C14: coordination & response

• stimulus - any change in the environment that can be detected by sensory neurons
• receptor - structure that detects a stimulus and generates an electrical impulse to be sent to the central nervous system
• effector - structure that responds to a signal from the nervous system, resulting in a specific action or behaviour
• reflex action - means of automatically and rapidly integrating and coordinating stimuli with the responses of effectors
• sense organ - group of receptor cells that respond to specific stimuli
• hormone - a chemical substance produced by a gland and carried by the blood