Brainstem and Cranial Nerve Nuclei

Question 1

List the somatic motor cranial nerve nuclei and their function

Answer 1

• oculomotor (III)
• trochlear (IV)
• abducens (VI)
• hypoglossal (XII)

Drive eye and tongue muscles

Question 2

List the special visceral motor cranial nerve nuclei and their function

Answer 2

• trigeminal (V) = chew
• facial (VII) = grimace
• glossopharyngeal (IX) = swallow
• vagus (X) = speak
• accessory (XI) = shrug

Question 3

List the autonomic motor cranial nerve nuclei

Answer 3

• oculomotor (III): Edinger-Westphal
• facial (VII): superior salivatory
• glossopharyngeal (IX): inferior salivatory
• vagus (X): dorsal

Question 4

List the somatic sensory cranial nerve nuclei and their function

Answer 4

• trigeminal spinal (V) = pain, temp, touch
• trigeminal principal (V) = vibration, light touch
• trigeminal mesencephalic (V) = proprioception, jaw jerk

Question 5

List the special somatic sensory cranial nerve nuclei

Answer 5

• optic (II)

- vestibulocochlear (VIII)

Question 6

List the visceral sensory cranial nerve nuclei

Answer 6

• facial (VII)
• glossopharyngeal (IX)
• vagus (X)

Question 7

Briefly describe the corticobulbar tracts

Answer 7

• begin in lateral part of motor cortex
• information passes through internal capsule to brainstem
• goes to motor nuclei, decussating at the level of the nucleus
• supplies musculature of the head and neck

Question 8

What are the signs of a lesion affecting cranial nerve function?

Answer 8

• eye muscle weakness
• loss of face sensation
• problems speaking, swallowing
• vertigo
• changes in taste/hearing