite its name, the superior salivatory nucleus provides ______________ ___________________ fibers to the sphenopalatine ganglion which provides ________________ _____________________ fibers to the lacrimal gland. (“Sphenopalatine ganglion” is slowly replacing “pterygopalatine ganglion.”)

Answer 24

preganglionic parasympathetic

postganglionic parasympathetic

Question 25

The lacrimal gland gets postganglionic parasympathetic innervation from the ___________________ ganglion which gets its preganglionic innervation from the ____________ _______________ _________.

Answer 25

sphenopalatine | superior salivatory nucleus

Question 26

Thus the cornea depends on the ____________ ______________ nucleus, the ________ nerve and the _____________________ ganglion to keep it moist and transparent.

Answer 26

superior salivatory nucleus facial sphenopalatine

Question 27

The superior salivatory nucleus is in the lower pons just above the __________ ______________ nucleus in the _____________.

Answer 27

inferior salivatory | medulla

Question 28

The motor part of the facial nerve passes through the superior salivatory nucleus in the lower ______ without receiving fibers from it.

Answer 28

pons

Question 29

The superior salivatory nucleus lies in the path of the _________ _________ of the _________ nerve dorsal to the facial nucleus and ventral to the medial vestibular nucleus.

Answer 29

motor root | facial

Question 30

The superior salivatory nucleus is ____________ to the inferior salivatory nucleus, ________ to the facial nucleus, and __________ to the internal genu of the facial nerve.

Answer 30

superior dorsal lateral

Question 31

The superior salivatory nucleus and inferior salivatory nucleus are ____________ motor nuclei.

Answer 31

visceral

Question 32

The facial nerve has 2 motor nuclei of 2 different kinds, __________ and ___________ , and the special sensory nucleus for taste.

Answer 32

somatic, visceral

Question 33

The only sensory fibers in the facial nerve are those carrying the sense of ________.

Answer 33

taste

Question 34

The facial ganglion contains the primary sensory neurons for _________ in the anterior 2/3 of the tongue.

Answer 34

taste

Question 35

The primary sensory neurons for taste in the posterior 1/3 of the tongue are in the _____________ ________________________ ganglion, and the primary sensory neurons for taste in the anterior 2/3 of the tongue are in the _________ ganglion.

Answer 35

inferior glossopharyngeal | facial

Question 36

Because bitterness receptors are concentrated on the back of the tongue, most of the taste information in the ______________________ nerve is bitter.

Answer 36

glossopharyngeal

Question 37

Because sweetness receptors are concentrated on the tip of the tongue, most sweetness information travels in the _________ ________.

Answer 37

facial nerve

Question 38

The superior third of the ___________ _______________ receives taste sensations from the back of the tongue from the __________ ________________________ ganglion and taste sensations from the middle and front of the tongue from the _________ ganglion.

Answer 38

solitary nucleus inferior glossopharyngeal facial

Question 39

The central processes of primary sensory neurons for taste synapse in the _____________ _________ of the ___________ _______________ which is sometimes called the gustatory nucleus

Answer 39

superior third | solitary nucleus

Question 40

The gustatory nucleus is the ____________ ________ ___ _____ __________ __________________.

Answer 40

superior third of the solitary nucleus

Question 41

The taste fibers in the facial nerve travel with the parasympathetic fibers dorsolateral to the facial _________ fibers in the pons.

Answer 41

motor

Question 42

The facial and vestibulocochlear nerves leave the brainstem in the _________________________ ________.

Answer 42

cerebellopontine angle

Question 43

The motor and parasympathetic roots of the facial nerve are separate as they emerge from the brainstem in the _______________________ ______.

Answer 43

cerebellopontine angle

Question 44

The parasympathetic root of the facial nerve is called the nervus intermedius because it lies between the motor root of the facial nerve and the root of the _____________________________

Answer 44

vestibulocochlear

Question 45

The parasympathetic and taste fibers of the facial nerve leave the brainstem together as the __________ _______________.

Answer 45

nervus intermedius

Question 46

The nervus intermedius gets its name because it is _______________ between the motor root of the facial nerve and the roots of the vestibulocochlear nerve.

Answer 46

intermediate

Question 47

The nervus intermedius joins the motor root of the facial nerve shortly after they emerge from the brainstem in the _____________________ ________.

Answer 47

cerebellopontine angle

Question 48

Just after its motor root is joined by the _________ ___________________, the facial nerve enters the facial canal through the internal acoustic meatus

Answer 48

nervus intermedius

Question 49

The facial nerve passes through the petrous part of the temporal bone inside the ________ ________.

Answer 49

facial canal

Question 50

The facial nerve and the vestibular and cochlear divisions of the vestibulocochlear nerve go their separate ways inside the ____________ part of the _____________ bone

Answer 50

petrous | temporal

Question 51

The internal acoustic meatus is shared by the _________ _________ and the ____________________ ________, but the facial canal contains only the facial nerve and its sensory ganglion.

Answer 51

facial nerve | vestibulocochlear nerve

Question 52

The bend of the motor root of the facial nerve in the pons is called the ____________ _________ of the ________ ________.

Answer 52

internal genu | facial nerve

Question 53

The bend of the facial nerve inside the petrous part of the temporal bone is called the external ______ of the _________ __________.

Answer 53

genu facial nerve

Question 54

The sensory ganglion of the facial nerve is called the geniculate ganglion because it is located at the _____________ ________ of the _________ _________ inside the facial canal in the temporal bone.

Answer 54

external genu | facial nerve

Question 55

The peripheral processes of the neurons in the geniculate ganglion reach the taste buds on the _____________ _____ of the ____________ by passing through the middle ear and exiting the skull through the tympanic fissure.

Answer 55

anterior third tongue

Question 56

The taste fibers that leave the skull through the _____________ __________ are called the chorda tympani.

Answer 56

tympanic fissure

Question 57

The branch of the facial nerve that supplies taste fibers to the anterior 2/3 of the tongue is called the _________ ______________.

Answer 57

chorda tympani

Question 58

The chorda tympani leaves the ___________ canal and passes through the __________ ______ and the ________________ fissure to reach the tongue

Answer 58

facial middle ear tympanic

Question 59

Taste buds on the anterior 2/3 of the tongue are innervated by the __________ _______________ branch of the _________ __________.

Answer 59

chorda tympani | facial nerve

Question 60

The chorda tympani also carries _____________________ fibers to the submandibular ganglion.

Answer 60

parasympathetic

Question 61

The preganglionic parasympathetic fibers in the chorda tympani synapse in the _____________________ ganglion.

Answer 61

submandibular

Question 62

The chorda tympani carries both ____________ and ___________________ ____________________ fibers.

Answer 62

sensory | preganglionic parasympathetic

Question 63

The _________________ _____________________ fibers to the sphenopalatine ganglion leave the __________ _________ at its external genu.

Answer 63

preganglionic parasympathetic | facial nerve

Question 64

After leaving the __________ __________ the preganglionic parasympathetic fibers to the sphenopalatine ganglion enter the middle cranial fossa through the greater petrosal canal.

Answer 64

facial nerve

Question 65

The facial canal is connected to the middle cranial fossa by the __________ ___________ ________.

Answer 65

greater petrosal canal

Question 66

The facial nerve fibers to the sphenopalatine ganglion reach the ganglion by passing through the facial canal, _____________ _____________ __________, middle cranial fossa, foramen lacerum, and pterygoid canal in that order.

Answer 66

greater petrosal canal

Question 67

Parasympathetic fibers reach the sphenopalatine ganglion by way of the _________ _________, the _____________ _____________ _________, the ___________ ___________ fossa, the _____________ ___________, and the _______________ canal.

Answer 67

``` facial canal greater petrosal canal middle cranial foramen lacerum pterygoid ```

Question 68

The sphenopalatine ganglion is located at the anterior end of the ________________ ________.

Answer 68

pterygoid canal

Question 69

Postganglionic fibers from the sphenopalatine ganglion innervate the ____________ _________.

Answer 69

lacrimal gland

Question 70

The motor fibers of the facial nerve pass through the petrous part of the temporal bone inside the _________ ________ and exit through the stylomastoid foramen.

Answer 70

facial canal

Question 71

The facial canal connects the ____________ ___________ _________ to the ___________________ foramen.

Answer 71

internal acoustic meatus | stylomastoid

Question 72

Because the _________ _________ passes through the narrow facial canal, swelling in its sheath pinches the nerve and paralyzes the muscles it serves.

Answer 72

facial nerve

Question 73

Swelling of the sheath of the facial nerve causes paralysis of the muscles of ________ ____________, including the orbicularis oculi.

Answer 73

facial expression

Question 74

Closing or blinking the eye is impossible if the _______________ _________ muscle is paralyzed

Answer 74

orbicularis oculi

Question 75

Lack of blinking risks drying out and opacity of the ___________.

Answer 75

cornea

Question 76

The syndrome of unilateral paralysis of the facial muscles and dry eye on the same side due to swelling of the __________ of the _________ ________ is called Bell's palsy.

Answer 76

sheath facial nerve

Question 77

In order to prevent damage to the cornea, a patient with __________ _________ must close the affected eye with a bandage or put eye drops in every 15 minutes.

Answer 77

Bell's palsy

Question 78

The swelling of the sheath of the facial nerve usually subsides in 2 months and the symptoms of _________ ________ disappear.

Answer 78

Bell's palsy

Question 79

Although anti-inflammatory drugs may help, Bell's palsy usually resolves spontaneously in _____ ____________.

Answer 79

2 months

Question 80

Like most structures in the pons, the facial nucleus, superior salivatory nucleus, and superior half of the nucleus solitarius get their blood supply from small branches of the ____________ artery

Answer 80

basilar

Question 81

Occlusion of a circumferential branch of the basilar artery will usually infarct the facial nucleus and ________________ the ________ muscles.

Answer 81

paralyze | facial

Question 82

Because the internal genu of the facial nerve and the abducens nucleus share the ________ of the _____ ____________, the internal genu of the facial nerve passes through the abducens nucleus

Answer 82

floor | fourth ventricle

Question 83

Because the internal genu of the facial nerve and the abducens nucleus share the ________ of the _____ ____________, the internal genu of the facial nerve passes through the abducens nucleus

Answer 83

floor | fourth ventricle

Question 84

The abducens nucleus contains the lower motor neurons for the lateral rectus muscle of the eye which abducts one's ________.

Answer 84

gaze

Question 85

The abducens nerve exits the brainstem through the pontomedullary sulcus and reaches the ________ _________ muscle through the superior orbital fissure.

Answer 85

lateral rectus

Question 86

Because the abducens nucleus and the roots of the abducens nerve are close to the midline, occlusion of a paramedian branch of the ____________ ____________ will infarct the abducens nucleus and nerve.

Answer 86

basilar artery

Question 87

Infarction of either the _____________ ___________ or _____________ ___________ makes it impossible to turn the ipsilateral eye to its own side

Answer 87

abducens nucleus, abducens nerve

Question 88

Occlusion of a paramedian branch of the basilar artery will also infarct the ____________ ________ of the _________ __________ and paralyze the muscles of facial expression

Answer 88

internal genu | facial nerve

Question 89

The midline structures of the pons receive their blood supply from ________________ ___________ of the __________ ___________, and the lateral structures of the pons receive their blood supply from ____________________ ___________ of the __________ _____________.

Answer 89

paramedian branches basilar artery circumflex branches basilar artery

Question 90

Counting mediad, the vestibulocochlear nerve is the _______ cranial nerve, the facial nerve is the _______ cranial nerve, and the abducens nerve is the _______ cranial nerve

Answer 90

eighth seventh sixth

Question 91

The vestibulocochlear nerve is purely special ___________, and the abducens nerve is purely somatic __________, but the facial nerve contains branchial ___________, visceral ___________, and special __________ fibers.

Answer 91

``` sensory motor motor motor sensory ```