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Flashcards in Cranial nerves Deck (74)
0

CN II:
1.) Name
2.) Path of fibers
3.) Sensory? Motor? PS Fibers?
4.)Location of cell bodies --> Components (e.g. SVA, SSA, GSE, etc.), chief functions.
5.) Clinical (3):
1.) Lesion of optic NERVE
2.) Chiasma
3.) Tract

1.) Optic
2.) Fiber path: Exits the skull at the optic canal of the sphenoid bone (Rohen p.34, #3). Leaves the orbit through the optic canal and converge to form the optic chiasma. Synapse at the thalamus.
3.) Sensory: Yes (vision).
Motor: No.
PS fibers: No.
4.) Cell bodies located in the Ganglion cells of retina, SSA: Vision. Mediates the afferent limb of the PUPILLARY LIGHT REFLEX.
5.) CLINICAL:
1.) Lesion of optic NERVE (optic neuritis) may be caused by inflammatory, degenerative, demyelinating, or toxic disorders and result in blindness or diminished visual acuity and no direct pupillary light reflex.
2.) A lesion of the optic CHIASMA (where the "H" meets in the middle) produces bitemporal heteronymous hemianopsia or tunnel vision (only see out of the opposite [central] portion of each eye).
3.) A lesion of the optic TRACT (a lower leg of the "H") produces contralateral homonymous hemianopsia (only see out of 1/2 of each eye...the same half, i.e. both right half, or both left half). *IF YOU INJURE THE RIGHT PORTION, LEFT VISION IS AFFECTED!*

1

CN I:
1.) Name
2.) Course of fibers
3.) Sensory? Motor? PS Fibers?
4.) Location of cell bodies --> Components (e.g. SVA, SSA, GSE, etc.), chief functions.
5.) Clinical

1.) Olfactory.
2.) Passes through the foramina in the cribiform plate of the ethmoid bone and enters the olfactory bulb where they synapse.
3.) Sensory: Yes (smell).
Motor: No.
PS fibers: NO.
4.) Cell bodies in the Nasal mucosa, SVA: Smell.
5.) CLINICAL: Lesion of the olfactory nerve may occur as a result of ethmoidal bone fracture and cause ANOSMIA, i.e. loss of olfactory sensation. Many people with anosmia may complain of loss or alteration of taste.

2

The optic nerve fibers arise from ______, and synapse at the _____

Arise from ganglion cells in the RETINA, synapse at the THALAMUS.

3

CN III: See Rohen p.69 for good view.
1.) Name
2.) Location of fibers.
3.) Location of cell bodies --> a.) PS b.) Somatic
4.) a.) Sensory? b.) Motor? c.) PS Fibers?
5.)
a.) somatic
b.) PS (presynaptic and postsynaptic) fiber components (e.g. SVA, SSA, GSE, etc.). Muscles? Chief functions?
6.) Clinical (4)

1.) Oculomotor
2.) Fibers extend from the ventral midbrain and enter the orbit through the *superior orbital fissure* within the tendinous ring (?).
3.)
a.) PS bodies: Edinger-Westphal nucleus.
b.) Somatic bodies: Nucleus CN III (midbrain).
4.)
a.) Sensory: No.
b.) Motor: Yes.
c.) PS fibers: Yes --> Mediates EFFERENT LIMB of PUPILLARY LIGHT REFLEX.
5.)
a.) Nucleus CN III (midbrain), GSE (somatic): Eye movements via extraocular muscles **i.e. superior, inferior, and medial recti, inferior oblique, and lecvator palpebrae superioris mm.**
b.) Presynaptic--> Preganglionic PS GVE fibers.
Postsynaptic--> Ciliary ganglia. GVE: Constriction of pupil (sphincter pupillae muscle) and accommodation (ciliary muscle).

6.) CLINICAL: Lesion of the oculomotor nerve causes:
1.) PTOSIS: Paralysis of ocular muscles INCLUDING the *levator palpebrae superioris* (ptosis) because of damage of GSE fibers. Causes drooping of the eyelid(s).
2.) MYDRIASIS: Paralysis of *sphincter pupillae* resulting in DILATION of the pupil (myDriasis = Dilation), and...
3.) Paralysis of ciliary muscles, resulting in loss of accommodation because of damage of the parasympathetic GVE fibers.
4.) Lesion also causes loss of *pupillary light reflex* because of damage of **parasympathetic fibers** that mediate the efferent limb of the pupillary light reflex.
5.) Oculomotor nerve paralysis: Characteristic "down and out" position of the affected eye caused by unantagonized superior oblique by the paralyzed superior rectus and inferior oblique.

4

Which muscles are innervated by CN III and by what division?
Where are its preganglionic PS GVE fiber cell bodies located? Where are the fibers derived from?
Postganglionic?

The extraocular muscles (GSE fibers): SCRIL
1.) Recti x3 (superior, medial, inferior) --> inferior division of oculomotor nerve.
2.) Inferior oblique --> inferior division of oculomotor nerve.
3.) Levator palpebrae superioris -- (PALPEBRAE = EYELID) --> inferior division of oculomotor nerve.

4.) Ciliary muscle --> (postganglionic PS via short ciliary nerves).
5.) Sphincter pupillae --> (postganglionic PS via short ciliary nerves).

-Somatic bodies in the midbrain.
-Preganglionic PS cell bodies in the EDINGER-WESTPHAL nucleus (GVE).
Postganglionic PS fibers derived from the ciliary ganglion that run in the SHORT CILIARY NERVES (Rohen p.68, #6)...to supply the SPHINCTER PUPILLAE (for miosis, i.e. constriction of the pupil) and the CILIARY MUSCLE (accommodation).

5

What muscles do the short ciliary nerves supply? Good pic on p.68 Rohen.

Sphincter pupillae, ciliary muscle.

6

CN IV:
1.) Name
2.) Location of fibers
3.) Location of cell bodies
4.) Sensory? Motor? PS Fibers?
5.) Components (e.g. SVA, SSA, GSE, etc.). Muscle(s)? Chief functions.
6.) Clinical

1.) Trochlear nerve
2.) Fibers emerge from the *DORSAL ASPECT* of the brain stem. Passes through the *lateral wall of the CAVERNOUS SINUS during its course, and exits the skull (enters the orbit) through the SUPERIOR ORBITAL FISSURE.
3.) Cell bodies: Nucleus CN IV (midbrain).
4.) Sensory: No.
Motor: Yes.
PS fibers: No.
5.) GSE: Eye movements (SUPERIOR OBLIQUE MUSCLE = Abduction, depression, and medial rotation).

6.) CLINICAL: Lesion of the trochlear nerve causes paralysis of the superior oblique muscle of the eye, causing DIPLOPIA (double vision) when looking down. It may be caused by severe head injuries because of its long intracranial course.

6

What is the difference between compression and vascular lesions of CN III?

Compression lesions tend to involve the pupil, while vascular lesions SPARE the pupil.

7

1.) Which muscle(s) does CN IV innervate? What is its action?
2.) What makes CN IV different from all other CN's?

1.) Superior oblique muscle: ABduction, medial rotation, and depression of the eyeball.
2.) It is the only CN that emerges from the DORSAL ASPECT OF THE BRAIN STEM.

8

CN V (V1, V2, V3):
1.) Name
2.) Branches (3) with their function and course of fibers, cell body location (2).
3.) Exits skull (3 places)
4.) Sensory? Motor? PS Fibers?
5.) Components (e.g. SVA, SSA, GSE, etc.), muscles, and chief functions.
6.) Clinical (5)

1.) Trigeminal nerve

2.)
i.) V1, Ophthalmic nerve (GSA), Cell bodies in trigeminal ganglion: Runs in the dura of the lateral wall of the cavernous sinus and enters the orbit through the superior orbital fissure.
-Sensory innervation to the EYEBALL, TIP OF NOSE, SKIN OF FACE ABOVE THE EYE.
-Mediates AFFERENT limb of the corneal reflex via the nasociliary branch. *Facial nerve mediates the efferent*

ii.) V2, Maxillary nerve (GSA), Cell bodies in trigeminal ganglion: Passes through the lateral wall of the cavernous sinus and through the FORAMEN ROTUNDUM (inferior to the superior orbital fissure).
-Provides sensory (GSA) innervation to the midface (below eye, but above upper lip), palate, paranasal sinuses, and maxillary teeth.
-Cell bodies in the trigeminal ganglion.
-Mediates the afferent limb of the SNEEZE REFLEX (irritation of nasal mucosa). *Vagus for efferent*

iii.) V3, Mandibular nerve (SVE, and GSA), Cell bodies in motor nucleus and trigeminal ganglion: Passes through the FORAMEN OVALE (inferolateral to the foramen rotundum) .
-Supplies motor innervation to six muscles (MMATT).
-Sensory innervation (GSA) for lower part of face (below lower lip and mouth), scalp, jaw, mandibular teeth, and anterior 2/3 of tongue.
-Mediates the afferent AND efferent limbs of the JAW JERK REFLEX.

3.) Exits: Superior orbital fissure; foramen rotundum and foramen ovale

4.) Sensory: Yes (general sensation).
Motor: Yes.
PS fibers: No.
5.)
a.) Motor nucleus CN V (pons), SVE: Muscles of mastication (temporalis, masseter, lateral & medial pterygoid), mylohyoid, anterior belly of digastric, tensor veli palantini, and tensor tympani muscles.
b.) Trigeminal ganglion, GSA: Sensation on head --> face, oral, nasal, and sinus mucosa; teeth; anterior 2/3 of the tongue.

6.) CLINICAL:
1.) Lesion of the trigeminal nerve causes sensory loss of on the face and motor (SVE) loss of muscles of mastication with deviation of the mandible TOWARD the side of the lesion.
2.) Lesion of the lingual nerve near the oral cavity causes loss of general and taste sensation to the anterior 2/3 of the tongue and salivary secretion from submandibular and sublingual glands.
3.) Lesion of the ophthalmic division cannot mediate the afferent limb of the corneal reflex by way of the nasociliary branch (the facial nerve mediates the efferent limb).
4.) Lesion of the maxillary division cannot mediate the afferent limb of the sneeze reflex (vagus nerve mediates the efferent limb).
5.) Lesion of the mandibular division cannot mediate the afferent and efferent limbs of the jaw jerk reflex.

9

Give the name and functions for the branches/nerves (4) of the ophthalmic division of CN V.

1.) Lacrimal nerve: Supplies the lacrimal gland, the conjunctiva, and the skin of the upper eyelid. Carries parasympathetic information.

2.) Frontal nerve: Divides into the supraorbital and supratrochlear nerve and supplies the scalp, forehead, frontal sinus, and upper eyelid.

3.) Nasociliary nerve: Gives rise to -->
a.) Communicating branch to the ciliary ganglion.
b.) Short ciliary nerves, which carry postganglionic parasympathetic and sympathetic and afferent fibers.
c.) Long ciliary nerves, which carry postganglionic sympathetic fibers to the DILATOR PUPILLAE and afferent fibers from the IRIS and CORNEA.
d.) Posterior ethmoidal nerve: Supplies the sphenoidal and posterior ethmoidal sinuses.
e.) Anterior ethmoidal nerve: Supplies the anterior ethmoidal air cells and divides into the internal and external nasal branches.
f.) Infratrochlear nerve: Innervates the EYELIDS, CONJUNCTIVA, SKIN OF THE NOSE, and LACRIMAL SAC.

4.) Meningeal branch: Supplies the dura in the anterior cranial fossa.

11

Give the name and functions of the branches (6) from the maxillary division of CN V (4 a-b, 6 a-f).

1.) Meningeal branch: Innervates the dura mater of the middle cranial fossa.
2.) Pterygopalatine (communicating) nerve: Connects to the pterygopalatine ganglion.
3.) Posterior-superior alveolar nerve: Innervates the cheeks, gums, molar teeth, and maxillary sinus.
4.) Zygomatic nerve: Divides into the
a.) Zygomaticofacial and...
b.) Zygomaticotemporal nerves. *This carries postganglionic parasympathetic fibers and JOINS THE LACRIMAL NERVE (from V1) for lacrimal secretion*
5.) Infraorbital nerve: Gives rise to the middle and anterior-superior alveolar nerves that supply the maxillary sinus, teeth, and gums. It then emerges through the infraorbital foramen and divides in the face into the INFERIOR PALPEBRAL, NASAL, and SUPERIOR LABIAL BRANCHES.
6.) Branches via the pterygopalatine ganglion: Includes -->
a.) Orbital branches: Supply the orbit and posterior ethmoidal and sphenoidal sinuses.
b.) Pharyngeal branch: Supplies the roof of the pharynx and sphenoidal sinus.
c.) Posterior-superior nasal branches: Innervate the nasal septum, posterior ethmoidal air cells, and superior & middle conchae.
d.) Greater palatine nerve: Innervates the HARD PALATE, and inner surface of the maxillary gingiva.
e.) Lesser palatine nerve: Innervates the SOFT PALATE and palatine tonsil. Contains sensory (GVA and taste) fibers. *Taste via greater petrosal n. of VII*
f.) Nasopalatine nerve: Supplies the nasal septum, the hard palate, and the gums.

12

Give the name and functions of the branches (6) from the maxillary division of CN V (4 a-b, 6 a-f).

1.) Meningeal branch: Innervates the dura mater of the middle cranial fossa.
2.) Pterygopalatine (communicating) nerve: Connects to the pterygopalatine ganglion.
3.) Posterior-superior alveolar nerve: Innervates the cheeks, gums, molar teeth, and maxillary sinus.
4.) Zygomatic nerve: Divides into the
a.) Zygomaticofacial and...
b.) Zygomaticotemporal nerves. *This carries postganglionic parasympathetic fibers and JOINS THE LACRIMAL NERVE (from V1) for lacrimal secretion*
5.) Infraorbital nerve: Gives rise to the middle and anterior-superior alveolar nerves that supply the maxillary sinus, teeth, and gums. It then emerges through the infraorbital foramen and divides in the face into the INFERIOR PALPEBRAL, NASAL, and SUPERIOR LABIAL BRANCHES.
6.) Branches via the pterygopalatine ganglion: Includes -->
a.) Orbital branches: Supply the orbit and posterior ethmoidal and sphenoidal sinuses.
b.) Pharyngeal branch: Supplies the roof of the pharynx and sphenoidal sinus.
c.) Posterior-superior nasal branches: Innervate the nasal septum, posterior ethmoidal air cells, and superior & middle conchae.
d.) Greater palatine nerve: Innervates the HARD PALATE, and inner surface of the maxillary gingiva.
e.) Lesser palatine nerve: Innervates the SOFT PALATE and palatine tonsil. Contains sensory (GVA and taste/SVA) fibers. *Taste via greater petrosal n. of VII*
f.) Nasopalatine nerve: Supplies the nasal septum, the hard palate, and the gums.

13

CN VII:
1.) Name
2.) Cranial exit
3.) Sensory? Motor? PS Fibers?
4.) Cell bodies --> Components (e.g. SVA, SSA, GSE, etc.), chief functions, muscles. (a, b, c)
5.) Clinical

1.) Facial
2.) Exits: Stylomastoid foramen
3.) Sensory: Yes (taste).
Motor: Yes.
PS fibers: Yes.
4.) a.) Motor nucleus CN VII (pons), SVE: Muscle of facial expression, posterior belly of digastric, stylohyoid, and stapedius muscle.
b.) Superior salivatory nucleus (pons), GVE: Lacrimal and salivary excretion.
c.) Geniculate ganglion, SVA: Taste from anterior 2/3 of tongue and palate. GVA: Sensation from palate. GSA: Auricle and external acoustic meatus.
5.) CLINICAL: Lesion of the facial nerve causes loss of SVE fibers to innervate the muscles of facial expression (Bell's palsy); SVA (taste) fibers from the anterior 2/3 of the tongue; parasympathetic GVE fibers for the lacrimal, submandibular, sublingual, nasal, and palatine glands; GVA fibers to the palate and nasal mucosa, carotid sinus, and carotid body; and GSA fibers from the external acoustic meatus and the auricle. Lesion causes loss of mediation of the efferent limb of the corneal blink reflex.

14

CN VIII:
1.) Name
2.) Cranial exit
3.) Sensory? Motor? PS Fibers?
4.) Cell body? --> Components (e.g. SVA, SSA, GSE, etc.), chief functions (a, b)
5.) Clinical

1.) Vestibularcochlear
2.) Does not leave skull
3.) Sensory: Yes (hearing and balance).
Motor: Yes.
PS fibers: Yes.
4.)
a.) Vestibular ganglion, SSA: Equilibrium.
b.) Spiral ganglion, SSA: Hearing.
5.) CLINICAL: Lesion of the vestibulocochlear nerve causes loss of SSA fibers to hair cells of the cochlea (organ of Corti), the ampullae of the semicircular ducts, and the utricle and saccule, resulting in loss of hearing, vertigo (dizziness, loss of balance), and tinnitus (ringing or buzzing in the ear).

15

CN: IX
1.) Name
2.) Cranial exit
3.) Sensory? Motor? PS Fibers?
4.) Location of cell bodies --> Components (e.g. SVA, SSA, GSE, etc.), chief functions, muscles. (a-e)
5.) Clinical

1.) Glossopharyngeal
2.) Exits: Jugular foramen
3.) Sensory: Yes (taste).
Motor: Yes.
PS Fibers: Yes.
4.)
a.) Nucleus ambiguus (medulla), SVE: Elevation of pharynx (stylopharygeus muscle).
b.) Inferior salivary nucleus (medulla), GVE: Secretion of saliva (parotid gland).
c.) Inferior ganglion, GVA: Carotid sinus and body, tongue, pharynx, and middle ear.
d.) Inferior ganglion, SVA: Taste from posterior 1/3 of tongue.
e.) Superior ganglion, GSA: External ear.
5.) CLINICAL: Lesion of the glossopharyngeal nerve causes loss of SVE fibers to the stylopharyngeus muscle; SVA (taste) fibers to the posterior 1/3 of the tongue and vallate papillae; GVE fibers to the optic ganglion; GVA fibers to the pharynx, posterior 1/3 of the tongue, tympanic cavity, the mastoid antrum and air cells, and the auditory tube; and GSA fibers to the external ear. Lesion cannot mediate the afferent limb of the gag (pharyngeal) reflex.

16

CN VI (p.1068 Moore):
1.) Name
2.) Cranial exit
3.) Location of cell bodies
4.) Sensory? Motor? PS Fibers?
5.) Components (e.g. SVA, SSA, GSE, etc.), chief functions.
6.) Clinicala

1.) Abducens
2.) Exits: Superior orbital fissure
3.) Nucleus CN VI pons
4.) Sensory: No.
Motor: Yes.
PS fibers: No.
5.) Nucleus CN VI (pons), GSE: Eye movement (lateral rectus muscle).
6.) CLINICAL: Lesion of the abducens nerve causes paralysis of the lateral rectus muscle of the eye, causing medial deviation of the affected eye. It may result from a brain tumor or septic thrombosis in the cavernous sinus.

16

CN X:
1.) Name
2.) Cranial exit
3.) Sensory? Motor? PS Fibers?
4.) Location of cell bodies --> Components (e.g. SVA, SSA, GSE, etc.), chief functions, muscles. (a-e)
5.) Clinical

1.) Vagus
2.) Exits: Jugular foramen
3.) Sensory: Yes (taste).
Motor: Yes.
PS fibers: Yes.
4.)
a.) Nucleus ambiguus (medulla), SVE: Muscles of pharynx, larynx, and palate.
b.) Dorsal nucleus (medulla), GVE: Smooth muscles and glands in thoracic and abdominal viscera.
c.) Inferior ganglion, GVA: Sensation of lower pharynx, larynx, trachea, and other viscerae.
d.) Inferior ganglion, SVA: Taste on epiglottis.
e.) Superior ganglion, GSA: Auricle and external auditory meatus.
5.) CLINICAL: Lesion of the vagus nerve causes dysphagia (difficulty swallowing) resulting from lesion of pharyngeal branches; numbness of the upper part of the larynx and paralysis of cricothyroid muscle resulting from lesion of the superior laryngeal nerve; and hoarsness, dysphonia (difficulty speaking), aphonia (loss of voice), and numbness of the lower part of the larynx resulting from lesion of the recurrent laryngeal nerve. Lesion results in deviation of the uvula toward the opposite side of the lesion on phonation. Lesion cannot mediate the afferent and efferent limbs of the cough reflex and the efferent limbs of the gag reflex and sneeze reflex. In addition, lesion causes loss of SVE fibers to muscles of the larynx, pharynx (except stylopharyngeus), and palate (except the tensor veli palantini); SVA (taste) fibers to the taste buds on the epiglottis; and GVE and GVA fibers to thoracic and abdominal visceral organs.

17

CN XI:
1.) Name
2.) Cranial exit
3.) Sensory? Motor? PS Fibers?
4.) Location of cell bodies --> Components (e.g. SVA, SSA, GSE, etc.), chief functions, muscles.
5.) Clinical

1.) Accessory
2.) Exits: Jugular foramen
3.) Sensory: No.
Motor: Yes.
PS fibers: No.
4.) Spinal cord (cervical), SVE: Sternocleidomastoid and trapezius muscle.
5.) CLINICAL: Lesion of the accessory nerve causes loss of SVE fibers to the sternocleidomastoid and trapezius muscles. The arm cannot be abducted beyond the horizontal position as a result of an inability to rotate the scapula. Lesion also causes torticollis because of paralysis of the sternocleidomastoid and shoulder drop from paralysis of the trapezius.

18

CN XII:
1.) Name
2.) Cranial exit
3.) Sensory? Motor? PS Fibers?
4.) Location of cell bodies --> Components (e.g. SVA, SSA, GSE, etc.), chief functions, muscles.
5.) Clinical

1.) Hypoglossal
2.) Exits: Hypoglossal canal
3.) Sensory: No.
Motor: Yes.
PS fibers: No.
4.) Nucleus CN XII (medulla), GSE: Muscles and movements of the tongue.
5.) CLINICAL: Lesion of the hypoglossal nerve cause loss of GSE fibers to all of the intrinsic and extrinsic muscles of the tongue except the palatoglossus, which is supplied by the vagus nerve. Lesion causes deviation of the tongue toward the injured side on protrusion. Hence, the mnemonic to remember the deviation side is "you lick your wounds."

19

Trace the path of CN VII

Enters at the *internal acoustic meatus*, the facial canal in the temporal bone, and emerges from the stylomastoid foramen.

20

Which muscle(s) does CN VI supply? What is the function?

Lateral rectus muscle: Abduction of the pupil.

21

Which nerve parallels the internal carotid artery in the cavernous sinus?

Abducens

22

What types of fibers does CN VII carry (5)?
a.) Where do each of the nuclei lie?
b.) What is their function?

1.) SVA --> Special sensory (taste):
a.) Nuclei in the geniculate ganglion.
b.) Chorda tympani joins with lingual nerve.

2.) GSA --> Somatic (general) sensory:
a.) Nuclei in the geniculate ganglion.
b.) Afferent sensation from the external acoustic meatus and the auricle.

3.) SVE --> Somatic (branchial) motor:
a.) Nuclei in the pons.
b.) Fibers to the STAPEDIUS, AURICLE, and OCCIPITALIS. Muscles of facial expression.

4.) GVE --> Visceral (parasympathetic) motor:
a.) Nuclei in the superior salivatory nucleus (pons).
b.) Innervates the submandibular, sublingual, and lacrimal glands.

5.) GVA --> General sensory:
a.) Nuclei lie in the geniculate ganglion.
b.) Afferent sensation from palate and nasal mucosa.

23

What types of fibers does CN VII carry (5)?
a.) Where do each of the nuclei lie?
b.) What is their function?

1.) SVA --> Special sensory (taste):
a.) Nuclei in the geniculate ganglion.
b.) Taste from anterior 2/3 of tongue and palate (chorda tympani joins with lingual nerve).

2.) GSA --> Somatic (general) sensory:
a.) Nuclei in the geniculate ganglion.
b.) Sensation from the external acoustic meatus and the auricle.

3.) SVE --> Somatic (branchial) motor:
a.) Nuclei in the pons.
b.) Fibers to the Posterior belly of digastric, stylohyoid, stapedius, and muscles of facial expression.

4.) GVE --> Visceral (parasympathetic) motor:
a.) Nuclei in the superior salivatory nucleus (pons).
b.) Submandibular, sublingual, and lacrimal gland secretion.

5.) GVA --> General sensory:
a.) Nuclei lie in the geniculate ganglion.
b.) Sensation from palate and nasal mucosa.

24

What are the two major divisions of CN VII? What do they do?

1.) Primary root (facial nerve proper): Larger of the two. Innervates the muscles of facial expression.

2.) Intermediate nerve: Carries taste, parasympathetic, and somatic sensory fibers.

25

1.) Where does CN VII exit the skull?
2.) What nerves does CN VII give rise to?

1.) Stylomastoid foramen
2.) Greater petrosal nerve, nerve to stapedius, chorda tympani nerve, posterior auricular branch. Also, PAROTID PLEXUS.

26

Which nerve forms the parotid plexus? What does it give rise to?

CN VII. The parotid plexus gives rise to FIVE terminal motor branches: Temporal, zygomatic, buccal, marginal mandibular, and cervical.

*Mnemonic: Ten Zebras Bit My Carrot*

27

1.) Which muscles (besides those of facial expression and auricular) does CN VII innervate?
2.) Which glands does CN VII innervate? Via what type of fibers? Do any other nerves participate?

1.) Posterior belly of digastric, Stylohyoid, Stapedius
2.) - a.) Lacrimal glands via --> Visceral presynaptic parasympathetic fibers to the PTERYGOPALATINE ganglion. POSTSYNAPTIC VIA CN V2!!!!
b.) Sublingual and submandibular salivary glands via --> Submandibular ganglion (same type of fibers as above). POSTSYNAPTIC VIA CN V3!!!

28

1&2.) Describe the relationship between CN VII and CN V (2)
3.) What type of fibers synapse in the ganglia of CN VII?

1.) CN VII provides the presynaptic parasympathetic fibers to the pterygopalatine ganglion. The POSTSYNAPTIC fibers are provided by CN V2 (maxillary branch of trigeminal).

2.) CN VII sends the same fibers to the submandibular ganglion, and CN V3 (mandibular branch of trigeminal) distributes the POSTSYNAPTIC FIBERS.

3.) Parasympathetic --> sympathetic and other fibers pass through them.

29

How is CN VII associated with taste?

Fibers of the chorda tympani join the LINGUAL NERVE of CN V3 to convey taste sensation from the ANTERIOR 2/3 of the tongue and soft palate.

30

1.) What type of fibers does CN VIII carry?
2.) What is their function?
3.) Where are the nuclei?
4.) What two nerves does it separate into and where?

1.) SSA (special sensory, somatic afferent)
2.) Hearing, equilibrium, and motion (acceleration/deceleration)
3.) Medulla and pons
4.) The vestibular and cochlear in the internal acoustic meatus

31

The peripheral processes of the vestibular nerve extend to the what? (three structures) What do the structures do?

1&2.) The MACULAE of the UTRICLE and SACCULE (sensitive to linear acceleration and the pull of gravity relative to the position of the head).

3.) Cristae of the ampullae of the semicircular ducts (sensitive to rotational acceleration).

*p.1072 Moore*

32

What structure do the peripheral processes of the cochlear nerve neurons extend to? What does it do?

The spiral organ for the SENSE OF HEARING

33

Which nerve innervates the posterior belly of digastric?

Facial nerve CN VII

34

Which CN supplies SCM and trapezius?

CN XI, spinal accessory

35

Which nerve supplies the infrahyoid muscles?

Ansa cervicales

36

Which CN supplies the stylopharyngeus muscle?

Glossopharyngeal CN IX

37

If a patient has an earache, which CN is carrying the pain sensation?

CN IX, glossopharyngeal

38

GVE is the same thing as saying what?

Autonomic

40

What muscle does CN IX innervate?

Stylopharyngeus m.

41

What nerves mediate the sneeze reflex (afferent and efferent)?

V2 = afferent
X = efferent
p.457 BRS

42

Which nerves mediate the corneal reflex?

Long ciliary (V1) = afferent
VII = efferent

43

Which nerve(s) mediate the jaw jerk reflex?

V3 = Afferent and efferent

44

What type of injury would cause medial deviation of the eye and how?

Cavernous sinus thrombosis – because it would lesion CN VI (Abducens), the action of which is lateral deviation (ABduction) of the eye. Loss of this muscle/function would result in medial deviation of the affected eye.
#66

45

1.) What is the sensory ganglion for the facial nerve?
2.) What types of fibers does it receive (3)?

1.) Geniculate ganglion
2.) SVA (taste), GVA (sensation from palate), GSA (sensation from the auricle and external acoustic meatus).
pp.452-453 BRS, #72

47

Which nerve(s) mediate the gag reflex?

IX (GVA) = Afferent
X = Efferent
#89

48

What are GSE fibers for and which CNs carry them?

GSE (General Somatic Efferent): Motor to skeletal muscles of eye and tongue. Carried by CNs III, IV, VI, XII.
p.453 BRS

49

What muscles does CN X supply and via what type of fibers?

All muscles of pharynx and larynx *except stylopharyngeus*.

All muscles of palate *except tensor veli palatini*.
#97

50

1.) What is the manifestation in the uvula of a vagus nerve lesion?
2.) Which CN X branch and fiber type is responsible for this?

1.) Deviation of uvula towards the *opposite side* of the lesion on phonation.
2.) Pharyngeal branch (SVE).
#97

51

Which nerve(s) innervates the following: Tensor veli palatini, tensor tympani, levator veli palatini.

Tensors veli palatini and tympani = V3.
Levator veli palatini = Vagus via pharyngeal plexus.

52

Which nerve and fiber type provides sensory and taste innervation to the posterior-most portion of the tongue, epiglottis, and upper larynx?

CN X (GVA and SVA) via *internal laryngeal n.*
#99

53

What vocal manifestations would be the result of a vagus n. lesion (4) and which branch?

Recurrent laryngeal n.
1.) Hoarsness
2.) Dysphonia
3.) Aphonia
4.) Numb lower larynx (ipsilateral)
#102

54

Lesion of which CN would affect the upper larynx and which branch in particular? What are the effects (2)?

Vagus – Superior laryngeal n.
1.) Numb upper larynx (internal laryngeal nerve).
2.) Monotone phonation (due to cricothyroid m. paralysis by external laryngeal nerve).
#102

55

What reflex actions would be lost in the case of vagus n. lesion (3)?

1.) Afferent and efferent limbs of cough reflex.
2-3.) Efferent limbs of the gag (pharyngeal) and sneeze reflex.
#103

56

1.) In the case of a CN XI lesion, what neck motion would be deficient/absent?
2.) Any other motions not pertaining to neck motions (2)?

1.) Turning neck to *opposite* side —> Due to SCM.
2.)
a.) Difficulty shrugging due to trapezius weakness.
b.) Ipsilateral arm cannot be abducted beyond the horizontal as a result of inability to rotate scapula.
#109

57

1.) CN XII loops around the _______ artery and the _______ to pass between the _______ and _________ vessels.
2.) It runs deep to the ________ and _______ muscles to enter the ________ triangle.

1.) -loops around the occipital artery and the carotid bifurcation.
-pass between the carotids and internal jugular vessels.
2.) digastric posterior belly and stylohyoid muscles to enter the submandibular triangle.
p.463 BRS

58

Not strictly part of the hypoglossal nerve, it also carries ______ fibers from C1 to supply the _________________ and the nerve to both the _______ and _______ muscles.

-motor (GSE) fibers from C1 to supply the upper root of the ansa cervicalis.
-nerve to both the thyrohyoid and geniohyoid muscles.
p.463 BRS

59

1.) Where does the SNS innervation in the pterygopalatine ganglion come from?
2.) What is this nerves fate upon exiting the pterygoid canal?

1.) Deep petrosal nerve (postganglionic SNS fibers) derived from the superior cervical ganglion, via plexus on the internal carotid artery.
2.) The deep petrosal n. merges with the greater petrosal nerve within the pterygoid canal to form the nerve of pterygoid canal, aka the *vidian nerve*.
#121

60

What ganglion is sensory information from the anterior 2/3 of the tongue destined for? Via what route?

Geniculate ganglion (via SVA fibers on chorda tympani).
p.459 BRS

61

A lesion of which CN would result in hyperacusis (sensitivity to loud sounds)?

Facial
#36 Gray's

62

What are the components of CN III?

GVE – PSNS to ciliary body and sphincter pupillae (pupil constriction).
GSE – To extra-ocular muscles.

63

Aneurysm of which Circle of Willis arteries can damage CN III? Result?

PCA, SCA, PCoA, and cavernous sinus —> All cause Down and out.

64

What causes ptosis (which muscle and CN)?

Ptosis = paralysis of levator palpebrae superioris (CN III)
#11 Lobo

65

What is mydriasis?

Dilated pupil due to lack of PSNS to sphincter pupillae (CN III).
#11 Lobo

66

When does diplopia occur with CN IV damage?

When the person looks toward the side of the affected eye.

67

What is the position of the eye ball for inferior oblique to perform ONLY elevation?

ADducted (medial rotation) ≈ 51˚ —> angle of gaze coinciding with angle of muscle.
p.902 Moore

68

What is the position of the eye ball for superior oblique to perform ONLY depression?

ADducted (medial rotation) ≈ 51˚ —> angle of gaze coinciding with angle of muscle.
p.902 Moore

69

What is the position of the eye ball for inferior rectus to perform ONLY depression?

ABducted (lateral rotation) ≈ 23˚ —> angle of gaze coinciding with angle of muscle.
p.902 Moore

70

What is the position of the eye ball for superior rectus to perform ONLY elevation?

ABducted (lateral rotation) ≈ 23˚ —> angle of gaze coinciding with angle of muscle.
p.902 Moore

71

What are other names for medial and lateral rotation of the eye?

Medial rotation = Intortion
Lateral rotation = Extortion
p.899 Moore

72

Give the three actions for both inferior and superior rectus muscles.

1.) Inferior Rectus: Depression, extortion/lateral rotation, ADduction.
2.) Superior Rectus: Elevation, intortion/medial rotation, ADduction.
p.899 Moore

73

Give the three actions for both superior and inferior oblique muscles.

1.) Superior oblique: Depression, intortion/medial rotation, ABduction.
2.) Inferior oblique: Elevation, extortion/lateral rotation, ABduction.
p.901 Moore

74

1.) What nerve carries the afferent limbs of the corneal reflex (from iris and cornea)?
2.) What else does this nerve carry?

1.) Long ciliary
2.) Post-ganglionic sympathetic to dilator pupilae.
p.456 BRS