1. Respiratory System

2. *RESPIRATION: intake of O2 and discharge of CO2
*Blood is the transport vehicle
*Lungs: internal gas exchange area

3. *PATH:
Inhale air through nose/ mouth
Passes to pharynx
Then goes into trachea (“windpipe”):
*tube which conducts air from outside to lungs
*protected by epiglottis (covers trachea during eating)

4. Branching from trachea– 2 large tubes= bronchi which lead into lungs
These branch many times– end as numerous, small moist sacs (alveoli)
*Gas exchange takes place here
*blood rich in CO2 reaches alveoli through capillaries from pulmonary arteries

5. *During gas exchange:
CO2 diffuses & is exhaled
O2 diffuses & enters blood (hemoglobin)
*Exchange takes place again in tissues (opposite, though)

6. *BREATHING: inhale/ exhale
*movement of air
*INHALATION:
1. requires action of rib muscles and diaphragm (contract)
2. Diaphragm muscles pull down, ribs move up and out–
expands chest cavity
3. Lungs hold about 500 mL of air
4. Muscles then relax, decreasing size of cavity
**nerves/ brain stimulate this process
**increases during exercise

7. Take a deep breath...
Your notes are done!