1. Respiratory System Anatomy and Physiology Review Part II
Diana Jones
Paramedic

2. Respiratory System Important Terms to Know
Tidal Volume
Inspiratory Reserve Volume (IRC)
Expiratory Reserve Volume (ERC)
Total Lung Capacity
Functional Residual Capacity
Residual Volume
Vital Capacity
Dead-space Volume
Functional Volume
Minute Volume

3. What Drives the Respiratory System?
Carbon Dioxide
Detected by chemoreceptors
Increase in CO2
Increase in ventilation
Decrease in CO2
Decrease in ventilation
So what happens with COPD patients???

4. Normal Respiratory Rates
Adults – 12 to 20 per min
Children – 18 to 24 per min
Infants – 22 to 36 per min
Newborns – 40 to 60 per min

5. Factors Influencing Respiratory Rate
Fever
Drugs – depressants and stimulants
Anxiety
Sleep
Oxygen/CO2 level
Disease

6. Tidal Volume
Tidal Volume (VT) – when at rest, the volume of air in 1 respiratory cycle (inspired and expired)
Normal adult is 500mL of air

7. Inspiratory Reserve Volume
Inspiratory Reserve Volume (IRV) – amount of additional air forcibly inhaled after inspiration of normal tidal volume
Varies by sex
Up to 3100mL

8. Expiratory Reserve Volume
Expiratory Reserve Volume (ERV) – amount of additional air forcibly exhaled after expiration of normal tidal volume
Approximately 1200mL

9. Residual Volume
Residual Volume – volume of air remaining the most forcible expiration
Approximately 1200mL

10. Vital Capacity
Vital Capacity (VC) – total amount of air that can be expired after a full inhalation
Can be affected by age and body size
Approximately 4800mL

11. Dead-space
Dead-space Volume – volume that remains in the airways (ex. Trachea, bronchi) and never reaches site for gas exchange
Approximately 150mL of tidal volume

12. Functional Volume
Functional Volume – air that reaches the alveoli and participates in gas exchange
Approximately 350mL of tidal volume

13. Functional Residual Capacity
Functional Residual Capacity (FRC) – amount of air remaining in the lungs after a normal expiration
Approximately 2400mL

14. Total Lung Capacity
Total Lung Capacity – maximum amount of air that can fill the lungs
Approximately 6L

15. Minute Volume
Minute Volume (VE) – total volume of air exhaled per minute
Product of RATE x VOLUME; f x VT = VE
Approximately 6L/min

16. Minute Volume Homeostatic mechanism
Maintenance of PaCO2 (blood carbon dioxide)
Critical significance in the mechanically ventilated patient
How would hyper or hypoventilation cause a shift in minute volume (remember the formula)

17. Important Measures Pulse Oximetry End-tidal CO2
Measures the amount of oxygen in the blood
Given as percent of hemoglobin saturated
Used only as a tool
What could be wrong the reading
Normal is 95 to 100%
Detects carbon dioxide in a gas sample using infra-red light
Commonly recognized as “gold standard” for intubation confirmation
Provides wealth of additional information
Be on the lookout for separate lecture

18. Questions?