Answer: Lissauer’s tract is a white matter tract in the spinal cord that projects up or down across one or two spinal segments.
Somatosensory information arising from the skin enters into the spinal cord via the dorsal horn. From here, it can ascend into the thalamus. Some of those fibers ascend or descend locally, across one or two spinal segments. The white matter bundles that only project within the spinal cord are called Lissauer’s tract, or the posterolateral tract. These axons mostly carry crude touch and pressure information.
The spinal cord is divided into five main regions. From anterior to posterior (neck to leg) they are cervical, thoracic, lumbar, and sacral. Lissauer’s tract fibers are most developed among the upper cervical segments of the spinal column.
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