Which is the primary function of the motor nerves?

The primary function of motor nerves is to control voluntary muscle movement. These nerves are responsible for transmitting signals from the brain and spinal cord to skeletal muscles, enabling actions such as walking, running, and grasping objects. When the brain sends a signal through the motor nerves, it causes the corresponding muscles to contract, allowing for the execution of purposeful movements.

In contrast, connections to sensory organs and the relaying of sensory information primarily involve sensory nerves, which convey information from the body's sensory receptors to the brain for processing. Involuntary bodily functions are typically managed by autonomic nerves, which regulate processes such as heart rate and digestion without conscious effort. Therefore, the distinct role of motor nerves in orchestrating voluntary movement underscores why the correct answer is focused on their control of muscle activity.