Exploring Various Breathing Patterns
You will establish the baseline respiratory values in the first part of this experiment. 1. If the grid in the data control unit is not empty, click Clear Table to discard all previous data. 2. Adjust the radius of the airways to 5.00 mm by clicking the appropriate button next to the Radius window. Now, read through steps 3–5 before attempting to execute them.
3. Click Start, and notice that it changes to Stop to allow you to stop the respiration. Watch the simulated lungs begin to breathe as a result of the external mechanical forces supplied by the pump below the bell jar. Simultaneously, the oscilloscope will display a tracing of the tidal volume for each breath. 4. After 2 seconds, click the Hyperventilation button and watch the PCO2 displays. The breathing pattern will change to short, rapid breaths. The PCO2 of the air in the lungs will be displayed in the small window to the right of the Hyperventilation button. 5. Watch the oscilloscope display and the PCO2 window, and click Stop before the tracing reaches the end of the screen. What happens to PCO2 during rapid breathing? Explain your answer.
6. Click Record Data.
7. Now click Clear Tracings to prepare for the next run.
When Rebreathing is clicked, a small bag will appear over the end of the air tube to allow the air within the lungs to be repeatedly inspired and expired.
1. Click Start, wait 2 seconds, and then click Rebreathing.
2. Watch the breathing pattern on the oscilloscope, and notice the PCO2 during the course of the run. Click Stop when the tracing reaches the right edge of the oscilloscope.
What happens to PCO2 during the entire time of the rebreathing activity?
Did the depth of the breathing pattern change during rebreathing? (Carefully examine the tracing for rate and depth changes; the changes can be subtle.) Explain your observations.
3. Click Record Data, and then click Clear Tracings to prepare for the next run.
Breath holding can be considered an extreme form of rebreathing in which there is no gas exchange between the outside atmosphere and the air within the lungs.
1. Click Start, wait a second or two, and then click Breath Holding. 2. Let the breath-holding activity continue for about 5 seconds, and then click Normal Breathing. 3. Click Stop when the tracing reaches the right edge of the oscilloscope.
What happened to the PCO2 during breath holding?
What happened to the breathing pattern when normal respirations resume?
4. Click Record Data.
5. Click Tools →Print Data to print your data.
In Activity 1, normal respiratory volumes and capacities are measured. In this activity, you will explore what happens to these values when pathophysiology develops or during episodes of aerobic exercise. Using a water-filled spirometer and knowledge of respiratory mechanics, changes to these values in each condition can be predicted, documented, and explained.
1. Click the Experiment menu, and then click Comparative Spirometry. The opening screen will appear in a few seconds (see Figure 7.4). 2. For the patient’s type of breathing, select the Normal option from the drop-down menu in the Patient Type box. These values will serve as a basis of comparison in the diseased conditions. 3. Select the patient’s breathing pattern as Unforced Breathing from the Breathing Pattern Option box. 4. After these selections are made, click the Start button and watch as the drum starts turning and the spirogram develops on the paper rolling off the drum across the screen, left to right. 5. When half the screen is filled with unforced tidal volumes and the trace has paused, select the Forced Vital Capacity button in the Breathing Pattern Options box.
6. Click the Start button and the trace will continue with the FVC maneuver. The trace ends as the paper rolls to the right edge of the...