VPB 121: Veterinary Physiology - II (2+1)

VESTIBULO SPINAL TRACT

• Consists of two descending fiber tracts :
  • Vestibulospinal tract and
  • Medial longitudinal fasciculus.
• Oringinates from the lateral vestibular nucleus and descends ipsilaterally through th length of the spinal cord.
• Medial longitudinal fasciculus fibres terminate monosynaptically upon alpha motor neurons.
• The tract ipsilaterally exerts an excitatory influence upon extensor muscle tone and an inhibitory influence upon flexor muscle tone and contralaterally exerts an inhibitory influence upon extensor muscle tone and an inhibitory influence on flexor muscle tone.
• Also alters the tonus of the muscles of neck and forelimb.
• Exert considerable influence upon the ANS  by the production of motion sickness involving the constant acceleration and deceleration of the head.