| A | B |
|---|
| nervous system | responds to stimuli to help maintain the body's homeostasis |
| stumuli | internal or external change that brings about a response |
| homeostasis | regulation of steady, life-maintaining conditions inside an organism despite changes in its environment |
| neurons | basic units of nervous system |
| dendrites | receive messages from other neurons and send them to the cell body |
| axons | carry messages away from the cell body |
| impulse | message carried by neurons |
| sensory neurons | receive information and send impulses to brain or spinal cord |
| interneurons | transport impulses |
| motor neurons | conduct impulses from brain or spinal cord to muscles and glands |
| synapse | small space between neurons where impulses cross |
| brain | coordinates all the body's activities |
| cerebrum | largest part of brain where memories are stored, movements are controlled, and impulses from senses are interpreted |
| cerebellum | controls voluntary muscle movement and maintains muscle tone and balance |
| brain stem | connects brain to spinal cord and controls involuntary muscle movement |
| spinal cord | carries impulses between brain and body and controls reflexes |
| reflex | involuntary, automatic response to a stimulus |
