Which type of neurons innervate skeletal muscles?

Lower motor neurons are the correct choice because they are the specific type of neurons that directly innervate skeletal muscle fibers at the neuromuscular junction. These neurons reside in the anterior horn of the spinal cord or in specific cranial nerve nuclei and their axons extend out to skeletal muscles, facilitating voluntary muscle contraction.

When a signal is sent from the brain to initiate movement, upper motor neurons send impulses down to lower motor neurons. However, it is the lower motor neurons that actually make contact with muscle fibers to induce contraction. This direct connection is crucial for producing the movements required for various motor activities.

The other types of neurons listed do not have this function. Interneurons primarily facilitate communication between sensory and motor neurons within the central nervous system and do not directly innervate muscles. Upper motor neurons, although essential for conveying signals to lower motor neurons, do not directly connect to the muscle itself. Sensory neurons are responsible for transmitting sensory information to the central nervous system and are not involved in muscle innervation. Therefore, lower motor neurons are integral to the functioning of skeletal muscle contraction.