2. LEFT CLICK OR PRESS SPACE BAR TO ADVANCE, PRESS P BUTTON TO GO BACK, PRESS ESC BUTTON TO END LEFT CLICK OR PRESS SPACE BAR TO ADVANCE, PRESS P BUTTON TO GO BACK, PRESS ESC BUTTON TO END COMPUTER PRESENTATIONS FOR KS3 SCIENCE - BIOLOGY ©2003, STEVE PARKER COMPUTER PRESENTATIONS FOR KS3 SCIENCE - BIOLOGY ©2003, STEVE PARKER

3. 1 1 KS3 SCIENCE - BIOLOGY KS3 SCIENCE - BIOLOGY Breathing

4. THE LUNGS 2 2

5. 3 3 Throat Bronchus Bronchioles Alveoli Ribs Heart Trachea (wind pipe) The main features of the Lungs The main features of the Lungs

6. THE LUNGS 4 4 The air travels down through the bronchioles to the alveoli, which are tiny air sacs with thin walls and a good Blood supply The air travels down through the bronchioles to the alveoli, which are tiny air sacs with thin walls and a good Blood supply

7. THE LUNGS 5 5 The alveoli allow gases to be exchanged between the lungs and the blood The alveoli allow gases to be exchanged between the lungs and the blood Blood Capillary Blood Capillary Alveoli Blood Flow Blood Flow

8. THE LUNGS 6 6 Oxygen-rich air is breathed into the lungs, and then diffuses into the blood Oxygen-rich air is breathed into the lungs, and then diffuses into the blood Blood Capillary Blood Capillary Alveoli Blood Flow Blood Flow

9. THE LUNGS 7 7 The body uses up oxygen and produces carbon dioxide, and this diffuses out into the lungs The body uses up oxygen and produces carbon dioxide, and this diffuses out into the lungs Blood Capillary Blood Capillary Alveoli Blood Flow Blood Flow

10. MECHANICS OF BREATHING 8 8

11. 9 9 The natural state of the body is for the chest to be relaxed and the Diaphragm curved in The natural state of the body is for the chest to be relaxed and the Diaphragm curved in Diaphragm

12. MECHANICS OF BREATHING 10 When we breathe in, the chest rises and expands and the diaphragm is pulled down When we breathe in, the chest rises and expands and the diaphragm is pulled down

13. MECHANICS OF BREATHING 11 To breathe out, the chest relaxes, falling down, and the diaphragm relaxes, coming back up again To breathe out, the chest relaxes, falling down, and the diaphragm relaxes, coming back up again

14. MECHANICS OF BREATHING 12 As the chest gets bigger, air is drawn in, and when it gets smaller again air is pushed back out As the chest gets bigger, air is drawn in, and when it gets smaller again air is pushed back out

15. MECHANICS OF BREATHING 13 As the chest gets bigger, air is drawn in, and when it gets smaller again air is pushed back out As the chest gets bigger, air is drawn in, and when it gets smaller again air is pushed back out

16. MECHANICS OF BREATHING 14 As the chest expands the volume inside increases, so air rushes in to fill the space As the chest expands the volume inside increases, so air rushes in to fill the space

17. MECHANICS OF BREATHING 15 As the chest expands the volume inside increases, so air rushes in to fill the space As the chest expands the volume inside increases, so air rushes in to fill the space When the chest gets smaller, the volume is reduced, forcing air out When the chest gets smaller, the volume is reduced, forcing air out

18. RESPIRATION 16

19. RESPIRATION 17 Respiration is not breathing, it is a chemical reaction that produces energy using sugars and oxygen Respiration is not breathing, it is a chemical reaction that produces energy using sugars and oxygen

20. RESPIRATION 18 Respiration takes place in the Cytoplasm of Cells which are supplied with sugars and oxygen through the blood Respiration takes place in the Cytoplasm of Cells which are supplied with sugars and oxygen through the blood

21. RESPIRATION 19 Besides energy, the products from respiration are carbon dioxide and water, which are taken away by the blood Besides energy, the products from respiration are carbon dioxide and water, which are taken away by the blood