Lab Simulation Exercise 7: Respiratory System Mechanics

1.) When you forcefully exhale your entire expiratory reserve volume, any air remaining in your lungs is called the residual volume (RV). Why is it impossible to further exhale the RV (that is, where is this air volume trapped, and why is it trapped?)

This "dead space" of air needs to stay in your lungs constantly; otherwise the lung will completely deflate. If the lung has every bit of air sucked out of it, it will collapse and need to be re-inflated.

2.) How do you measure a person’s RV in a laboratory?

By the air remaining in the lung

3.) Draw a spirogram that depicts a person’s volumes and capacities before and during a significant cough.

Additional Questions for Activity 1.
The following questions refer to Activity 1: Measuring Respiratory Volumes and Calculating Capacitates

1.) What would be an example of an everyday respiratory event the ERV button Stimulates? forced expiration

2.) What additional skeletal muscles are utilized in an ERV activity? abdominal-wall muscles and the internal intercostal muscles contract

3.) What was the FEV1 (%) at the initial radius of 5.00 mm?
73.9%

4.) What happened to the FEV1 (%) as the radius of the airways decreased? How well did the results compare with your prediction?

FEV1 (%) decreased proportionally with the radius

5.) Explain why the results from the experiment suggest that there is an obstructive, rather than a restrictive, pulmonary problem.

The FEV1 (%) decreased proportionally as the radius decreased, characteristic of an obstructive pulmonary problem

Activity 2 Comparative Spriometry

Chart 2: Spirometery Results
Patient Type
TV (ml)
ERV
(ml)
IRV
(ml)
RV (ml)
FVC (ml)
TLC
(ml)
FEV1
(ml)
FEV1 (%)
Normal

500
1500
3000
1000
5000
6000
4000
80%
Emphysema

500
750
2000
2750
3250
6000
1625
50%
Acute asthma attack
300
750
2700
2250
3750
6000
1500
40%
Plus inhaler
500
1500
2800
1200
4800