1. Respiratory system
Exercise Physiology

3. Inhalation Nasal cavity Hairs: filter air Mucus: filters & moistens
Blood vessels: warm air
• Pharnyx (throat)
• Larynx (voice box)- glottis, epiglottis
• Trachea (wind pipe)- mucus & hairs.
cartilage rings maintain shape.
•Bronchi- Lungs (Bronchioles, alveoli)

4. Mechanics of breathing- Inhaling
Pleural fluid- between lungs & chest wall
two layers stick together during inhalation
• Ribs move up and out b/c of external
intercoastal muscles
• Diaphragm- contracts downward.
• as all the above happen the pressure inside
the chest cavity drops & air flows in.
diaphragm & ribs movement
Path of air in respiratory tract

5. Mechanics of breathing- Exhaling
Passive process
Diaphragm relaxes & goes back up forcing air out
Forces exhalation requires use of other muscles.
(internal intercoastal muscles pec major,
minor, traps, rhomboids)
Respiration inhale - exhale 9min

6. Diffusion- Pressure differences
Passive transport of gases
High to low pressure
Higher pressure in lungs (alveoli) than in capillaries.
Higher pressure in blood vessels than in cells of tissues
CO2 metabolic waste carried to lungs – diffuses into vessels and into lungs.

7. Oxygen Transport Transported 2 ways: Attached to hemoglobin - 98.5%
Dissolved in blood plasma – 1.5%
• Hemoglobin – contains iron, binds to oxygen.
- oxyhemoglobin (with oxygen)
- deoxyhemoglobin (without oxygen)
- binding, unbinding- occurs in lungs

8. CO2 Removal Diffuses into blood stream then into alveoli
3 forms of Carbon dioxide
Bicarbonate ions 70%
Bond to hemoglobin 23%
Dissolved in plasma 7%
gas exchange in respiratory system 8min

9. What controls gas exchange?
Bohr Effect- O2 levels in blood
if the pH was lower than normal (normal physiological pH is 7.4), then hemoglobin does not bind oxygen as well.
Lactic Acid & Carbonic Acid build up in blood- cause pH to be lower ( become more acidic)
● Respiration is controlled by the medulla oblongata