This laboratory exercise consists of three parts, each exploring aspects of the control of breathing. Please do not perform these exercises if you have any respiratory disorders (such as asthma). Part...

This laboratory exercise consists of three parts, each exploring aspects of the control of breathing.
Please do not perform these exercises if you have any respiratory disorders (such as asthma).

Part A: The Effect of Exercise on the Rate of CO2Production

Please read the following instructions for part A. These are the steps we would have completed in lab on campus.You will not perform these steps at home, but you should know how to set up the experiment so you can analyze the given results.

1. Fill a beaker with 200 ml of distilled water. Add 5.0 ml of 0.1N NaOH (to make the solution alkaline) and two drops of phenolphthalein (pH indicator). This indicator is pink in alkaline solutions and clear in neutral or acidic solutions.


2. Divide the solution equally into two beakers.


3. Have the subject put on goggles. While sitting quietly and breathing normally, have the subject inhale from room air but exhale each breath through a straw into the solution in one of the beakers. Do not let air exit through the nose; subject should pinch their nose shut.Do not exhale forcefully– each exhalation should be a normal, tidal exhalation. Record the time it takes to turn the solution from pink to clear.
   
   
   
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4. Have the same subject exercise vigorously for several minutes. Then, inhale from room air and exhale each breath through the straw into the solution in the second beaker. Record the time it takes to turn the solution from pink to clear.


5. 
   Sample data has been provided in the table below. Use this data to answer the questions on your Post-lab assignment.
   

Part B: The Role of CO2in the Regulation of Ventilation

1. Read the entire exercise first.You can complete these breathing exercises yourself, or recruit a family member to act as your subject.
   Your subject should not have any respiratory disorders or be averse to feeling dizzy.
   


2. Take a deep breath, pinch your nose shut and hold your breath for as long as possible. Time the breath hold. Repeat three times, resting between each attempt. Calculate an average, and record the average time in the table below.


3. Hyperventilate for approximately one minute - that is,breathevery deeplyat about 15 breaths/min. Note that you shouldnotbreathe rapidly, but you shouldbreathe deeply.You will probably become somewhat dizzy (due to cerebral vasoconstriction) and it will become increasingly difficult to breathe deeply. Next, take a deep breath and hold your breath for as long as possible. Time the breath hold and record the time in the table below.


4. Rest until you are comfortable and are breathing normally. Exercise vigorously for approximately 2 minutes, then immediately hold your breath for as long as possible. Time the breath hold and record the time in the table below.

Part C: Changes in the Rate and Depth of Ventilation

You can complete these breathing exercises yourself, or recruit a family member to act as your subject.
Qualitativelydescribe observations and changes in breathing patterns (inhalation and exhalation) while the subject completes the following tasks:

• Read aloud for at least 30 seconds


• Cough once or twice


• Thread a needle for at least 30 seconds