Which neurons carry information from the brain and spinal cord to the muscles?

Which neurons carry information from the brain and spinal cord to the muscles?

• A. Sensory neurons
• B. Interneurons
• C. Glial cells
• D. Motor neurons

Answer: (D)

The key idea is that signals traveling from the brain and spinal cord to the muscles use motor neurons. These neurons are the efferent pathway that carries commands from the central nervous system to skeletal muscles, causing them to contract. Motor neurons originate in the brainstem or spinal cord and extend to muscle fibers, where they release neurotransmitters (such as acetylcholine) to trigger a muscle response at the neuromuscular junction. In contrast, sensory neurons carry information from the body back to the CNS (afferent signals), interneurons connect neurons within the CNS to process information, and glial cells provide support and insulation for neurons but do not primarily transmit motor commands.

The key idea is that signals traveling from the brain and spinal cord to the muscles use motor neurons. These neurons are the efferent pathway that carries commands from the central nervous system to skeletal muscles, causing them to contract. Motor neurons originate in the brainstem or spinal cord and extend to muscle fibers, where they release neurotransmitters (such as acetylcholine) to trigger a muscle response at the neuromuscular junction.

In contrast, sensory neurons carry information from the body back to the CNS (afferent signals), interneurons connect neurons within the CNS to process information, and glial cells provide support and insulation for neurons but do not primarily transmit motor commands.