1. Respiratory system

2. What is Respiration?
 The release of energy from food

3. Burning of Food oxygen food (sugar) Burning energy carbon dioxide
 Energy released from food
oxygen
food (sugar)
Burning
energy
carbon dioxide
water

4. food (sugar) + oxygen
burning
carbon dioxide + water + energy (heat + light)
 does not occur in living cells because the reaction is too fast and cells would die as they become so hot

5. Respiration  reactions are catalyzed by enzymes
 main food substance which is oxidized in cells is glucose
enzymes
C6H12O6
+ 6O2
6CO2
+ 6H2O
+ energy
glucose + oxygen ➨ carbon dioxide + water energy

6. Respiration
respiration that takes place in plants and animals uses oxygen
is called aerobic respiration
some bacteria do not require oxygen and this is called anaerobic respiration

7. Comparison of Burning and Aerobic Respiration
Similarities
- both involve oxidative processes
- both require the use of oxygen and food and they produce the same products of carbon dioxide and water
- both reactions release energy

8. Differences  takes place in air or oxygen  takes place in cells
Burning
Respiration
 takes place in air or oxygen
 takes place in cells
 a single-step process
 a series of chemical reactions
 no enzymes involved
 controlled by enzymes

9. Differences Burning Respiration
 energy release is vigorous and not under control
 energy release is slower and under control
 energy is released in form of heat and light (a flame can result)
 energy is released in form of heat and an energy-rich compound

11. Respiratory Structures and Organs
Larynx
(voicebox)
Trachea
(windpipe)
Ribs
Bronchus
Bronchiole
Alveoli
Pleural
membrane
Diaphragm

13. Respiratory Structures and Organs
trachea
bronchus (bronchi)
bronchioles

14. Respiratory Structures and Organs
 Lungs
– pair of cone-shaped
– made of elastic tissue
– divided into lobes

15. Respiratory Structures and Organs
 Trachea (windpipe)
tubular passage way for air
carries air to the lungs
C-shaped cartilage rings
divides at end

16. Respiratory Structures and Organs
 Bronchi
pair of tubes that branch from trachea and enter lungs

17. Respiratory Structures and Organs
 Bronchioles
– tiny tubes

18. Respiratory Structures and Organs

19. Respiratory Structures and Organs
 Alveoli
– cup shaped structures at the end of the
bronchioles, resemble bunches of grapes
– are in direct contact with capillaries
– gaseous exchange brings O2
into the blood from the air and
releases CO2 from the blood
into the air

20. Gaseous Exchange air moves in and out
oxygenated blood to pulmonary vein
deoxygenated blood from pulmonary artery
cell in capillary wall
CO2
plasma O2
cell in alveoli wall
mucus
red blood cell

21. Gaseous Exchange

22. Gaseous Exchange
Earth’s atmosphere is about 78% nitrogen and about 21% oxygen
What happens to the air when we inhale?
300 million alveoli in a healthy lung
Haemoglobin can hold four O2 molecules
GAS
INHALED
EXHALED O2
20.71%
14.6%
CO2
.004%
4.0%
H2O
1.25%
5.9%

23. Mechanics of Breathing
 Inhaling (active process) – Air moves in
 Gases move from an area of
high pressure to low pressure
 During inhalation – diaphragm
pulls down and lungs expand
 When lungs expand, it increases the
volume, which decreases the pressure
inside lungs
 Lung pressure is lower than outside pressure, so air moves in

24. Mechanics of Breathing
 Exhaling (passive process) – breathing out
 Diaphragm and muscles relax
 Volume in lungs and chest cavity
decreases, so now pressure inside
increases
 Air moves out because pressure
inside is higher than outside atmosphere

26. Respiratory System Disorders
 Asthma – muscles of bronchioles constrict, drastically reducing ventilation
 Emphysema – destruction of alveoli
 Tuberculosis – highly contagious bacterial infection
 Lung cancer – 90% of
lung cancer victims have
a history of smoking

27. The real reason dinosaurs became extinct

28. Smoking & Health  Composition of a cigarette :
cigarette = carbon monoxide + nicotine + tar
 Effects on health :
 Tar :
– carcinogenic ( producing cancer )

29. Smokers’ lung

30. Smoking & Health  Nicotine : – cause heart diseases– dependence
– retards growth of foetus
 Carbon Monoxide :
– combines irreversibly with haemoglobin and
prevents it from carrying oxygen
– decrease in physical fitness
– cause air pollution

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