1. BREATHING AND RESPIRATION

2. The breathing system involves taking in O2 from the air and
releasing Co2 and water vapour back into the air.
The O2 combines with the food we eat to give us energy in
a process called respiration.
The carbon dioxide and water vapour that we breathe out
are waste products of this energy production

4. WHAT IS THE BREATHING SYSTEM?
The nose and mouth take in
the air.
The trachea carries the air
towards the lungs
Nose and
mouth
The bronchus carries the
air into each lung
The bronchioles are thin tubes
which carry air within the lungs
Trachea
Bronchus
The alveoli are surrounded by
blood vessels. O2 and Co2 are
exchanged here.
Bronchioles
Alveoli

6. The functions of the main parts of the Breathing System
Nose
Inhales air
Larynx
Contains the vocal cords that allow speak
Trachea
Made of Cartilage and allows air to pass to and from the lungs
Bronchus
Takes the air to and from each lung
Bronchiole
Carries the air to the alveoli
Alveolus
Exchanges the gases Oxygen IN and Carbon Dioxide OUT of the bloodstream
Diaphragm
A muscle that moves air in or out of the lungs ( in conjunction with intercostal muscles of the ribcage)

7. The Nose We breath through our nose.
Mucous and hairs in the nose trap dirt and bacteria
Air is warmed as it passes through the nose, this helps oxygen pass from the lungs into the bloodstream.

8. Trachea (windpipe)
Air travels through the trachea (or windpipe) as it passes in and out of your lungs.

9. Rings of Cartilage
The trachea is surrounded by several “c-shaped ” rings of a tough material called cartilage.
The cartilage strengthens the trachea so that it doesn’t collapse easily.
Rings of Cartilage

10. The Larynx The larynx (or voice box) is the upper part of the trachea.
The larynx is used to make sounds.
Larynx

11. Bronchus and bronchioles
Near the lungs, the trachea splits into two major branches.
Each one of these branches is known as a bronchus. The bronchi carry air into the lungs.

12. Alveolus Each lung contains millions of tiny air sacs called alveoli.
Each have a thin lining and are surrounded by many tiny blood vessels called capillaries.
Gas exchange occurs here

14. HOW GASEOUS EXCHANGE OCCURS
The exchange of oxygen and carbon dioxide gases is known as
gaseous exchange and this takes place in the lungs.
HOW GASEOUS EXCHANGE OCCURS
The O2 we breathe in diffuses
across the wall of the alveolus
into the blood.
CO2 and water vapour which is a product of
respiration diffuses into the
alveoli from the blood where we
breathe it out.

15. The diaphragm
The Diaphragm is a sheet of muscle at the base of the chest cavity.
The diaphragm causes air to move into or out of our lungs

17. WHAT HAPPENS THE O2 ONCE IT ENTERS THE BLOOD?
The O2 travels through the blood to all the cells of the body.
Here it combines with the food we eat to make energy.
We call this process respiration.

18. Respiration is the release of energy from food

19. Respiration is not the same as breathing!!!!

20. There are two types of RESPIRATION
Aerobic
Anaerobic

21. Aerobic Respiration is the release of energy from food using oxygen

22. To allow aerobic respiration to occur
- glucose is carried to all the cells of the body by the blood
- oxygen is carried from the lungs to all the cells of the body
Each living cell glucose combines with oxygen to release energy
Glucose Energy
+ Carbon Dioxide
Oxygen Water Vapour

24. What is this Molecule?
C6 H12 O6
Answer:
Glucose

25. RESPIRATION

26. Example: Sugars into Alcohol
Anaerobic Respiration is the release of energy from food without oxygen
Example: Sugars into Alcohol

27. EFFECTS OF SMOKING ON THE BREATHING SYSTEM
Tobacco smoke irritates and damages the linings of the
bronchioles
Smoking can reduce the resistance of the lungs to certain diseases
such as bronchitis and lung cancer.
Smoking during pregnancy reduces the O2 available to the
growing baby. This can cause the stunted growth of the baby.
Carbon monoxide gas in cigarette smoke prevents the blood
from carrying O2 properly, this can cause heart strain.

28. STILL NOT CONVINCED?
Healthy lung
Smokers lung

29. How does air enter and leave the lungs?
Diaphragm and intercostals muscles contract, pulling the ribcage down.
The ribcage is attached to the lungs and as a result the volume in the lungs increases causing the pressure to decrease.
Hence air is taken in to balance the pressures when the mouth (or nasal passage) is open.
In order to exhale, the diaphragm relaxes, pushing the ribcage up, reducing the volume of the lungs therefore increasing the pressure, so if the mouth is open air will escape.

31. HOW OTHER ANIMALS BREATHE
Not all animals use lungs for gaseous exchange.
Fish have special organs called gills which absorb the dissolved
O2 in the water
Insects have holes in their outer skeleton called spiracles. O2
simply diffuses through the spiracles to the insect’s cells.

32. SUMMARY
Breathing (gaseous exchange) involves taking in oxygen and releasing carbon dioxide and water vapour.
The human respiration system consists of: mouth & nose, trachea, bronchi, bronchioles, alveoli
Gaseous exchange takes place in the alveoli (in the lungs).
Oxygen combines with food to give us energy in a process
called respiration.
Smoking damages the breathing system.
Insects use a system oh air holes called spiracles for
breathing, fish use gills.

33. Test for CO2
It turns limewater milky.
Test for water
It turns cobalt chloride paper pink / it turns copper sulphate blue

34. To show that there is more carbon dioxide in exhaled air than in inhaled air.
Place equal amounts of clear limewater in two test tubes.
Suck air in through the position shown on diagram A and note that the limewater takes a long time before going milky.
This time exhale air through the top of the tube as shown in diagram B and note that the limewater goes milky quickly.
Conclusion: there is more carbon dioxide in exhaled air.

36. Conclusion
We breath out more CO2 and we breath in.

37. Inhaled
Exhaled
Nitrogen
78%
Oxygen
21%
16%
Carbon dioxide
0.04% 4%
Water vapour
Varies
Much higher

38. Bibliographies Diagram of lungs
Diagram of alveolus
Diagram of healthy lung
Diagram of smokers lung
Diagram of fish
Diagram of insect