Which tract carries pain and temperature sensations from the body to the brain?

• A. Spinothalamic tract
• B. Corticospinal tract
• C. Dorsal columns
• D. Spinocerebellar tract

Answer: (A)

Pain and temperature from the body travel mainly via the spinothalamic tract, part of the anterolateral system. After the sensory nerve fibers enter the spinal cord, they may ascend a couple of segments in Lissauer’s tract and synapse in the dorsal horn. The second-order neurons then cross to the opposite side at the level of entry and form the spinothalamic tract, which ascends contralaterally to the thalamus. From the thalamus, signals are relayed to the somatosensory cortex. This contrasts with the dorsal columns, which carry fine touch and proprioception; the corticospinal tract, which carries motor commands; and the spinocerebellar tract, which carries unconscious proprioception.