17+ Motor Unit Diagram. Web a motor unit comprises a motor neuron and the muscle fibers it innervates, illustrated here by motor neuron a1. Neuromuscular junction and motor unit.
Sliding filament model of muscle contraction. The motor neuron may innervate multiple muscle fibers, which are single cells, but only one motor neuron innervates a single muscle fiber. (b) each motor neuron synapses with multiple muscle fibers.