The medial vestibulospinal tract is one of the descending spinal tracts of the ventromedial pathway.
The medial part of the vestibulospinal tract is the smaller part, and is primarily made of fibers from the medial vestibular nucleus. It projects bilaterally down the spinal cord and triggers the ventral horn of the cervical spinal circuits, particularly controlling lower motor neurons associated with the spinal accessory nerve (CN XI). Additionally, the pathway projects superiorly to the paramedian pontine reticular formation, indirectly innervating the nuclei of CN VI and III. Through this superior projection, the medial vestibulospinal tract is involved in "yoking" the eyes together in response to rapid movement of the head. Thus, cumulatively it controls position of the head, neck, and eyes in response to changes in posture.
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Anatomy of torso (primarily): the spinal cord (TA 14.1.02, GA 9.749)
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| External, dorsal |
Posterior median sulcus · Posterolateral sulcus
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Grey matter/
Rexed laminae |
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I–VI: Posterior horn
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I: Marginal nucleus · II: Substantia gelatinosa of Rolando · III+IV: Nucleus proprius · Spinal lamina V · Spinal lamina VI
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VII: Lateral horn
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Intermediolateral nucleus · Posterior thoracic nucleus
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VIII–IX: Anterior horn
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Interneuron · Alpha motor neuron (Onuf's nucleus)
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X: Other
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Central gelatinous substance · Gray commissure
Central canal · Terminal ventricle
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| White matter |
somatic/
ascending
(blue)
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Posterior/PCML: touch: Gracile · Cuneate
Lateral: proprioception: Spinocerebellar (Dorsal, Ventral) · pain/temp: Spinothalamic (Lateral, Anterior) · Posterolateral (Lissauer) · Spinotectal
Spinoreticular tract · Spino-olivary tract
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motor/
descending
(red)
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Lateral: Corticospinal (Lateral) · Ep (Rubrospinal, Olivospinal)
Anterior: Corticospinal (Anterior) · Ep (Vestibulospinal, Reticulospinal, Tectospinal)
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both
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Anterior white commissure
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| External, ventral |
Anterior median fissure · Anterolateral sulcus
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| External, general |
Cervical enlargement · Lumbar enlargement · Conus medullaris · Filum terminale · Cauda equina
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M: CNS
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anat (n/s/m/p/4/e/b/d/c/a/f/l/g)/phys/devp
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noco (m/d/e/h/v/s)/cong/tumr, sysi/epon, injr
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proc, drug (N1A/2AB/C/3/4/7A/B/C/D)
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Human brain, rhombencephalon, metencephalon: pons (TA A14.1.05.101–604, GA 9.785)
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Dorsal/
(tegmentum) |
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Surface
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Cerebellopontine angle · Superior medullary velum · Sulcus limitans · Medial eminence · Facial colliculus
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White: Sensory/ascending
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Trapezoid body/VIII · Trigeminal lemniscus (Dorsal trigeminal tract, Ventral trigeminal tract) · Medial lemniscus · Lateral lemniscus
MLF, III, IV and VI: Vestibulo-oculomotor fibers
Anterior trigeminothalamic tract · Central tegmental tract
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White: Motor/descending
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ICP (Vestibulocerebellar tract)
MLF, III, IV and VI: Vestibulospinal tract (Medial vestibulospinal tract, Lateral vestibulospinal tract)
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Grey: Cranial nuclei
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afferent: GSA: Principal V/Spinal V · VIII-c (Dorsal, Anterior)/VIII-v (Superior)
efferent: SVE: Motor V · VII · GSE: VI · GVE: VII: Superior salivary nucleus
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Other grey
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Apneustic center · Pneumotaxic center (Medial parabrachial nucleus) · Lateral parabrachial nucleus · Superior olivary nucleus · Caerulean nucleus
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Ventral/
(base) |
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Grey
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Pontine nuclei
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White: Motor/descending
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Corticospinal tract · Corticobulbar tract · Corticopontine fibers
MCP (Pontocerebellar fibers)
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Surface
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Basilar sulcus
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Other grey: Raphe/
reticular |
Reticular formation (Caudal, Oral, Tegmental, Paramedian) · Raphe nuclei (Median)
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M: CNS
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anat (n/s/m/p/4/e/b/d/c/a/f/l/g)/phys/devp
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noco (m/d/e/h/v/s)/cong/tumr, sysi/epon, injr
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proc, drug (N1A/2AB/C/3/4/7A/B/C/D)
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Brain and spinal cord: neural tracts and fasciculi
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Sensory/
ascending |
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PCML
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1°: Pacinian corpuscle/Meissner's corpuscle → Posterior column (Gracile fasciculus/Cuneate fasciculus) → Gracile nucleus/Cuneate nucleus
2°: → sensory decussation/arcuate fibers (Posterior external arcuate fibers, Internal arcuate fibers) → Medial lemniscus/Trigeminal lemniscus → Thalamus (VPL, VPM)
3°: → Posterior limb of internal capsule → Postcentral gyrus
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Anterolateral/
pain
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Fast/lateral
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1° (Free nerve ending → A delta fiber) → 2° (Anterior white commissure → Lateral and Anterior Spinothalamic tract → Spinal lemniscus → VPL of Thalamus) → 3° (Postcentral gyrus) → 4° (Posterior parietal cortex)
2° (Spinotectal tract → Superior colliculus of Midbrain tectum)
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Slow/medial
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1° (Group C nerve fiber → Spinoreticular tract → Reticular formation) → 2° (MD of Thalamus) → 3° (Cingulate cortex)
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Motor/
descending |
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Pyramidal
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flexion: Primary motor cortex → Posterior limb of internal capsule → Decussation of pyramids → Corticospinal tract (Lateral, Anterior) → Neuromuscular junction
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Extrapyramidal
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flexion: Primary motor cortex → Genu of internal capsule → Corticobulbar tract → Facial motor nucleus → Facial muscles
flexion: Red nucleus → Rubrospinal tract
extension: Vestibulocerebellum → Vestibular nuclei → Vestibulospinal tract
extension: Vestibulocerebellum → Reticular formation → Reticulospinal tract
Midbrain tectum → Tectospinal tract → muscles of neck
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Basal ganglia
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direct: 1° (Motor cortex → Striatum) → 2° (GPi) → 3° (Lenticular fasciculus/Ansa lenticularis → Thalamic fasciculus → VL of Thalamus) → 4° (Thalamocortical radiations → Supplementary motor area) → 5° (Motor cortex)
indirect: 1° (Motor cortex → Striatum) → 2° (GPe) → 3° (Subthalamic fasciculus → Subthalamic nucleus) → 4° (Subthalamic fasciculus → GPi) → 5° (Lenticular fasciculus/Ansa lenticularis → Thalamic fasciculus → VL of Thalamus) → 6° (Thalamocortical radiations → Supplementary motor area) → 7° (Motor cortex)
nigrostriatal pathway: Pars compacta → Striatum
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| Cerebellar |
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Afferent
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Vestibular nucleus → Vestibulocerebellar tract → ICP → Cerebellum → Granule cell
Pontine nuclei → Pontocerebellar fibers → MCP → Deep cerebellar nuclei → Granule cell
Inferior olivary nucleus → Olivocerebellar tract → ICP → Hemisphere → Purkinje cell → Deep cerebellar nuclei
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Efferent
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Dentate nucleus in Lateral hemisphere/pontocerebellum → SCP → Dentatothalamic tract → Thalamus (VL) → Motor cortex
Interposed nucleus in Intermediate hemisphere/spinocerebellum → SCP → Reticular formation, or → Cerebellothalamic tract → Red nucleus → Thalamus (VL) → Motor cortex
Fastigial nucleus in Flocculonodular lobe/vestibulocerebellum → Vestibulocerebellar tract → Vestibular nucleus
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Bidirectional:
Spinocerebellar
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Unc. prop.
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lower limb → 1° (muscle spindles → DRG) → 2° (Posterior thoracic nucleus → Dorsal/posterior spinocerebellar tract → ICP → Cerebellar vermis)
upper limb → 1° (muscle spindles → DRG) → 2° (Accessory cuneate nucleus → Cuneocerebellar tract → ICP → Anterior lobe of cerebellum)
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Reflex arc
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lower limb → 1° (Golgi tendon organ) → 2° (Ventral/anterior spinocerebellar tract→ SCP → Cerebellar vermis)
upper limb → 1° (Golgi tendon organ) → 2° (Rostral spinocerebellar tract → ICP → Cerebellum)
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M: CNS
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anat (n/s/m/p/4/e/b/d/c/a/f/l/g)/phys/devp
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noco (m/d/e/h/v/s)/cong/tumr, sysi/epon, injr
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proc, drug (N1A/2AB/C/3/4/7A/B/C/D)
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M: PNS
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anat (h/r/t/c/b/l/s/a)/phys (r)/devp/prot/nttr/nttm/ntrp
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noco/auto/cong/tumr, sysi/epon, injr
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proc, drug (N1B)
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Auditory and vestibular pathways
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| Auditory |
- inner ear: Hair cells → Spiral ganglion → Cochlear nerve VIII →
- pons: Cochlear nuclei (Anterior, Dorsal) → Trapezoid body → Superior olivary nuclei →
- midbrain: Lateral lemniscus → Inferior colliculi →
- thalamus: Medial geniculate nuclei →
- cerebrum: Acoustic radiation → Primary auditory cortex
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| Vestibular |
- inner ear: Vestibular nerve VIII →
- pons: Vestibular nuclei (Medial vestibular nucleus, Lateral vestibular nucleus)
- cerebellum: Flocculonodular lobe
- spinal cord: Vestibulospinal tract (Medial vestibulospinal tract, Lateral vestibulospinal tract)
- thalamus: Ventral posterolateral nucleus
- cerebrum: Vestibular cortex
- Vestibulo-oculomotor fibers
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M: EAR
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anat (e/p)/phys/devp
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noco/cong, epon
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proc, drug (S2)
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