A group of muscle cells connected to a single motor nerve is known as what?

A group of muscle cells connected to a single motor nerve is known as what?

• A. Muscle fiber
• B. Motor unit
• C. Sarcomere
• D. Tendon

Answer: (B)

A motor unit is the functional unit of muscle control: one motor neuron and all the muscle fibers it stimulates. When that neuron fires, every fiber in its motor unit contracts together, producing a coordinated twitch. The size of a motor unit can vary—some muscles use small units for fine, precise movements, while others use large units with many fibers to generate more force. By contrast, a single muscle fiber is just one cell, a sarcomere is the contractile unit inside that fiber, and a tendon is connective tissue that attaches muscle to bone.

A motor unit is the functional unit of muscle control: one motor neuron and all the muscle fibers it stimulates. When that neuron fires, every fiber in its motor unit contracts together, producing a coordinated twitch. The size of a motor unit can vary—some muscles use small units for fine, precise movements, while others use large units with many fibers to generate more force. By contrast, a single muscle fiber is just one cell, a sarcomere is the contractile unit inside that fiber, and a tendon is connective tissue that attaches muscle to bone.