Nervous system

6. The branched endings of a neurone that receive impulses from other neurones (9)
9. The neurone that carries impulses from receptors to the CNS (7)
10. The chemical that carries the nerve signal across a synapse (15)
13. A change in the environment that is detected by receptors (8)
14. The neurone that connects sensory and motor neurones in the CNS (5)
15. A muscle or gland that carries out a response to a stimulus (8)
17. The regulation of internal conditions to maintain a stable environment (11)
19. A fatty layer that insulates axons and speeds up impulses (6)
20. The type of neurone that carries impulses to effectors (5)

1. The pathway taken by a nerve impulse in an automatic response (6,3)
2. A nerve cell that carries electrical impulses (7)
3. What the body does after detecting a stimulus (8)
4. The long fibre of a neurone that carries electrical impulses away from the cell body (4)
5. A structure that detects stimuli such as light or temperature (8)
7. The type of signal transmitted along neurones (10)
8. The small gap between two neurones where neurotransmitters are released (7)
11. The main control centre of the nervous system (5)
12. A fast, automatic response that protects the body from harm (6)
16. The abbreviation for the central nervous system (3)
18. Structure in the backbone that is part of the central nervous system (6,4)