1. The Respiratory System

2. The Respiratory System is all about...
Gas Exchange
Air Pressure

3. Pre-Knowledge Check-In
Find a Partner and See if you can fill in this chart
And now the answers
GAS N2 O2 Ar
CO2
INHALED
78%
21%
~1%
0.03%
EXHALED
16% 5%
GAS N2 O2 Ar
CO2
INHALED
EXHALED

4. Resting (Between Breaths)
What is the air pressure inside the lungs?
What muscles are working at this stage?
How do the ribs protect the lungs?
How are the Brain and the Circulatory System involved?

5. Inhalation What is the air pressure inside the lungs?
What muscle(s) are working to help inhale?
How do the ribs help expand the lungs?
What is the Circulatory System doing at this point?

6. Exhalation What is the air pressure inside the lungs?
What muscle(s) are contracted during exhalation?
How do the ribs help exhalation occur?
What is the circulatory system pushing out of the body during exhalation?
In all these steps when do lungs contract/expand?