The nervous system communicates with muscles primarily through neurons, specifically via motor pathways and neuromuscular junctions.
Here's a more detailed explanation:
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Motor Pathways (Neurons and Spinal Cord): Neurons act as messengers between the brain and muscles. Signals originating in the brain travel down the spinal cord through motor pathways. These pathways consist of chains of neurons that relay the signal from the brain to the specific muscle or muscles that need to be activated. This allows for voluntary movements controlled by conscious thought. The reference mentions that outgoing signals travel along motor pathways to activate muscles, directly confirming this method of communication.
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Neuromuscular Junctions (Chemical Synapses): Once the signal traveling along the motor neuron reaches the muscle, it arrives at the neuromuscular junction. This is a specialized synapse where the motor neuron's axon terminal communicates directly with the muscle fiber. At the neuromuscular junction, the motor neuron releases a chemical neurotransmitter (acetylcholine is a common one) which then diffuses across the synaptic cleft and binds to receptors on the muscle fiber membrane. This binding triggers a series of events that ultimately lead to muscle contraction.
In summary, the nervous system uses electrical signals transmitted through neurons in motor pathways to carry information from the brain to the muscle, and then relies on chemical signals (neurotransmitters) at neuromuscular junctions to initiate muscle contraction.
