Gas Exchange in the
Human Body
By Max Mar
8C Science Mrs. Hennard
The Start of the Gas
Exchange
INHALING
The start of the gas exchange
is inhaling. This is when you
breathe in through your
mouth or nose.
When the air is breathed in
through the mouth it travels
down the trachea to the bronchi.
In the Lungs
 After reaching the bronchi, the air is split between the
two lungs. Then the air flows in to the lungs and enters
the bronchiles, then is split between the alveoli…
What are the Alveoli
The air travels to the bronchioles.
It is then spread to the Alveoli
are small
sacks in the lungs
that have blood
cells running
through them. Alveoli are
named after the Latin
word for
‘grapes’
Inside the Alveoli
 Inside the Alveoli is where the gas is exchanged. The
oxygenated air enters the alveoli from the lungs and the
oxygen travels through a one-cell thick
wall of the capillaries to
the veins
and is then
taken to the heart,
oxygenated.
Inside the Alveoli Cont.
 Then the left over carbon dioxide (CO2) is transported
out of the alveoli and taken back out of the lungs. Then
it is exhaled and more air is inhaled and the hole process
starts again
The Air we Breathe
 The air we breathe is made up of 4 main gases
 Approximately 78% Nitrogen
 Approximately 20% Oxygen
 Approximately 1% Argon
 <1% Carbon Dioxide
 <1% A combination of numerous other gases
Bibliography
"Lungs Renovated in Lab." Discovery News. N.p., n.d. Web. 5 Oct. 2012.
<http://news.discovery.com/tech/lungs-reseeding-transplant.html>.
"Alveoli." Alveoli. N.p., n.d. Web. 7 Oct. 2012.
<http://oac.med.jhmi.edu/res_phys/Encyclopedia/Alveoli/Alveoli.HTML>.
"The Respiratory System." : Gas Exchange. N.p., n.d. Web. 9 Oct. 2012.
<http://christylearningcentre.blogspot.com/2010/11/gas-exchange.html>.
"The Trachea and Bronchi." - Gray's Anatomy of the Human Body. N.p., n.d. Web.
9 Oct. 2012.
<http://education.yahoo.com/reference/gray/subjects/subject/237>.