Cranial Nerves

Question 1

What innervates facial muscles?

Answer 1

Corticobulbar tract: facial nerve (CN7)
-this does upper and lower face

Extra tract
-this does upper face

So upper face is spared in UMN motor cortex lesion

Question 2

Lesion in optic nerve

Answer 2

Monocular vision loss

Question 3

Lesion at optic chiasm

Answer 3

Bitemporal hemianopsia

Question 4

Lesion in optic tract

Answer 4

Homonymous hemianopia (or quadrant)

Question 5

What muscles does the occulomotor nerve innervate?

Answer 5

Levator palpebrae superioris
Superior rectus muscle
Pupil constrictor muscles
Medial rectus
Inferior oblique

Functions: upward gaze, adduction gaze, downward gaze, extorsion

Question 6

Trochlear nerve

Answer 6

Innervate superior oblique muscle: downward gaze and intorsion

Unique as comes off posterior midbrain

Question 7

Trigeminal nerve

Answer 7

Facial sensation
Tears
Masseter and temporalis muscles
Blink reflex

Question 8

Abducens nerve

Answer 8

Lateral rectus muscle of eye: eye adduction

Nuclei in pons

Question 9

Facial nerve

Answer 9

Anterior two thirds of tongue: taste
Motor to facial muscles
Motor to stapidius muscle
Parasympathetic innervation of lacrimal and salivary glands

Lower motor neuron lesion will get whole face, upper motor neuron lesion will get lower face

Question 10

Glossopharyngeal nerve

Answer 10

Taste: posterior third of tongue
Uvula, palate
Pain in upper mouth (brain freeze)
Gag reflex
Chemoreceptors on carotid body 
Parotid gland stimulation