1. FUNCTIONING ORGANISMS.
04. Respiratory system.
Saint Ignatius College Geelong
2. RESPIRATORY SYSTEM.
Moving air into & out of our body.
Absorbs oxygen from the air into
Releases carbon dioxide into the air
from the bloodstream.
3. RESPIRATORY SYSTEM.
The site of gas exchange must be:
So that O2 and CO2 can dissolve before moving across the
Have a large surface area.
So that large volumes of gases can move into and out of our
bodies quick enough.
Must be thin & porous.
So that the gases can move across it.
4. RESPIRATORY SYSTEM.
In aquatic organisms such as fish, crustaceans &
molluscs, etc. gas exchange usually occurs across
External respiratory surface.
In direct contact with water & dissolved gases.
No danger of drying out.
5. RESPIRATORY SYSTEM.
In land animals the respiratory surfaces run the risk of
Answer is to make the respiratory surface internal.
e.g. lungs in vertebrates, tracheal system in insects,
visceral cavity (primitive lung) of land snails.
Source: Mason et al.
6. HUMAN RESPIRATORY SYSTEM.
Pathways connecting lungs to
7. HUMAN RESPIRATORY SYSTEM.
We have two lungs in our
Air pathways are a series of
tubes that get narrower and
8. HUMAN RESPIRATORY SYSTEM.
Tiny air sacs at the end
Site of gas exchange.
Surrounded by a rich supply of
Source: Enger et al. (2011)
9. HUMAN RESPIRATORY SYSTEM.
Moist, thin & porous and have a large surface area.
Allows diffusion to occur between the air in the alveoli and
gases in the blood.
O2 from alveoli
10. HUMAN RESPIRATORY SYSTEM.
How we breathe.
The lungs are not muscles!
We rely in our diaphragm
& intercostal muscles to
Source: Sharwood (2005)
11. HUMAN RESPIRATORY SYSTEM.
How we breathe.
Inhalation (breathing in).
Increasing volume of our thoracic
Forcing air in through our air
pathways and into our lungs.
12. HUMAN RESPIRATORY SYSTEM.
How we breathe.
Exhalation (breathing out).
Decreases volume of our thoracic
Forcing air out via our air
pathways into the external
13. WHEN THINGS GO WRONG.
The health of our respiratory system is critical to our
If our respiratory system does not function optimally
then we are unable to deliver oxygen to and remove
carbon dioxide from our blood.
Our cells may also be unable to exchange carbon
dioxide for oxygen, and are therefore unable to undergo
all essential metabolic activities.
Often respiratory illnesses are can lead to other
illnesses, in particular cardiac disease.
14. WHEN THINGS GO WRONG.
Swelling of the bronchi and/or
production of excess mucous,
resulting in constriction the
Main symptom is coughing.
May be caused by colds & flu,
15. WHEN THINGS GO WRONG.
Swelling of the bronchi and
production of excess
mucous, resulting in
constriction of airways.
Symptoms include difficulty
breathing, wheezing, etc.
May be caused by an
overactive immune system
(e.g. allergies), stress, etc. Source: http://www.wymedical.com.au/Asthma-Products.htm
16. WHEN THINGS GO WRONG.
Caused by loss of elasticity to
bronchi and alveoli reducing
exchange of gases.
Symptoms include shortness
of breath, etc.
May be caused by smoking,
long-term exposure to
pollutants or dust.
Enger, E.D., Ross, F.C., & Bailey, D.B. (2011).
Concepts in Biology. New York: McGraw-Hill.
Raven, P.H., Johnson, G.B., Mason, K.H., Losos,
J.B., & Singer, S.R. (2011). Biology. New York:
Russell, P.J., Hertz, P.E., & McMillan, B. (2011).
Biology: The Dynamic Science. Canada: Thomson
Sharwood, J. (Ed.). (2005). Science Edge 2.
Melbourne: Thomson Learning.