Motor unit

A motor unit is a basic functional component of your muscles, consisting of a single nerve cell (motor neuron) and all the muscle fibers it controls. When the brain or spinal cord sends a signal to move, the nerve activates its motor unit, causing those muscle fibers to contract simultaneously. This process enables precise control of muscle movements—small motor units allow subtle movements, while larger units generate more force. Essentially, motor units work together to coordinate muscle action efficiently, allowing everything from delicate tasks like writing to powerful movements like lifting heavy objects.