Cranial Nerve Pathway

Question 1

Hypoglossal (XII) Nucleus
- Lower Medulla
- Middle Medulla

Answer 1

Function:
- Ipsi. motor control of tongue

Input:
- ipsi. descending from the cerebral cortex

Output:
- ipsi. tongue muscles – CN XII

Question 2

Ambiguous Nuclei (IX - XI)
- Lower Medulla
- Middle Medulla

Answer 2

Function:
- ipsi motor control of larynx and pharynx

Input:
- descending motor tracts from cerebral cortex

Output:
- Muscles of larynx and pharynx – CN IX-CN XI

Question 3

Spinal Trigeminal (V) equivalent to spinothalamic tract
- Lower Medulla
- Middle Medulla

Answer 3

Function:
- ipsi pain and temp from head

Input:
- ipsi peripheral receptors for pain and temperature

Output:
- contra. Ventral Posteromedial (VPM) nucleus of thalamus

Question 4

Medial Longitudinal Fasciculus (Medial Vestibulospinal tract)
- Lower Medulla
- Upper Medulla
- Lower Pons

• *Middle Pons
• *Upper Pons/Lower Midbrain

Answer 4

Function:
- Balance and Posture

Input:
- Brainstem & Ipsi. Medial Vestibular Nucleus

Output:
- motor neurons in spinal cord

*Function:
- Eye movements, balance

*Input:
- abducens and ipsi medial vestibular nucleus

*Output:
- oculomotor, motor neurons in spinal cord

Question 5

Tectospinal Tract
- Lower Medulla
- Upper Medulla
- Lower Pons

Answer 5

Function:
- Contra. reflex postural movement

Input:
- ipsi. tectum (superior colliculus)

Output:
- contra. motor neurons in spinal cord

Question 6

Dorsal Efferent Nucleus of the Vagus (X) Tract
- Middle Medulla

Answer 6

Function:
- ipsi. parasympathetic innervation to thoracic and abdominal viscera

Input:
- Bilateral hypothalamus, reticular formation

Output:
- ipsi. thru CN X to thoracic and abdominal viscera

Question 7

Solitary (VII, IX, X) Tract
- Middle Medulla

Answer 7

Function:
- ipsi. taste

Input:
- ipsi. taste buds thru CNs VII, IX, X

Output:
- ipsi VPM of thalamus

Question 8

Vestibular Nuclei (Middle and Inferior VIII)
- Middle Medulla

Answer 8

Function:
- balance and posture

Input:
- ipsi CN VIII from inner ear

Output:
- Medial Longitudinal fasciculus

Question 9

X and XII Nerves (Tract)
- Middle Medulla

Answer 9

Function:
- X - parasympathetic supply to thorax, abdomen, muscles of throat
- XII - muscles under tongue

Input:
- X - dorsal efferent nucleus of vagus
- XII - hypoglossal nucleus of medulla

Output:
- X - thorax, abdomen viscera
- XII - muscles of tongue

Question 10

Cochlear Nuclei (Dorsal and Ventral, VIII)
- Upper Medulla

Answer 10

Function:
- ipsi. hearing

Input:
- ipsi. CN VIII from spiral ganglia

Output:
- Bilateral superior olivary nuclei, inferior colliculus via lateral lemniscus

Question 11

Vestibular Nuclei (inferior and medial VIII)
- Upper Medulla

Answer 11

Function:
- balance and posture

Input:
- ipsi. CN VIII from inner ear

Output:
- Medial longitudinal fasciculus

Question 12

Spinal Trigeminal (V) Nuclei
- Upper Medulla

Answer 12

Function:
- ipsi. pain and temp of head

Input:
- ipsi peripheral receptors for pain and temperature

Output:
- contra (VPM) of thalamus

Question 13

CN VI, VII, VIII - LR6SO4
- Upper Medulla Tract
- Lower Pons - VI and VII

Answer 13

Function:
- VI - lateral rectus moving laterally, abducts

• VII - facial expression, ipsi. motor control facial muscles
• VIII - balance and hearing

Input:
- VI - abducens nucleus in pons

• VII - facial motor nucleus of pons
• VIII - vestibular organs inner ear

Output:
- VI - lateral rectus

• VII - Facial muscles
• VIII - vestibular nuclei of medulla

Question 14

Superior Olivary Nucleus
- Lower Pons

Answer 14

Function:
- Auditory Pathway

Input:
- bilateral cochlear nuclei

Output:
- bilateral inferior colliculus, thru lateral lemniscus

Question 15

Lateral Lemniscus Tract
- Lower Pons
- Middle Pons
- Upper Pons/Lower Midbrain

Answer 15

Function:
- hearing

Input:
- contra. cochlear nucleus and ipsi. superior olivary nucleus

Output:
- inferior colliculus

Question 16

Principal MOTOR of Nucleus of V
- Middle Pons

Answer 16

Function:
- control muscles of chewing

Input:
- ipsi. descending motor tracts

Output:
- ipsi. jaw muscles

Question 17

Mesencephalic Nucleus of V
- Middle Pons

Answer 17

Function:
- proprioceptive info. from jaw muscles

Input:
- proprioceptors in jaw muscles

Output:
- jaw muscles for a reflex arc and cerebellum

Question 17

Principal SENSORY Nucleus of V
- Middle Pons

Answer 17

Function:
- Tactile & proprioception from face

Input:
- peripheral receptors for touch and proprioception

Output:
- VPM of thalamus

Question 18

Trigeminothalamic Tract
- middle Pons
- Upper Pons/Lower Midbrain
- Upper Midbrain

Answer 18

Function:
- somatosensory (head), tactile & proprioception

Input:
- principal sensory nucleus of trigeminal

Output:
- VPM of thalamus

Question 19

Inferior Colliculus Nuclei
- Upper Pons/Lower Midbrain

Answer 19

Function;
- hearing

Input:
- cochlear nucleus and superior olivary nucleus

Output:
- medial geniculate body

Question 20

Trochlear (IV) Nuclei
- Upper Pons/Lower Midbrain

Answer 20

Function:
- Innervates superior oblique

Input:
- medial longitudinal fasciculus

Output:
- CN IV nerve fibers to contra. superior oblique

Question 21

Brachium of the Inferior Colliculus
- Upper Pons/Lower Midbrain Tract
- Upper Midbrain

Answer 21

Function:
- Hearing

Input:
- inferior colliculus

Output:
- medial geniculate

Question 22

Superior Colliculus (II) Nucleus
- Upper Midbrain

Answer 22

Function:
- visual motor integration, helps to coordinate saccadic and other eye movements

Input:
- retina and ipsi striate cortex

Output:
- ipsi. tectospinal tract

Question 23

Oculomotor (III) Nucleus
- Upper Midbrain

Answer 23

Function:
- eye movement

Input:
- Medial Longitudinal fasciculus

Output:
- ciliary ganglion or respective muscles

Question 24

Edinger- Westphal
- Upper Midbrain

Answer 24

Function:
- parasympathetic input to eye

Input:
- reticular formation

Output:
- iris sphincter

Question 25

Medial Geniculate Nucleus
- Upper Midbrain

Answer 25

Function:
- auditory

Input;
- inferior colliculus through brachium of inferior colliculus

Output:
- auditory cortex

Question 26

CN III (tract)
- Upper Midbrain

Answer 26

Function:
- motor control of eyes and eyelids

Input:
- MLF fibers, CN III Nucleus

Output:
- VPM of Thalamus