I believe this would be the correct order:
1) A receptor detects a signal.
2) A sensory neuron sends a signal to the spinal cord.
3) A relay neuron sends a signal to a motor neuron.
4) A muscle receives a signal to contract.
5) A bone moves.
A signal will be picked up by a sensory neuron and sent to the spinal cord (Central Nervous System). The signal will then be sent to a motor neuron in the Peripheral Nervous System to find a muscle. That muscle is signaled to contract which then will cause a bone to move.
