| A | B |
|---|
| brain stem | controls involuntary functions |
| central nervous system | made of the brain and spinal cord |
| cerebellum | coordinates voluntary muscle movement and regulates balance and posture |
| cerebrum | controls memory, language, and thought |
| nervous system | gathers, processes, and responds to information |
| neuron | basic functioning unit of the nervous system |
| peripheral nervous system | sensory and motor neurons that transmit information between the central nervous system and the rest of the body |
| physical | relating to material things |
| reflex | automatic movement in response to a stimulus |
| spinal cord | tubelike structure of neurons |
| stimulus | change in an organism’s environment that causes a response |
| synapse | gap between two neurons |
| eardrum | thin membrane between the outer ear and the inner ear |
| receptor | special structure within the sensory system that detects stimuli |
| retina | area at the back of the eye that contains photoreceptors |
| rod | photoreceptor in the eye that distinguishes shapes of objects |
| sensory system | part of the nervous system that detects or senses the environment |
| wave | disturbance that transfers energy without transferring matter |
| endocrine system | consists of organs and tissues that release chemical messages into the bloodstream |
| hormone | chemical produced by an endocrine gland in one part of an organism and carried in the bloodstream to another part |
| negative feedback | control system where the effect of a hormone inhibits further release of the hormone |
| positive feedback | control system in which the effect of a hormone causes more of the hormone to be released |
