Lab 5 - Somatosensory, Viscerosensory and Spinocerebellar Pathways

Overview - Spinothalamic Pathways

The figure shows the course of the spinothalamic tract from the spinal cord to the midbrain. In the spinal cord this tract is located in the lateral funiculus. Overview - Spinothalamic PathwaysIn the caudal medulla, the tract continues in its midlateral position. When you start seeing the inferior olivary nucleus (purple in the figure) in the mid medulla, you can easily locate the spinothalamic tract slightly posterior to it. In the pons and midbrain the tract can be located by its posterolateral association with the medial lemniscus. Finally, the inset shows a cut through the diencephalon. Recall that the 2° neospinothalamic fibers terminate in the ventral posterolateral thalamic nuclei (VPL), while the 3° paleospinothalamic fibers find themselves in the intralaminar nuclei of the thalamus, which consist of the centromedial thalamic nuclei (CM) and the Nucleus parafascicularis (PF). The organization of the thalamic nuclei will be covered in more detail in future labs.

In the next section we will go through more sections of the spinal cord and brainstem. Make sure you understand these relationships before you move on.