Lab 9 - Descending Pathways to the Spinal Cord

Vestibulospinal Pathways - Medulla

Figure 1 is a transverse section through the rostral medulla. At this level of the medulla, the nucleus of origin of the lateral vestibulospinal tract, the lateral vestibular nucleus, is no longer present. The lateral vestibulospinal tract (uncrossed fibers) are descending along the anterior margin of the inferior vestibular nucleus. The medial vestibular nucleus continues to send axons into the medial longitudinal fasciculus, some of which descend as the medial vestibulospinal tract.

Figure 2 is a transverse section at the caudal medulla. The lateral vestibulospinal tract, medial longitudinal fasciculus and tectospinal tract are shifted anteriorly by the pyramidal decussation. Notice that the fiber tracts that will form the anterior funiculus of the spinal cord are, at this level, located in the anterior-medial region of the medulla.