Science - Respiration - Form - 3 - PPT S

KSSM Form 3 Science Chapter 2: Respiration

1. RESPIRATION

2. •Respiration = chemical process whereby
energy is released from glucose or other
simple substances
•Oxygen taken into body when we breathe
•Glucose from food we eat
•Exchange of gases known as breathing
Human breathing mechanism
Glucose + oxygen energy + carbon dioxide + water

3. Structure of human respiratory
system

4. Structure of lung

5. •Lungs are made up of :
–bronchioles
–Alveoli (singular : alveolus)
–Blood capilaries
•Lungs are protected by rib cage
•Thoracic cavity = houses of the lung

6. Flow of air from the atmosphere to
the lungs
Alveolus
Nostril
Bronchiole
Bronchus
Trachea
Nasal cavity

7. •Gaseous exchange takes place in the
lungs by diffusion

8. •An alveolus has adaptations to allow it to
exchange gases effectively. It has:
–Large surface area
–Thin and elastic walls
–Surround by a network of blood capillaries
–Moist surface

9. •Process of taking air into lung = inhalation
•Air enter lung = inhaled air
•Process of expelling air from lung =
exhalation
•Air expelled from lung = exhaled air
The breathing mechanism

10. Inhalation

11. Exhalation

12. Inhalation Exhalation
External intercostal
muscles contract
External intercostal
muscles relax
Rib cage moves upwards
and outwards
Rib cage moves
downwards and inwards
The diaphragm contracts
and flattens
The diaphragm relaxes
and curves upwards
The volume of the
thoracic cavity increase
The volume of the
thoracic cavity decrease
The air pressure in the
thoracic cavity decreases
The air pressure in the
thoracic cavity increases
Air enters the lungsAir is forced out of the
lungs

13. The breathing mechanism
Balloon expand
Balloon contract
Bell jar
Glass tube
Rubber sheet

14. •Bell jar = rib cage
•Balloons = lungs
•Rubber sheet = diaphragm
•When rubber sheet is pulled downwards, air
pressure inside bell jar is lowered. Balloons
expand
•When rubber sheet is pulled upwards, air
pressure inside bell jar increased. Balloons
contract

15. Transport of oxygen in the human
body
•Involve the following process
–Diffusion of oxygen from the alveoli into blood
capillaries
–Transport of oxygen by red blood cells
–Diffusion of oxygen from the blood capillaries into
cells
•Oxygen –diffuse from alveoli to the blood
capillary
•Carbon dioxide -diffuse from blood capillary to
the alveoli

17. •Oxyigen are not soluble in red blood cell
•red blood cell contain pigment -haemoglobin
red in coloured
•Oxygen will combine with haemoglobin
•Haemoglobin + O2-> O2Hb(oxyhaemoglobin)

18. Importance of healthy respiratory
system

19. Effect of smoke to respiratory
system
•Cigarette smoke contains irritants chemical :
•Acarcinogen-an agent directly involved in
causing cancer.
•Nicotine –cause addicted
•Carbon monoxide –cause death
•Sulfur oxide –acidic = damages lung tissues
•Tar –blackens the lungs and causes them to be
less efficient for gaseous exchange

20. Bahan –bahan lain yang
merbahaya
•Hasil daripada sisa industri seperti:
–Debu simen
–Debu arang
–Debu asbestos
•Pencemaran daripada asap kenderaan\
–Karbon monoksida
–Hidrokarbon-karsinogenik
–Nitrogen oksida –hujan asid

21. Masalah pernafasan
•Bronkitis-sejenis keradangan atau
kerengsaan pada saluran pernafasan (tiub
bronkiul) di dalam paru-paru.
•Asma -sejenis penyakit paru-paru yang
terjadi akibat radang dan penguncupan
saluran pernafasan.
•Kanser paru -paru