1. Process
of Breathing
“movement of air from outside the body to the lungs”
Diaphragm is the principle muscle in controlling breathing  upon stimulation, will contract

2. Air outside  Air inside
PRESSURE CHANGES
High pressure  Low pressure
Pleural membrane covers lungs and allows smoother movement

3. Automatically So how do we breath? Diaphragm contracts (moves down)
Chest increases in size (intercostal muscles)  air space increases
Decrease in pressure in the lungs
.: Pressure outside body > inside body
Air rushes in
Automatically
INHALATION (active process)
EXHALATION (passive/active)
Diaphragm relaxes
Chest decreases in size  air space decreases
Increase in pressure in the lungs
.: Pressure outside body < inside body
Air rushes out
Forced breathing
Quiet breathing

5. Ventilation at maximum?
Ventilation (VE )
“The volume of air that is moved in 1 minute.”
Air in and out
VE (L/min)= VT (L) x f (breaths/min)
Tidal Volume
volume of air in each breath
rest = 0.5 L/min
max = 3-4 L/min
Respiratory frequency
number of breaths per minute
rest = 12 breaths/min
max = breaths/min
Ventilation at maximum?

6. Lung Capacity Spirometer
Depends on: sex, body type, and lifestyle
Spirometer
Using your textbook (page 443) label, name and define the 6 short forms above

7. Lung Volumes TLC = VC + RV Static vs Dynamic
So we’ve got the air to the lungs. . .
Lung Volumes
Static vs
Dynamic
-volumes determined by structure of lung
-volumes dependent on movement of air
TLC = VC + RV
Total Lung Capacity
max air lungs hold
Vital Capacity
max air exhaled following max inhale
Residual Volume
remaining air in lungs after max exhale

8. Oxygen Usage VO2: mVO2 VO2max mVO2 = 15 HRmax HRmin
rate at which oxygen is used by the body
-measured in mL/kg/min
mVO2 VO2max
-measure of efficiency of the respiratory system
How do we calculate?
mVO2 = HRmax
HRmin
220-age

10. O2 Transport 2% dissolved in plasma
VAST majority binds to hemoglobin (1.34 ml of O2 per molecule)
OXYHAEMOGLOBIN DISSOCIATION CURVE
-Percent saturation of hemoglobin (SbO2%)
-Pressure of oxygen in the blood (PO2)
What does this graph illustrate?
The lower the PO2, the less O2 will bind to hemoglobin

11. Your turn,
In your own words discuss what effect ALTITUDE has on respiration. Read page 449 in your textbook to help with your understanding.