Which pathway carries pain signals from the body to the brain?

• A. Ascending pain pathway
• B. Descending pain pathway
• C. Peripheral nerve pathway
• D. Hormonal pain route

Answer: (A)

Pain signals start when nociceptors detect harmful stimuli, sending information via small-diameter afferent fibers to the dorsal horn of the spinal cord. From there, second-order neurons cross and ascend through the spinothalamic tract to the thalamus and onward to the somatosensory cortex, where we consciously perceive and localize pain. This ascending transmission is the pathway that carries nociceptive information from the body up to the brain. The descending pathway, by contrast, comes from the brain and modulates that input at the spinal level. A generic peripheral nerve route isn’t specific to pain signaling to the brain, and a hormonal route isn’t the mechanism for direct nociceptive transmission.