Action potentials travel the length of the axons of motor neurons to the axon terminals. These motor neurons __________?
1) arise in the epimysium of a skeletal muscle and extend to individual skeletal muscle fibers
2) extend from the spinal cord to the sarcolemma of a skeletal muscle fiber
3) extend from the brain or spinal cord to the sarcolemma of a skeletal muscle fiber
4) extend from the brain to the sarcolemma of a skeletal muscle fiber
