1. GASEOUS EXCHANGE

2. Oxygen is needed for _______________

3. Oxygen is needed for cellular respiration.

4. What is the difference between breathing and gaseous exchange?
Discuss with a peer. 1 and half minutes

5. After respiration the oxygen gas is changed into ______________, If CO2 accumulate it joins with water forming carbonic acid → change pH → affect enzymes
Carbon dioxide

6. Requirements for an efficient gas exchange system
See table pg 205
Large, moist and thin surface
A transport system
Ventilating mechanism
protection

7. How requirements are satisfied in different organisms (see pg 206-207)

12. Volume to surface area ratio pg 208

13. Gaseous exchange system in humans
AIR PASSAGE: Nasal passage (warmed, moistened and cleaned of dust and germs) → → pharynx → trachea (has c-shaped cartilage to keep it open)

14. Trachea → 2 bronchi → bronchioles → alveolus

15. Adaptations of air passages see table pg 211

16. The lungs (pg 213)

17. Internal structure of lung

18. Adaptations (pg 214)

19. ACTIVITy pg 220 no 1-3

20. ACTIVITy pg 220 no 1-3
1 a) F b) B c) A d) J e) K f) C 2 rib cage Fluid of pleural membrane 3. C- Rib D- intercostal muscle G- Trachea H- Pulmonary artery I- Pulmonary vein

21. Breathing PRAC pg

22. Breathing see table on pg 217
Inhalation and exhalation difference.

23. Act pg 218

24. TEST FOR co2
Clear lime water turned milky in the presence of CO2

25. Modification of breathing rate
Can be modified voluntarily within limits . Average of 15 breaths per minute. See flow diagram pg 224- How breathing rate is controlled involuntarily. *Homeostasis

26. Gaseous exchange and transport
AT LUNGS O2 moves from lungs to capillaries and CO2 moves from the capillaries to the lung by DIFFUSION. OXYGEN TRANSPORT Oxygen + haemoglobin (RBC) = oxyhaemoglobin Some also dissolved in plasma. → left side of heart → aorta → all cells of the body.

27. ….Gaseous exchange and transport
AT THE TISSUES: O2 moves from the capillaries to the tissues and CO2 from the tissues to the capillaries by DIFFUSION. TRANSPORT OF CO2 Mostly: CO2 + H2O (plasma) = carbonic acid → bicarbonate ions Some dissolves in blood plasma Some CO2 + haemoglobin = carbhaemoglobin → Right of heart → lungs

28. Activity pg

29. Availability of O2 at high altitudes pg 228
Air at high altitudes is less dense and thus has less O2 People living high altitudes breath more deeply and quickly, they also have more red blood corpuscles.

30. ACTivity pg

31. Diseases and allergies of the gas exchange system
Allergen- something which causes an allergic reaction Disease- normal functioning is disturbed. SEE TABLE PG 231

32. asthma

33. Hay fever

34. Lung cancer

35. tb

36. bronchitis

37. Emphysema

38. TB (video + PG )
CAUSES SPREAD SYMPTOMS TEST VACCINE TREATMENT

39. SMOKING

40. ARTIFICIAL RESPIRATION