Final answer:
Motor neurons are the nerves responsible for sending impulses from the brain and spinal cord to skeletal muscles, causing them to contract. They are composed of axons that bundle together to form nerves, transmitting action potentials that instruct the muscles to activate.
Step-by-step explanation:
The nerves that send impulses from the brain and spinal cord to skeletal muscles are known as motor neurons. These neurons transmit action potentials, which are necessary for muscular contractions.
Motor neurons that serve the skeletal muscles of the face, head, and neck, have their cell bodies located in the brainstem, while the rest originate in the spinal cord. The long processes of these neurons, called axons, are bundled together to form nerves, acting like wires in a cable to send electrical signals over long distances.
The spinal cord operates as a crucial information highway in this process, with sensory neurons carrying impulses to the brain and motor neurons transmitting instructions from the brain to muscles and glands.
Motor neurons are considered efferent neurons, which means they carry signals away from the central nervous system to activate muscles and glands.
Each spinal nerve combines sensory and motor fibers, facilitating a two-way communication system between the spinal cord and the body. The motor fibers specifically emerge from the anterior horn of the spinal cord, connecting to skeletal muscles, thus facilitating movement.