A single motor neuron typically synapses with about 150 skeletal muscle fibers on average. This means one motor neuron connects to and controls roughly 150 muscle cells, forming what is called a motor unit
. This number can vary depending on the muscle and the precision of control required. For example, muscles requiring fine motor control (like those controlling eye movements) have motor neurons that synapse with fewer muscle fibers, while large muscles involved in gross movements have motor neurons connecting to many more muscle fibers. The synapse between a motor neuron and a muscle fiber is called the neuromuscular junction, a specialized chemical synapse that allows the neuron to transmit signals to the muscle to trigger contraction
. In summary:
- One motor neuron synapses with approximately 150 muscle cells on average
- This synapse is called the neuromuscular junction
No exact single number applies universally, but 150 muscle fibers per motor neuron is a widely accepted average figure.
