2nd half of CN lecture

Question 1

Is CN VII motor, sensory, or both?

Answer 1

Both

Question 2

You know that CN VII mediates facial expression by motor to muscles, but what 2 parasympathetic actions does it carry?

Answer 2

Salivation and lacrimation

Question 3

What are the two main areas of sensory for CN VII?

Answer 3

Behind the ear/ concha and the anterior 2/3 of the tongue

Question 4

How many branches are there of the facial nerve and what are their names?

Answer 4

5. Temporal, Zygomatic, Buccal, Mandibular, Cervical To Zanzibar By Motor Car

Question 5

What are the 3 ganglions associated with CN VII? (2 in one

Answer 5

Geniculate Ganglion - Pterygopalatine ganglion - Lacrimal gland Geniculate Ganglion - Submandibular ganglion - Submandibular/ sublingual glands

Question 6

What is the pathway of facial motor nerves?

Answer 6

Facial motor nucleus - VII nerve - IAC - Facial Canal - Stylomastoid Foramen - passes through the parotid gland - muscles

Question 7

True/False: CN VII has bilateral innervation the for whole face.

Answer 7

False. Bilateral is only the forehead. Stroke (UMN) will have forehead sparing, Bell’s Palsy (LMN) won’t.

Question 8

Describe the special sensory components

Answer 8

Taste from Lingual N to Chorda Tympani to Facial N

Question 9

CN VII is involved in the corneal blink reflex. Efferent or afferent?

Answer 9

Efferent (exit) Afferent is V1

Question 10

If you have abnormal taste on the anterior 2/3 of the tongue, where would the lesion be?

Answer 10

Lingual N or Chorda Tympani

Question 11

Hyperacusis (sensitivity to certain frequencies/ volume) can happen with paralysis of ______ muscle

Answer 11

Stapedius

Question 12

Bell’s Palsy is a LMN lesion of CN VII. What would you expect to see?

Answer 12

Paralysis and possibly atrophy of the muscles of facial expression Uncontrolled tearing Lips cannot be held together and food will spill out on affected side Loss of the efferent limb of the CORNEAL REFLEX - cannot close eye

Question 13

It matters if you cut above or below where the Chorda tympani joins the lingual nerve. Why?

Answer 13

Cut Lingual N ABOVE where chorda tympani joins spares CN VII and only cuts CN V.

You would spare taste, but lose general sensation from anterior 2/3

Question 14

A Schwannoma can effect what 2 nerves?

Answer 14

CN VII and CN VIII

Question 15

Vestibulocochlear Nerve VIII exits the brain stem at the ____________ _______ and enters _____ _____ ____into the _______ ____

Answer 15

Cerebellopontine Angle Internal Auditory Canal Petrous Bone

Question 16

Cn VIII regulates compensatory eye movements via what?

Think about where CN III, IV, and VI go.

Answer 16

Medial Longitudinal Fasciculus

Question 17

How would you test CN VII?

Answer 17

–Observe nystagmus during EOM Test

–Romberg Test: Patient falls to side of vestibular hypofunction

•Also seen in dorsal column disease - Lues

–Caloric Testing

–Coordination Examinations

Question 18

Name 3 lesions of CN VIII

Answer 18

–Acoustic Neuroma and aneurysms

–Meningiomas

–MS

Question 19

Describe bone and air conduction. Where and how are those waves transmitted? Which do you expect to be louder?

Answer 19

• Conductive hearing loss: Disorder of the external and/or middle ear impairing conduction of sound to the inner ear.
• Sensorineural hearing loss: Disorder of the inner ear, cochlear nerve, or its central connections impairing transmission of nerve impulses to the brain.
• Air conduction describes the normal hearing pathway from the external ear to the junction of the middle and inner ear.
• Bone conduction bypasses the external and middle ear. The bones of the skull vibrate and stimulate the cochlea directly.
• Normally, air conduction is more sensitive than bone conduction

Question 20

What are the two tests to study for bone and air conduction?

Answer 20

Weber and Rinne

Question 21

What is the area where the ossicles are held called?

Answer 21

Vestibule (antechamber)

Question 22

If you get a tumor on CN VIII what 3 symptoms would you have?

Answer 22

Deafness, Vertifo, Tinnitis

Question 23

Glossopharyneal CN IX mediates what?

Answer 23

taste, salivation, and swallowing

Question 24

CN IX is M, S, or B?

Where does it exit the skull?

Answer 24

Both!

Jugular Foramen

Question 25

What are the sensory components of CN XI?

Answer 25

Carotid Body Chemoreceptors/ Baroreceptors (Afferent for carotid sinus reflex) Sensory from the oropharynx, posterior 1/3 of tongue, palatine tonsils, oropharynx, middle ear, and pharyngotympanic tube (Eustachian Tube) (Afferent for Gag reflex)

Question 26

What are the 2 motor componets of CN IX that we don't test for?

Answer 26

–Stylopharyngeus muscle –General Visceral Efferents •The Parasympathetic Component that Innervates the Parotid Salivary Gland

Question 27

We do test the sensory portion of CN IX though! How do we do it?

Answer 27

You politely ask to gag your patient to test CN IX and X. It also has taste/ general sensation for posterior 1/3 of the tongue.

Question 28

What would happen with a leasion of CN IX?

Answer 28

–Loss of Gag reflex (interrupted afferent limb, efferent limb is the Vagus Nerve CN X)) –Problem swallowing –Loss of sensation, including taste, from the oropharynx, soft palate, tonsils, posterior 1/3 of tongue, and pharyngeal walls –Loss of carotid sinus reflex (loss of the afferent limb)

Question 29

The vagus (wandering) nerve CN X goes a lot further than the other CNs. What does CN X innervate?

Answer 29

viscera of the neck, thorax, and abdomen

Question 30

CN X exits the brainstem from the medulla and exits the skull via what foramen?

Answer 30

Jugular

Question 31

CN X is both sensory and motor. Where would this wandering nerve have sensory components?

Answer 31

* Sensory from the Aortic Body chemoreceptors * Sensory from the Aortic Arch baroreceptors * Sensory from laryngopharynx, larynx, esophagus, bronchi, lungs, heart, and foregut and midgut abdominal viscera * Sensory from skin posterior to ear and external auditory meatus, and dura in posterior cranial fossa * Taste from the Epiglottis

Question 32

What are the motor components of CN X? Think aboout both parasympathetic and non-parasympathetic.

Answer 32

–Parasympathetic - General Visceral •Efferents: Innervates smooth muscle and glands in the laryngopharynx, larynx, thoracic viscera, and foregut and midgut abdominal viscera –Visceral Motor Efferents - * Mediates swallowing and phonation * Innervates muscles of the Soft Palate (except Tensor Veli Palatini) * Innervates muscles of Pharynx * Innervates the Larynx via the Recurrent Laryngeal Nerves * Is the EFFERENT LIMB OF THE GAG REFLEX - tongue retraction, elevation and constriction of the pharyngeal musculature

Question 33

Name the four muscles, what they do, and what nerve innervates them.

Answer 33

Tensor: Tensor Veli Palatini: V3 - Opens the Eustachian Tube “Pops the ears” Elevator: Levator Veli Palatini X “Ahhhh” muscle Depressor: Palatopharyngeus X Palatoglossus X Elevator of Uvula: Musculus Uvulae X

Question 34

WTF is the musculus Uvulae

Answer 34

Best I could find. I think it is the uvula itself?

Question 35

We make people say Ahh for symmetrical elevation of the soft palate arches, aka. ______ \_\_\_\_\_\_, and Gag them to test CN X(Affernt or Efferent?) What would a deviation to the side indicate? What does hoarseness or Stridor make you think about?

Answer 35

Palatal Reflex Efferent Paralysis of the LEVATOR VELI PALATINI - ipsilateral paralysis of the soft palate and pharynx with damage to CN X Vocal Cord Paralysis - Recurrent Laryngeal N (Gallicurci) Hoarseness is unilateral / Stridor is bilateral (IMMEDIATE ATTENTION)

Question 36

CN X travels throught the ______________ tract before decussation and synapsing in the _________ \_\_\_\_\_\_\_\_\_ and then innervating palatal arches.

Answer 36

corticobulbar tract/ Nucleus ambiguus (Biggus Dickus from Life of Brian)

Question 37

In lab all we can see is a thick nerve because the branches are easily dissected off. After the Inferior Ganglion CN X has 4 branches in the neck, then the recurrent laryngeal nerve. What are those 4 branches?

Answer 37

Pharyngeal Branch Carotid Body Branch Internal/ External Branches of Superior Laryngeal nerve

Question 38

Recurrent Laryngeal N. Left goes under \_\_\_\_\_\_. Right goes under \_\_\_\_\_\_

Answer 38

Left goes under _Aortic Arch_. Right goes under _Right Subclavian Artery_

Question 39

The carotid sinus and aortic arch transmits via CN IX and CN X to the ______ nucleus of the \_\_\_\_\_\_

Answer 39

Solitary nucleus of the medulla

Question 40

CN X caries what kind of information to the solitary nucleus?

Answer 40

Increase or decrease in BP

Question 41

CN __ innervates the carotid sinus/ baro receptors CN __ innervates the aortic carotid/ baro receptors

Answer 41

CN IX CN X

Question 42

If you stimulate the carotidd bodies (caotid sinus massage), you stimulate hypertension. Describe what happens next.

Answer 42

↑ baroreceptor firing → ↑ AV node refractory period → ↓ HR and Cardiac output Travels via CN IX (X for aortic) to the solitary nucleus

Question 43

What is the Cushing reflex/ reaction mediated by the Central Medullary Baroreceptors?

Answer 43

Increased intracranial pressure constricts arterioles, causing cerebral ischemia, reflex hypertension, and reflex bradycardia Mediated by Central Medullary Barorecptors

Question 44

What do Chemoreceptors regulate?

Answer 44

Respiratory activity. CO2 is important for pH

Question 45

You have central and peripheral chemoreceptors. What do each of them sense and where are they?

Answer 45

Central: •Central Medullary Chemoreceptors: sensitive to pH and PCO2, (arterial CO2) _NOT sensitive to PO2_ Peripheral: Carotid body and Aortic arch receptors: respond to low PO2 (\<60 mm Hg), high PCO2, and low blood pH.

Question 46

Spinal Accessory Nerve XI is motor, sensory, or both?

Answer 46

Motor: head and shoulder movements

Question 47

CN XI exits the _____ foramen. The spinal portion arrises from C\_\_ to C\_\_\_

Answer 47

Jugular. C1-C6

Question 48

CN Xi innervates these 2 mm.

Answer 48

Sternoclediomastoid and Trapezius

Question 49

Jugular foramen tumors would impinge what 3 CNs? What kind of tumors would these be?

Answer 49

CN IX, X, and XI Meningiomas and Glomus (Paraganglioma) Tumors. Glomus tumors cells are chemoreceptor cells, similar to the carotid body cells.

Question 50

The last CN! Hypoglossal is CN XII and is (M,S, or B) to the \_\_\_\_\_

Answer 50

Motor to the tongue

Question 51

What are the four muscles of tongue movement and what nerve innervates them?

Answer 51

CN X - Palatoglossus CN XII - Hyoglussus, Genioglossus, Styloglossus

Question 52

We test the integrity by having the pt,. stick out the tongue. It will deviate the the weak side. A LMN lesion will deviate the tongue (toward/away from) the lesion An UMN lession will deviate the tongue (toward/away from) the lesion

Answer 52

Toward LMN (Fasciculations/ atrophy) Away from UMN (Corticobulbar. NO Fasciculations/ atrophy) (Hemiparalysis. Slurred speach with both)

Question 53

What two bones do the root of the tongue attach to?

Answer 53

Mandible and Hyoid Bone

Question 54

The vestibulo-ocular Reflex is tested with the Doll's eyes phoneomena: What is a positive and what does it mean?

Answer 54

Testing CN III, IV, and VIII nuclei in the brainstem. A positive sign would show eye movement opposite head movement and means there is an INTACT brain stem.

Question 55

Brief, intense pain (sharp, stabbing, burning) on one side of the throat that may radiate to the mouth or ear can be caused by what kind of tumor?

Answer 55

Glossopharyngeal Neuralgia - rare Also called Vagoglossopharyngeal Neuralgia

Question 56

Glossopharyngeal Neuralgias can be caused by what?

Answer 56

Vascular impressions on CN IX or CN X or by tumors or rarely Multiple Sclerosis