Afferent fibers responsible for pain transmission to the spinal cord are called what?

• A. Efferents
• B. Interneurons
• C. Receptors
• D. Afferents

Answer: (D)

Pain signals travel from the body toward the spinal cord via sensory, or afferent, fibers. Afferent means carrying information toward the central nervous system, which is why these fibers are described as responsible for transmitting pain to the spinal cord. In contrast, efferent fibers carry commands away from the CNS (motor), interneurons are neurons within the spinal cord that connect other neurons and help relay signals, and receptors are the sensory endings that detect stimuli in the periphery. In pain pathways, the peripheral nociceptors detect noxious stimuli and send signals along small-diameter afferent fibers (A-delta and C fibers) to the spinal cord, where transmission and modulation occur.