Cranial Nerve Pathway Flashcards
Hypoglossal (XII) Nucleus
- Lower Medulla
- Middle Medulla
Function:
- Ipsi. motor control of tongue
Input:
- ipsi. descending from the cerebral cortex
Output:
- ipsi. tongue muscles – CN XII
Ambiguous Nuclei (IX - XI)
- Lower Medulla
- Middle Medulla
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
Spinal Trigeminal (V) equivalent to spinothalamic tract
- Lower Medulla
- Middle Medulla
Function:
- ipsi pain and temp from head
Input:
- ipsi peripheral receptors for pain and temperature
Output:
- contra. Ventral Posteromedial (VPM) nucleus of thalamus
Medial Longitudinal Fasciculus (Medial Vestibulospinal tract)
- Lower Medulla
- Upper Medulla
- Lower Pons
- *Middle Pons
- *Upper Pons/Lower Midbrain
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
Tectospinal Tract
- Lower Medulla
- Upper Medulla
- Lower Pons
Function:
- Contra. reflex postural movement
Input:
- ipsi. tectum (superior colliculus)
Output:
- contra. motor neurons in spinal cord
Dorsal Efferent Nucleus of the Vagus (X) Tract
- Middle Medulla
Function:
- ipsi. parasympathetic innervation to thoracic and abdominal viscera
Input:
- Bilateral hypothalamus, reticular formation
Output:
- ipsi. thru CN X to thoracic and abdominal viscera
Solitary (VII, IX, X) Tract
- Middle Medulla
Function:
- ipsi. taste
Input:
- ipsi. taste buds thru CNs VII, IX, X
Output:
- ipsi VPM of thalamus
Vestibular Nuclei (Middle and Inferior VIII)
- Middle Medulla
Function:
- balance and posture
Input:
- ipsi CN VIII from inner ear
Output:
- Medial Longitudinal fasciculus
X and XII Nerves (Tract)
- Middle Medulla
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
Cochlear Nuclei (Dorsal and Ventral, VIII)
- Upper Medulla
Function:
- ipsi. hearing
Input:
- ipsi. CN VIII from spiral ganglia
Output:
- Bilateral superior olivary nuclei, inferior colliculus via lateral lemniscus
Vestibular Nuclei (inferior and medial VIII)
- Upper Medulla
Function:
- balance and posture
Input:
- ipsi. CN VIII from inner ear
Output:
- Medial longitudinal fasciculus
Spinal Trigeminal (V) Nuclei
- Upper Medulla
Function:
- ipsi. pain and temp of head
Input:
- ipsi peripheral receptors for pain and temperature
Output:
- contra (VPM) of thalamus
CN VI, VII, VIII - LR6SO4
- Upper Medulla Tract
- Lower Pons - VI and VII
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
Superior Olivary Nucleus
- Lower Pons
Function:
- Auditory Pathway
Input:
- bilateral cochlear nuclei
Output:
- bilateral inferior colliculus, thru lateral lemniscus
Lateral Lemniscus Tract
- Lower Pons
- Middle Pons
- Upper Pons/Lower Midbrain
Function:
- hearing
Input:
- contra. cochlear nucleus and ipsi. superior olivary nucleus
Output:
- inferior colliculus
Principal MOTOR of Nucleus of V
- Middle Pons
Function:
- control muscles of chewing
Input:
- ipsi. descending motor tracts
Output:
- ipsi. jaw muscles
Mesencephalic Nucleus of V
- Middle Pons
Function:
- proprioceptive info. from jaw muscles
Input:
- proprioceptors in jaw muscles
Output:
- jaw muscles for a reflex arc and cerebellum
Principal SENSORY Nucleus of V
- Middle Pons
Function:
- Tactile & proprioception from face
Input:
- peripheral receptors for touch and proprioception
Output:
- VPM of thalamus
Trigeminothalamic Tract
- middle Pons
- Upper Pons/Lower Midbrain
- Upper Midbrain
Function:
- somatosensory (head), tactile & proprioception
Input:
- principal sensory nucleus of trigeminal
Output:
- VPM of thalamus
Inferior Colliculus Nuclei
- Upper Pons/Lower Midbrain
Function;
- hearing
Input:
- cochlear nucleus and superior olivary nucleus
Output:
- medial geniculate body
Trochlear (IV) Nuclei
- Upper Pons/Lower Midbrain
Function:
- Innervates superior oblique
Input:
- medial longitudinal fasciculus
Output:
- CN IV nerve fibers to contra. superior oblique
Brachium of the Inferior Colliculus
- Upper Pons/Lower Midbrain Tract
- Upper Midbrain
Function:
- Hearing
Input:
- inferior colliculus
Output:
- medial geniculate
Superior Colliculus (II) Nucleus
- Upper Midbrain
Function:
- visual motor integration, helps to coordinate saccadic and other eye movements
Input:
- retina and ipsi striate cortex
Output:
- ipsi. tectospinal tract
Oculomotor (III) Nucleus
- Upper Midbrain
Function:
- eye movement
Input:
- Medial Longitudinal fasciculus
Output:
- ciliary ganglion or respective muscles
