Lateral vestibulospinal tract

From Wikipedia, the free encyclopedia

Brain: Lateral vestibulospinal tract
Vestibulospinal tract is 2c, in red at bottom center.
Diagram of the principal fasciculi of the spinal cord.

The lateral vestibulospinal tract is one of the descending spinal tracts of the ventromedial pathway.

The lateral part of the vestibulospinal tract is the major portion and is composed of fibers originating in the lateral, superior, and inferior vestibular nuclei (primarily the lateral). It projects ipsilaterally down to the lumbar region of the spinal cord. There it helps to maintain an upright and balanced posture by stimulating extensor motor neurons in the legs. It also innervates muscles of the trunk, thus additionally aiding in body posture. The lateral vestibular nuclei receive input from cerebellum, particularly the vestibulocerebellum, or the flocculi and nodulus. The cerebellum aids in coordinating postural adjustments.

I–VI: Posterior horn	I: Marginal nucleus · II: Substantia gelatinosa of Rolando · III+IV: Nucleus proprius · Spinal lamina V · Spinal lamina VI

VII: Lateral horn	Intermediolateral nucleus · Posterior thoracic nucleus

VIII–IX: Anterior horn	Interneuron · Alpha motor neuron (Onuf's nucleus)

X: Other	Central gelatinous substance · Gray commissure Central canal · Terminal ventricle

White matter

somatic/ ascending (blue)	Posterior/PCML: touch: Gracile · Cuneate Lateral: proprioception: Spinocerebellar (Dorsal, Ventral) · pain/temp: Spinothalamic (Lateral, Anterior) · Posterolateral (Lissauer) · Spinotectal Spinoreticular tract · Spino-olivary tract

motor/ descending (red)	Lateral: Corticospinal (Lateral) · Ep (Rubrospinal, Olivospinal) Anterior: Corticospinal (Anterior) · Ep (Vestibulospinal, Reticulospinal, Tectospinal)

both	Anterior white commissure

External, ventral

Anterior median fissure · Anterolateral sulcus

External, general

Cervical enlargement · Lumbar enlargement · Conus medullaris · Filum terminale · Cauda equina

M: CNS

anat (n/s/m/p/4/e/b/d/c/a/f/l/g)/phys/devp

noco (m/d/e/h/v/s)/cong/tumr, sysi/epon, injr

proc, drug (N1A/2AB/C/3/4/7A/B/C/D)

Human brain, rhombencephalon, metencephalon: pons (TA A14.1.05.101–604, GA 9.785)

Dorsal/
(tegmentum)

Surface

White: Sensory/ascending

MLF, III, IV and VI: Vestibulo-oculomotor fibers

White: Motor/descending

Grey: Cranial nuclei

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

Other grey

Ventral/
(base)

Grey	Pontine nuclei

White: Motor/descending	Corticospinal tract Corticobulbar tract Corticopontine fibers MCP Pontocerebellar fibers

Surface	Basilar sulcus

Other grey: Raphe/
reticular

M: CNS

anat (n/s/m/p/4/e/b/d/c/a/f/l/g)/phys/devp

noco (m/d/e/h/v/s)/cong/tumr, sysi/epon, injr

proc, drug (N1A/2AB/C/3/4/7A/B/C/D)

Brain and spinal cord: neural tracts and fasciculi

Sensory/
ascending

PCML

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

Anterolateral/
pain

Fast/lateral	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)

Slow/medial	1° (Group C nerve fiber → Spinoreticular tract → Reticular formation) → 2° (MD of Thalamus) → 3° (Cingulate cortex)

Motor/
descending

Pyramidal	flexion: Primary motor cortex → Posterior limb of internal capsule → Decussation of pyramids → Corticospinal tract (Lateral, Anterior) → Neuromuscular junction

Extrapyramidal	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

Basal ganglia	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

Cerebellar

Afferent

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

Efferent

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

Bidirectional:
Spinocerebellar

Unc. prop.	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)

Reflex arc	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)

M: CNS

anat (n/s/m/p/4/e/b/d/c/a/f/l/g)/phys/devp

noco (m/d/e/h/v/s)/cong/tumr, sysi/epon, injr

proc, drug (N1A/2AB/C/3/4/7A/B/C/D)

M: PNS

anat (h/r/t/c/b/l/s/a)/phys (r)/devp/prot/nttr/nttm/ntrp

noco/auto/cong/tumr, sysi/epon, injr

proc, drug (N1B)

Auditory and vestibular pathways

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

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

M: EAR

anat (e/p)/phys/devp

noco/cong, epon

proc, drug (S2)

This article is issued from Wikipedia. The text is available under the Creative Commons Attribution/Share Alike; additional terms may apply for the media files.

Lateral vestibulospinal tract

See also