Which statement correctly describes the roles of afferent and efferent cells?

• A. Afferent cells carry sensory information; efferent cells carry motor information
• B. Afferent cells carry motor information; efferent cells carry sensory information
• C. Afferent cells carry sensory information; efferent cells carry sensory information
• D. Afferent cells carry motor information; efferent cells carry motor information

Answer: (A)

In the nervous system, directions are always about where the information is going relative to the central nervous system. Afferent pathways bring sensory information from the body and the external environment toward the brain and spinal cord. Efferent pathways carry commands from the brain and spinal cord out to effectors like muscles and glands, producing a response. A helpful image is touching something hot: the sensation travels along afferent (sensory) fibers to the CNS, the brain processes it, and then efferent (motor) fibers send the withdrawal command to the muscles. So the statement that afferent cells carry sensory information and efferent cells carry motor information is the correct description. The other options mix up these directions or pair sensory with motor incorrectly.