Medial vestibulospinal tract
Tractus vestibulospinalis medialis
A short descending pathway from the medial vestibular nucleus to the cervical spinal cord that steadies the head and links head and eye movements.
At a glance
- English
- Medial vestibulospinal tract
- Latin (TA2)
- Tractus vestibulospinalis medialis
- System
- Nerve
- Region
- Whole body
- Side
- Single, on the midline
About the medial vestibulospinal tract
The medial vestibulospinal tract is the smaller of the two vestibulospinal pathways and belongs to the medial group of descending motor tracts concerned with posture. Most of its fibres come from the medial vestibular nucleus, with some from the inferior vestibular nucleus, in the floor of the fourth ventricle. The fibres project to both sides of the cord.
Leaving the brainstem, the fibres descend within the medial longitudinal fasciculus and continue into the anterior funiculus of the spinal cord, lying close to the anterior median fissure. Unlike the lateral tract, which runs the full length of the cord, this pathway reaches only the cervical and highest thoracic segments. Its fibres end on interneurons and motor neurons of the anterior horn that supply the muscles of the neck, including the cells of the spinal accessory nucleus that serve sternocleidomastoid and trapezius.
The vestibular nuclei also send fibres upwards in the medial longitudinal fasciculus, both directly to the nuclei of the abducens, trochlear and oculomotor nerves and through the paramedian pontine reticular formation. These upward and downward connections together tie the movements of the eyes to those of the head. When the head turns or tilts suddenly, signals from the semicircular canals adjust the neck muscles to steady the head and, at the same time, move both eyes together to hold the gaze on the target.
The tract therefore serves the vestibulocollic reflex, which keeps the head stable in space, and works alongside the vestibulo-ocular reflex. Disease of the medial longitudinal fasciculus, as in multiple sclerosis or brainstem stroke, can disturb this coordination and give rise to double vision and nystagmus.
Course and supply
- Supplies
- Adjusts the neck muscles on both sides in response to head movement, stabilising the head and helping to coordinate head and eye movements.
- Blood supply
- Runs in the anterior funiculus of the cervical cord, supplied by the anterior spinal artery.
Anthromica
See the medial vestibulospinal tract where it really sits, with every layer of the body around it.
- Every layer, one body. Peel from muscle to bone, nerve, vessel and organ, and turn it any way.
- English and Latin. Every structure named the way your exam names it.
- Quiz until it sticks. Short drills on the structures you keep missing.
Free to start. No card.
