Click on a number in the grid to see the clue or clues for that number.
Complete the crossword, then click on "Check" to check your answer. If you are stuck, you can click on "Hint" to get a free letter.

1		2
								3					4				5
											6				7
8
		9
	10							11
					12														13
	14
																	15
										16
	17
														18
			19
													20

 Check 

Across: 2. Fibre that carries a nerve impulse away from the cell body of a nerve cell. (4) 8. Structure that carries nerve impulses from the retina to the brain. (5,5) 9. A rapid automatic involuntary response to a stimulus. (6,6) 10. Liquid filled tubes in the ear controlling balance. (4-8,5) 14. Cell that carries impulses from the sense organs to the brain. (7,5) 16. Cell that carries impulses from the brain to the muscles. (5,5) 17. Area of the brain responsible for controlling breathing rate, heart rate, etc.. (7) 18. Part of the eye for focussing. (4) 19. Main organ in the Central Nervous System. (5) 20. Thin membrane stretched across the auditiry canal. (3,4)

Down: 1. Reaction shown by a muscle or gland on receiving a stimulus. (8) 2. Carries impulses from the cochlea to the brain. (8,5) 3. Point of the retina where we have the most accurate vision. (5) 4. Light sensitive layer at the back of the eye. (7) 5. Region of the brain responsible for muscle coordination. (10) 6. Opening controlled by the iris. (5) 7. Interaction of different parts of the body allowing them to work efficiently. (12) 11. Transparent layer at the front of the eye. (6) 12. Coiled tube in the inner ear. (7) 13. Region of the brain responsible for memory, intelligence, etc.. (8) 14. Factor that sets off a nerve impulse. (8) 15. Coloured part of the eye. (4)