Motor Units

A motor unit consists of a motor neuron (a nerve cell) and the muscle fibers it controls. When the brain sends a signal to move, the motor neuron activates, causing all its connected muscle fibers to contract simultaneously. This setup allows precise control of muscle strength and movement. The size of a motor unit varies; small units enable fine movements, like in your fingers, while larger ones are involved in powerful actions, like in your thigh. Understanding motor units helps explain how our nervous system coordinates muscle activity to perform different tasks effectively.