Question

Pruritus Neural Pathways for Itch -What is the neural pathway for itch?

A) Spinothalamic Tract
B) Somatosensory Cortex
C) Sympathetic Nervous System
D) Somatic Motor Pathway

Answer 1

The sensation of itch is transmitted via the spinothalamic tract, an ascending pathway that crosses over at the level of spinal cord entry and ultimately relays information to the somatosensory cortex.

Step-by-step explanation:

The neural pathway responsible for the sensation of itch is the spinothalamic tract. Itch, along with pain and temperature, is conveyed through this ascending tract from the peripheral receptors in the skin to the central nervous system. The spinothalamic pathway decussates (crosses over) at the level of spinal cord entry and proceeds contralaterally (on the opposite side) to the brain. After reaching the thalamus, the signal is relayed to the somatosensory cortex where the sensation of itch is perceived.

This pathway begins with the activation of receptors by an itchy stimulus, with the first neuronal cell body located in the dorsal root ganglion. Upon entering the spinal cord, the pathway immediately crosses to the other side and ascends to the brain. All three neurons in this pathway play a crucial role, where the third neuron (thalamic neuron) ultimately projects the sensation to the somatosensory cortex for interpretation.