Neuroscience Online Logo

Section II: Sensory Systems
11. Vestibular System: Pathways and Reflexes
Part 2 of 2

Lincoln Gray, Ph.D.
.
navigation - see bottom of page for text navigation go back one page Go to the Section II outline Go the the Neuroscience Online home page Index of Terms Go to the next page
divider bar

Lateral and Medial Vestibulospinal Tract

Figure 11.5 shows details of the lateral vestibulospinal tract. As the name suggests, this tract arises in the lateral vestibular nucleus. The tract descends through the inferior vestibular nucleus, giving this nucleus its "salt and pepper" appearance. Below the medulla the lateral vestibulospinal tract descends in the anterior white matter down the entire length of the spinal cord. This tract modulates postural adjustments to movements. For example, the reason we stagger after spinning is due to excess activity in the lateral vestibulospinal tract.

Figure 11.5

The lateral vestibulospinal tract.

1) Pressplayto begin the pathway.
2) Then, click on each layer to see it enlarge with the path showing OR click before playing to see the layer without the path showing.
3) Roll over a layer to identify it's name.

Figure 11.6 shows details of the medial vestibulospinal tract. As its name suggests, this tract starts in the medial vestibular nucleus. It is a bilateral tract. It descends no lower than the mid-thoracic cord. It mediates head position by controlling the muscles of the neck and shoulder.

Figure 11.6

The medial vestibulospinal tract.

1) Pressplayto begin the pathway.
2) Then, click on each layer to see it enlarge with the path showing OR click before playing to see the layer without the path showing.
3) Roll over a layer to identify it's name.

 

Test Your Knowledge
1. The vestibular-occular reflex (VOR) depends on all of the following EXCEPT:

A. trochlear nucleus
B. medial longitudinal fasciculus
C. nystagmus
D. superior vestibular nucleus
E. lateral vestibular nucleus

2. Which descending vestibular pathway is ipsilateral and reaches sacral levels of the spinal cord?

A. lateral vestibular pathway
B. medial vestibular pathway
C. medial longitudinal fasciculus
D. trapezoid body

 

Go back one page Go to next page

Contact the author(s) at: nba_course@uth.tmc.edu
Copyright © 2003-present, All Rights Reserved
The University of Texas Health Science Center at Houston
Created through the Multimedial Scriptorium - Academic Technology