The Nervous System

3. a nerve forming a pathway along which neurons can pass from the central nervous system to a muscle or gland
5. a thing or event that evokes a specific functional reaction in an organ or tissue
10. the nerves that connect the central nervous system to the rest of the body
12. an organ or cell that acts in response to stimuli
14. a sensory cell or organ responsive to chemical stimuli
15. a regulatory substance produced in an organism to stimulate specific cells or tissues into action

1. the system where glands secrete hormones or other products into the blood
2. the stability of the internal environment in which a cell lives
4. receptor -> control centre -> effector -> response
6. composed of the brain and the spinal cord, a group of nerve tissues that controls the activities of the body
7. when the response travels in the same direction as the stimulus
8. when the response is in an opposite direction to the stimulus
9. the nerve cells within the nervous system responsible for converting external stimulus into internal electrical impulses
11. a pulse of electrical energy
13. a receiver of external stimulus, such as light or heat, which can send signals to sensory nerves