Cranial Nerves, innervations, etc.

Question 1

What are the 4 types of muscle Innervation in the FCP?

Answer 1

1) Bilateral (protective)
2) Unilateral (one-side; not as protective)
3) Ipsilateral (same-side)
4) Contralateral (opposite side)

Question 2

What kind of innervation does CN VII (facial) have for the UPPER FACE? What kind of innervation does it have for the lower face?

Answer 2

Bilateral innervation; Unilateral/Contralateral

Question 3

What kind of Innervation does CN XII (Hypoglossal) have?

Answer 3

Mainly bilateral to all tongue muscles but contralateral to genioglossus muscle.

Question 4

Damage/ lesion to LMN system results in _________?

Answer 4

Weakness, atrophy, fasciculations.

Question 5

Which is the largest of the CNs and what kind of innervation does it have?

Answer 5

CN V (Trigeminal); Bilateral innervation

Question 6

What are the sensory and motor components of CN V (Trigeminal) ?

Answer 6

Sensory= face, mouth, jaw, tongue.
Motor= muscles of mastication, tensor tympani, tensor veli palitini, mylohyoid.

Question 7

What can happen to the jaw if there is a bilateral lesion to the CN V (Trigeminal) versus a unilateral lesion? Which lesion is less likely to affect speech?

Answer 7

Bilateral lesion= jaw hangs open @ rest.
Unilateral lesion= jaw deviates to the weak side.

Unilateral.

Question 8

If a Pt can’t wrinkle his or her forehead, what kind of lesion likely occurred on CN VII (Facial)?

Answer 8

There are probably two lesions (one on each side); since it is bilaterally innervated.

Question 9

CN IX (Glossopharyngeal) has what kind of innervation? Which muscles does it innervate? What does the sensory component include?

Answer 9

Bilateral Innervation;
Innervates Stylopharyngeus muscle of the pharynx.
Sensory component= sends sensory info from pharynx, tongue, and Eustachian tube.

Question 10

What can a lesion to CN IX (Glossopharyngeal) cause?

Answer 10

Decreased gag reflex & reduced pharyngeal sensation.

Question 11

What are the three branches of CN X (Vagus)?

What kind of innervation does CN X (Vagus) have?

Answer 11

1) Pharyngeal Branch
2) Superior Laryngeal Branch
3) Recurrent Laryngeal Branch

Bilateral innervation for all branches.

Question 12

Which muscles does the Pharyngeal branch of CN X (Vagus) innervate?

Answer 12

• All muscles of pharynx (Except stylopharyngeus), -All muscles of soft palate (Except tensor veli palitini),
• Palatoglossus muscle of the tongue.

Question 13

What muscles does the Superior laryngeal branch of CN X (Vagus) innervate?

Answer 13

• Pharyngeal constrictor muscle

- Cricothyroid (CT) muscle

Question 14

What muscles does the Recurrent laryngeal Branch of CN X (Vagus) innervate?

Answer 14

All other intrinsic laryngeal muscles except CT.

Question 15

What kind of innervation does CN XI (Accessory) have?

Answer 15

Bilateral.

Question 16

What is the function of CN XI (Accessory)?

Answer 16

Head and neck movements. Helps Vagus (CN X) innervate the levator palitini to elevate soft palate for VP closure.

Question 17

CN XII (Hypoglossal) innervates which muscles?

Answer 17

All intrinsic and Extrinsic muscles of the tongue except palatoglossus, which is innervated by the pharyngeal branch of Vagus (CN X).

Question 18

T/F The genioglossus muscle is bilaterally innervated by the hypoglossal nerve (CN XII).

Answer 18

False Contralateral.

Question 19

T/F A LMN lesion to CN XII (Hypoglossal) would cause the tongue to deviate to the weak side. It would deviate to the opposite side of lesion.

Answer 19

False; same side of lesion.

Question 20

What are the two control circuits?

Answer 20

1) BG

2) Cerebellum

Question 21

T/F DAP & IAP make up the LMN system.

Answer 21

False; UMN system.

Question 22

T/F IAP is the same as the Pyramidal Tract.

Answer 22

False; Extrapyramidal Tract.

Makes up the UMN system along with the DAP.

Question 23

Damage to the BG can result in which type of dysarthria?

Answer 23

Hyperkinetic or hypokinetic dysarthria.

Question 24

Damage to the cerebellum can result in which type of dysarthria?

Answer 24

Ataxic dysarthria.

Question 25

The balance of which neurotransmitter does the BG depend on for aiding motor activity?

Answer 25

Ach, dopamine, & GABA.

Question 26

What is the function of the BG?

Answer 26

regulating muscle tone, input to the cortex, maintaining normal posture, coordinating motor mvmt.

Question 27

What is the function of the cerebellum?

Answer 27

integrates & coordinates mvmts for speech.
Provides flow and smooth timing for speech.
Size of muscular action.

Question 28

Where does the corticobulbar tract initiate and where does it end?

Answer 28

Originates in the cortex & ends in the brainstem at the level of the CN nuclei.

Question 29

T/F The BG and the cerebellum directly influence the LMN.

Answer 29

False; The IAP, however, does. This is an important distinguishing feature.