What part of the neuron transmits messages to muscles?

The part of the neuron that transmits messages to muscles is the axon. The axon is a long, thin projection that extends from the neuron's cell body. It is responsible for transmitting electrical signals from the neuron to other cells, including muscle cells. When an electrical signal reaches the end of the axon, it causes the release of neurotransmitters, which are chemical messengers that bind to receptors on the muscle cells and cause them to contract.