Anatomy and Physiology of the Vestibulospinal System

nucleus and descends ipsilaterally in the ventrolateral funiculus. It mainly receives input from the oto-lith organs, extends throughout the length of the spinal cord, and exerts excitation on the ex-tensor muscles of the lower leg. Single LVST axons have multiple axon collaterals at different segments along the entire length of the spinal cord, thus playing an important role in maintain-ing the posture. In contrast, the medial vestibulospinal tract (MVST) originates in the descending, medial and lateral vestibular nuclei, and descends bilaterally in the ventromedial funiculus of the cervical cord. It conveys mainly semicircular canal inputs to the neck motoneurons, and single MVST axons have multiple axon collaterals terminating on neck motoneurons in different segments of the cervical spinal cord, thus playing an important role in the vestibulocollic re-flex.