Lateral spinothalamic tract

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The lateral spinothalamic tract (or lateral spinothalamic fasciculus) is a bundle of sensory axons ascending through the white matter of the spinal cord, carrying sensory information to the brain. It carries pain and temperature sensory information to the thalamus of the brain. It is composed primarily of slow-conducting, sparsely-myelinated Aδ axons and slow-conducting, unmyelinated C axons. These are secondary sensory neurons which have already synapsed with the primary sensory neurons of the peripheral nervous system in the dorsal horn of the spinal grey matter.

Together with the anterior, or ventral spinothalamic tract, the lateral spinothalamic tract is sometimes termed the secondary sensory fasciculus or spinal lemniscus.

Anatomy

The neurons of the lateral spinothalamic tract originate in the dorsal horn and immediately decussate in the anterior commissure to the contralateral side of the spine. The axons pass through the lateral funiculus, then ascend the length of the spine on the medial side of the ventral spinocerebellar fasciculus. On reaching the medulla oblongata they continue in the formatio reticularis near the median fillet and synapse in the ventro-lateral region of the thalamus with tertiary sensory neurons.

Function

The fibres conduct impulses of pain and temperature. Aδ fibres conduct immediate, sharp pain. C fibres conduct dull, burning pain.

See also

• Spinothalamic tract
• Anterior spinothalamic tract

External links

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Last updated on Sunday February 17, 2008 at 10:16:18 PST (GMT -0800)
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