I use the _ nervous system when I tell my arm to reach out and grab a pencil.
The correct answer and explanation is:
The correct answer is the somatic nervous system.
The somatic nervous system is part of the peripheral nervous system that controls voluntary movements of the body. It is responsible for actions that are consciously controlled, like moving your arm to grab a pencil. When you decide to perform a task such as reaching out for an object, your brain sends signals through the somatic nervous system to the muscles involved, prompting them to contract and execute the action.
The somatic nervous system consists of sensory and motor neurons. The sensory neurons carry information from sensory receptors (like those in your skin, muscles, and joints) to the central nervous system (CNS), while motor neurons transmit commands from the CNS to the muscles. These motor neurons carry the signal to specific muscles, telling them when and how to contract to create movement.
When you reach for the pencil, the brain’s motor cortex sends a signal down the spinal cord and out to the muscles of the arm via the motor neurons. The muscles then contract, moving the arm in the intended direction. This process involves the coordination of various structures, including the brain, spinal cord, and the muscles themselves. The action is voluntary, meaning you consciously decide to perform it, which differentiates the somatic nervous system from the autonomic nervous system, which controls involuntary functions like heart rate and digestion.
In summary, the somatic nervous system enables voluntary movements and is essential for activities like reaching out to grab a pencil, controlling muscle contractions, and carrying out everyday physical tasks that require conscious thought and coordination.