Cranial Nerves

Question 1

From where do cranial nerves receive input?

Answer 1

From the cortex and nuclei in brainstem, exit through foramen. They run together with cranial nerves or cervical nerves.

Question 2

Where do the cranial nerves exit the CNS?

Answer 2

Through the foramen.

Question 3

What other nerves do cranial nerves run with?

Answer 3

They run with other cervical and cranial nerves.

Question 4

where are upper motor neurons located?

Answer 4

cortex

Question 5

How does upper motor neuron damage affect function?

Answer 5

Because there is bilateral input from the cortex, unilateral (damage on one side) damage doesn’t affect function.

Question 6

What is the result of lower motor neuron damage?

Answer 6

paralysis of muscles on the affected side and loss of sense on affected side. Will see the effect unilaterally.

Question 7

What does Cranial Nerve 5 (Trigeminal) provide sensation to?

Answer 7

face, scalp, oral and nasal mucous membrane, teeth, tympanic membrane. Ant 2/3 of tongue

Question 8

What are the branches of CN 5 Trigeminal?

Answer 8

opthalmic, maxillary, Mandibular branch. Top 2/3 are sensory only, lower 1/3 is motor and sensory.

Question 9

Where are lower motor neurons located?

Answer 9

In the brain stem or upper cervical spinal cord. Come out of brainstem and go into muslces on the SAME side.

Question 10

To what muscles does CN 5 provide motor innervation ?

Answer 10

Masseter, ABD, medial pterygoid, lateral pterygoid, mylohyoid, temporalis, tensor veli palatini, tensor tympani

Question 11

What are the the motor branches of CN 7?

Answer 11

There are 5 motor branches: temporal, zygomatic, buccal, mandibular, cervical.

Question 12

To what muscles does CN 7 (Facial) provide motor innervation?

Answer 12

Motor control to all face muscles (frontalis, orbicularis oris, buccinator, etc.) Stylohyoid, posterior belly of digastric, stapedius

Question 13

To what structures does CN 7 provide Taste innervation?

Answer 13

TASTE anterior 2/3 of tongue, floor of mouth, palate

Question 14

To what structures does CN 7 provide Visceral Motor innervation?

Answer 14

PARASYMPATHETIC innervation of submandibular and sublingual gland, lacrimal gland, glands to nose and hard and soft palate

Question 15

What is the Chorda Tympani of CN 7?

Answer 15

portion of facial nerve that provides taste to anterior 2/3 of tongue and submandibular and sublingual glands.
Rides on lingual nerve of CN 5 mandibular branch whcih gives general

Question 16

What does upper motor neuron damage look like for the CN 7?

Answer 16

paralyiss of only LOWER facial muscles on CONTRALATERAL side. Emotionally motivated may still remain

Question 17

What does CN7 lower motor neuron damage look like?

Answer 17

Paralysis of all muscles on affected side. Loss of sense on affected

Question 18

Where is the lesion on CN7 if there is normal facial muscle function but loss of sensation?

Answer 18

Normal facial muscle function but loss of general tongue sense, lesion after chorda tympani leaves main nerve, but while it’s still with lingual nerve

Question 19

Where is the lesion on CN7 if there is abnormal facial muscle function?

Answer 19

If abnormal facial muscle function, lesion is before nerve leaves the facial canal.

Question 20

What muscle does CN 9 (Glossopharyngeal) provide motor innervation to?

Answer 20

Stylopharyngeus

Question 21

What stuctures does CN 9 (Glossopharygeal) provide Sensory innervation?

Answer 21

posterior 1/3 of tongue, tonsils, skin of external ear, internal surface tympanic membrane, PHARYNX

Question 22

What structures does CN9 provide Special Sensory innervation to?

Answer 22

Taste to posterior 1/3 of tongue

Question 23

CN 9 Glossopharngeal Visceral

Answer 23

Stimulates parotid gland

Question 24

CN9 Glossopharyngeal Visceral Sensory

Answer 24

provides subconsious sensation from carotid body and carotid sinus.

Question 25

Carotid body

Answer 25

chemoreceptor that monitors O2 in blood. Less O2=increase in rate and depth of breathing

Question 26

Carotid sinus

Answer 26

Baroreceptor. Monitors change in arterial blood pressure

Question 27

CN9 Damage

Answer 27

Seldom isolated lesion, since closely associated with 10 and 11.

Question 28

CN 10 Vagus branches

Answer 28

3 branches: Pharyngeal, Superior laryngeal nerve, recurrent laryngeal nerve

Question 29

CN 10 Pharyngeal branch Motor

Answer 29

pharyngeal constrictors, levator veli palatini, salpingopharyngeus, palatopharyngeus, palatoglossus

Question 30

CN10 Pharyngeal Branch Sensory

Answer 30

Gneral sense to pharynx.

Question 31

CN 10 Pharyngeal Branch Visceral

Answer 31

Pharyngeal mucosa- control secretion

Question 32

CN 10 Superior Laryngeal Nerve

Answer 32

Internal laryngeal= general and visceral sensory from base of tongue, epiglottis, aryepiglottic folds, and larynx to level of vocal folds.

Question 33

CN 10 Superior laryngeal nerve motor functions

Answer 33

External laryngeal nerve provides motor to inferior constrictor and cricothyroid.

Question 34

CN 10 Recurrent Laryngeal Nerve

Answer 34

Motor to the intrinsic muscles of the larynx (except the cricothyroid). Provides general and visceral sensation from the vocal folds and the larynx below the level of vocal folds.

Question 35

Right side path of recurrent laryngeal nerve

Answer 35

divides off vagus, hooks under SUBCLAVIAN artery, and ascends back to the larynx

Question 36

Left side path of recurrent laryngeal nerve

Answer 36

divides off vagus, hooks under the aortic arch, and ascends back to the larynx

Question 37

What does CN 10 provide General Visceral sensation to? and Motor

Answer 37

provides motor and visceral sensation to lungs-bronchioconstriction esophogeal branches- speeds up persistalsis by acting on smooth muscles. Stimulates secretion of gastric glands for emptying stomach.

Question 38

What are the two portions of Cranial Nerve 11 Accessory?

Answer 38

2 portions: cranial root and spinal root

Question 39

What does the cranial root of CN 11 do?

Answer 39

joins pharyngeal branch of CN 10 to form pharyngeal plexus. Innervates with pharyngeal branch of CN10. At times considered part of CN 10

Question 40

What does the Spinal root of CN 11 do?

Answer 40

motor to sternocleidomastoid and trapezius

Question 41

What structures doe CN 12 Hypoglossal provide motor innervation to?

Answer 41

Motor: all intrinsic and extrinsic muscles of tongue except palatoglossus (CN10)

Question 42

What does upper motor neuron damage to CN 12 Hypoglossal result in?

Answer 42

contralateral side affected, tongue deviates to opposite side from lesion.

Question 43

What does lower motor neuron damage to CN 12 result in?

Answer 43

Ipsilateral side affected, tongue deviates toward side of lesion.

Question 44

What moto nuclei are housed in the Pons?

Answer 44

house motor nuceli for 5 and 7

Question 45

What moto nuclei are housed in the Medulla

Answer 45

CN 9, 10, cranial root 11, 12

Question 46

What is housed in Cervical Spine C1-C5 or 6?

Answer 46

Spinal root of CN 11

Question 47

What is the Reticular formation?

Answer 47

central part of brainstem (medulla and pons). | The nuclei within interact with cranial nerves.

Question 48

What Nuclei are within reticular formation?

Answer 48

nucleus ambiguus, salivary nuclei, nucleus of tractus solitarius

Question 49

What is the function of the Nucleus ambiguus

Answer 49

Motor nuclei, interacts with 9, 10, 11.

Question 50

What is Salivary nuceli

Answer 50

Motor nuclei, above nucleus ambiguous, interacts with CN 7 and 9

Question 51

What is the nucleus of tractus solitarius

Answer 51

VIsceral sensory nuclei. Recieves fibers from CN 7, 9, 10