2. Respiratory System
trachea
bronchus (bronchi)
bronchioles

3. Bronchioles & Alveoli
bronchiole
alveoli

4. Nasal Cavity
Nasal cavity possess hairs for trapping large dirt particles
wall of nasal cavity lined with ciliated epithelium and mucus-secreting cells to trap dirt and bacteria

5. near surface are numerous blood vessels
so incoming air are warmed, moistened & filtered before entering lungs

6. Pharynx & Larynx

7. pharynx belongs to both respiratory & digestive system
glottis is the opening of larynx and it is covered by epiglottis during swallowing

8. larynx consists cartilage at the entrance of trachea
within the cartilage are two membranes, vocal cords to produce sound waves

9. Trachea (Windpipe) and Bronchi
trachea lies in front of oesophagus and extended into thoracic cavity
at the lower end of trachea is divided into two bronchi which subdivides into many bronchioles

10. each bronchiole terminates in hollow, lobed air sacs called alveoli
inner lining of the trachea produces mucus and possess cilia

11. mucus are used to trap the dirt & germ while cilia are used to waft the mucus towards the throat, it is then either coughed out or swallowed. Those coughed out are called phlegm
wall of trachea strengthened by C-shaped cartilages to keep trachea open

12. Alveoli Adaptations thin wall ( only one-cell thick)
short diffusion distance for gases
folding shape and numerous alveoli
large surface area for diffusion of gases

13. maintain high concentration gradient of gases
moist surface
to dissolve gases for diffusion
lots of capillaries present

14. Structure of Lung
lungs are protected by the thoracic basket which is made up of vertebrae, ribs and sternum
each lung is surrounded by two pleural membranes

15. the inner membrane is in contact with the lungs and the outer membrane lines against the walls of the thorax and diaphragm
between the two membranes is pleural cavity which contains a pleural fluid secreted by the membranes

16. pleural fluid lubricates the pleura so to reduce friction as the pleural membranes rub against each other during breathing

17. trachea - have ring of cartilage
bronchiole
larynx
Intercostal muscles
trachea have ring of cartilage
pleural fluid
left lung
left bronchus
alveoli
heart
pleural membranes
diaphragm
rib

18. Thoracic Basket (rib cage)
sternum
ribs
vertebrae
pleural cavity
- absorb shock
2 pleural membranes

19. Gaseous Exchange in Alveoli
atmosphere
CO2 O2
Lungs(alveoli)
CO2 (by plasma and in form of HCO3- )
O2 + haemoglobin
oxyhaemoglobin
(by red blood cell)
tissue

20. Gaseous Exchange in Alveoli
Deoxygenated blood
Lung
Pulmonary artery
Oxygenated blood
Heart
Tissue
Pulmonary vein
Oxygenated blood

21. air moves out during expiration air moves in during inspiration
CO2
deoxygenated blood from pulmonary artery
oxygenated blood to pulmonary vein
cell in capillary wall
plasma
cell in alveolar wall
mucus
red blood cell

22. Mechanism of Breathing
brought about by the action of diaphragm & intercostal muscles
divided into two processes : inhalation (inspiration) & exhalation (expiration)

23. Inspiration (Inhalation)
Diaphragm muscle
- contract
Diaphragm
- flattened
Intercostal muscle contract
ribs & sternum
- move upward & outward

24. Inspiration (Inhalation)
thoracic cavity expands (volume increases)
air pressure in lung is lower than atmospheric pressure so air rushes in
lungs inflated (expand)

25. Expiration (Exhalation)
diaphragm muscles relax
diaphragm becomes dome-shaped
intercostal muscles relax
ribs and sternum move downwards & inwards

26. thoracic cavity volume decreases
air pressure inside lungs increases
air forces out
lungs deflated

27. Walking & Running during exercise at rest lung volume ( cm )
time (seconds) 5 10 15
1000
2000
3000 3 20
during exercise
time (seconds) 20 5 10 15
1000
2000
3000
lung volume ( cm ) 3
at rest

28. Calculations of the Rate and Depth of Breathing
From the graphs the volume of air he breathed in per minute at rest and during exercise can be measured :

30. If the percentage by volume of oxygen in atmospheric air is 21% and that in exhaled air is 16%. Then the volume of oxygen retained in the body per minute can then be calculated :
At rest : 18 x 500 x (21-16)% = 450cm3
During exercise : 27 x 2000 x (21-16)%
=2700cm3

31. CO2 remains Constant during Exercise
muscles release CO2
ventilation rate increases + 
CO2 concentration in blood remains CONSTANT

32. The graph of Lung capacities

33. Tidal Volume
amount of air entering & leaving the lungs during normal breathing
during exercise → can increase volume

34. Vital Capacity maximum air exhaled after taking the deepest inhalation
during exercise → cannot increase the capacity
increase only after prolong training

35. Residual Volume
volume of air remaining in the lungs which cannot be expelled even after forced exhalation

36. Smoking & Health Composition of a cigarette : carbon monoxide
+ nicotine
+ tar
= cigarette
Effects on health :
(I) Tar :
(i) carcinogenic ( producing cancer )
(II) Nicotine :
(i) cause heart diseases

37. Smokers’ lung

38. (ii) dependence
(iii) retards growth of foetus
(III) Carbon Monoxide :
(i) combines irreversibly with haemoglobin and
prevents it from carrying oxygen
+ CO
haemoglobin
carboxyhaemoglobin
(ii) decrease in physical fitness
(iii) cause air pollution

39. Smoking and Health Hazards
1.Lung Cancer
Smoking increase the risk of lung cancer
2.Heart disease
Nicotine increases the workload of heart
increase the rate of heart attack

40. Smoking and Health Hazards
3.Chronic bronchitis
Smoking causes inflammation of trachea and
bronchitis
The severe chronic bronchitis can cause death
4.Emphysema
Causes of "smoker's cough"
Smoker cough causes damage of alveolar wall in lungs

41. Passive Smoking Warning DO NOT SMOKE !!!!!
process of breathing in smoke from cigarette smokers
causes nose, throat & eye irritations
Warning
DO NOT SMOKE !!!!!