What are the functions of the spinothalamic tracts?

• A. They control fine motor coordination
• B. They regulate proprioception
• C. They carry sensations of pain, temperature, and crude and light touch from the body to the brain
• D. They modulate muscle tone

Answer: (C)

The spinothalamic tracts relay sensory information about pain, temperature, and crude/light touch from the body to the brain. They’re part of the anterolateral system, and after entering the spinal cord, the signals cross to the opposite side near their entry point and then ascend to the thalamus before reaching the somatosensory cortex. This pathway explains why pain and temperature sensations often appear on the side opposite a spinal issue below the lesion. Fine motor coordination is handled by motor pathways, proprioception comes mainly from the dorsal columns (and some spinocerebellar tracts), and modulation of muscle tone is governed by descending motor systems in the brainstem and spinal cord—not the spinothalamic tracts.