What is the role of a motor unit?

What is the role of a motor unit?

• A. To contract a single muscle in response to a nerve impulse
• B. To relax a group of muscle fibres in response to a nerve impulse
• C. To contract a group of muscle fibres in response to a nerve impulse
• D. To relax a single muscle fibre in response to a nerve impulse

Answer: (C)

The role of a motor unit is to contract a group of muscle fibers in response to a nerve impulse. A motor unit consists of a single motor neuron and all the muscle fibers it innervates. When the motor neuron is stimulated, it sends an electrical signal that causes all the muscle fibers within that unit to contract simultaneously. This contraction is crucial for generating muscle force and facilitating movement. The coordination of multiple motor units allows for varying levels of muscle contraction, which can range from fine motor control to powerful, sustained efforts depending on the task at hand. This mechanism is fundamental for the functioning of skeletal muscles during physical activity.

The role of a motor unit is to contract a group of muscle fibers in response to a nerve impulse. A motor unit consists of a single motor neuron and all the muscle fibers it innervates. When the motor neuron is stimulated, it sends an electrical signal that causes all the muscle fibers within that unit to contract simultaneously. This contraction is crucial for generating muscle force and facilitating movement. The coordination of multiple motor units allows for varying levels of muscle contraction, which can range from fine motor control to powerful, sustained efforts depending on the task at hand. This mechanism is fundamental for the functioning of skeletal muscles during physical activity.