Cranial Nerves, innervations, etc. Flashcards
What are the 4 types of muscle Innervation in the FCP?
1) Bilateral (protective)
2) Unilateral (one-side; not as protective)
3) Ipsilateral (same-side)
4) Contralateral (opposite side)
What kind of innervation does CN VII (facial) have for the UPPER FACE? What kind of innervation does it have for the lower face?
Bilateral innervation; Unilateral/Contralateral
What kind of Innervation does CN XII (Hypoglossal) have?
Mainly bilateral to all tongue muscles but contralateral to genioglossus muscle.
Damage/ lesion to LMN system results in _________?
Weakness, atrophy, fasciculations.
Which is the largest of the CNs and what kind of innervation does it have?
CN V (Trigeminal); Bilateral innervation
What are the sensory and motor components of CN V (Trigeminal) ?
Sensory= face, mouth, jaw, tongue. Motor= muscles of mastication, tensor tympani, tensor veli palitini, mylohyoid.
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?
Bilateral lesion= jaw hangs open @ rest.
Unilateral lesion= jaw deviates to the weak side.
Unilateral.
If a Pt can’t wrinkle his or her forehead, what kind of lesion likely occurred on CN VII (Facial)?
There are probably two lesions (one on each side); since it is bilaterally innervated.
CN IX (Glossopharyngeal) has what kind of innervation? Which muscles does it innervate? What does the sensory component include?
Bilateral Innervation;
Innervates Stylopharyngeus muscle of the pharynx.
Sensory component= sends sensory info from pharynx, tongue, and Eustachian tube.
What can a lesion to CN IX (Glossopharyngeal) cause?
Decreased gag reflex & reduced pharyngeal sensation.
What are the three branches of CN X (Vagus)?
What kind of innervation does CN X (Vagus) have?
1) Pharyngeal Branch
2) Superior Laryngeal Branch
3) Recurrent Laryngeal Branch
Bilateral innervation for all branches.
Which muscles does the Pharyngeal branch of CN X (Vagus) innervate?
- All muscles of pharynx (Except stylopharyngeus), -All muscles of soft palate (Except tensor veli palitini),
- Palatoglossus muscle of the tongue.
What muscles does the Superior laryngeal branch of CN X (Vagus) innervate?
- Pharyngeal constrictor muscle
- Cricothyroid (CT) muscle
What muscles does the Recurrent laryngeal Branch of CN X (Vagus) innervate?
All other intrinsic laryngeal muscles except CT.
What kind of innervation does CN XI (Accessory) have?
Bilateral.
What is the function of CN XI (Accessory)?
Head and neck movements. Helps Vagus (CN X) innervate the levator palitini to elevate soft palate for VP closure.
CN XII (Hypoglossal) innervates which muscles?
All intrinsic and Extrinsic muscles of the tongue except palatoglossus, which is innervated by the pharyngeal branch of Vagus (CN X).
T/F The genioglossus muscle is bilaterally innervated by the hypoglossal nerve (CN XII).
False Contralateral.
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.
False; same side of lesion.
What are the two control circuits?
1) BG
2) Cerebellum
T/F DAP & IAP make up the LMN system.
False; UMN system.
T/F IAP is the same as the Pyramidal Tract.
False; Extrapyramidal Tract.
Makes up the UMN system along with the DAP.
Damage to the BG can result in which type of dysarthria?
Hyperkinetic or hypokinetic dysarthria.
Damage to the cerebellum can result in which type of dysarthria?
Ataxic dysarthria.
The balance of which neurotransmitter does the BG depend on for aiding motor activity?
Ach, dopamine, & GABA.
What is the function of the BG?
regulating muscle tone, input to the cortex, maintaining normal posture, coordinating motor mvmt.
What is the function of the cerebellum?
integrates & coordinates mvmts for speech.
Provides flow and smooth timing for speech.
Size of muscular action.
Where does the corticobulbar tract initiate and where does it end?
Originates in the cortex & ends in the brainstem at the level of the CN nuclei.
T/F The BG and the cerebellum directly influence the LMN.
False; The IAP, however, does. This is an important distinguishing feature.
