How does the brain communicate with muscles during voluntary actions, and what is the second way in which the nervous system communicates with muscles?

During voluntary actions, the brain communicates with muscles through the nervous system via two main pathways. The first involves the upper motor neurons in the primary motor cortex sending signals, known as action potentials, down the spinal cord. These signals travel through the motor neurons of the spinal cord and then reach the muscles, leading to the initiation of voluntary movements.