Human Nervous System

A stimulus is any change in the environment that causes a response in an organism. For example, bright light causes you to squint.

Motor neurons are nerve cells that conduct impulses from the brain or spinal cord to muscles, enabling movement.

The central nervous system (CNS) is the main control center of the body, consisting of the brain and spinal cord, coordinating body activities.

The brain is the main control center of the body, responsible for processing information and controlling voluntary actions.

Motor output is the response generated by the brain, which sends signals to muscles to produce movement.

Sensory neurons are nerve cells that receive information from sensory receptors and send impulses to the brain.

The spinal cord connects the brain to the rest of the body and transmits signals between them.

A reflex action is an automatic response to a stimulus that does not involve conscious thought, such as pulling your hand away from a hot surface.

The autonomic nervous system controls involuntary bodily functions, such as heart rate and digestion.

Voluntary actions are controlled consciously, while involuntary actions occur automatically without conscious control.