Homework #1

1.   (a) Calculate the PO2 of alveolar (wet) at sea level 
         (barometric pressure Pt=760mmHg) containing the 
         normal 14.6% O2.

     (b) Calculate the PCO2 of alveolar air at sea level 
         containing the normal 5.62% CO2.  During short 
         exposure to 18,00 ft (Pt=380mmHg) the alveolar 
         PCO2 falls to 32mmHg.  What % of CO2 is this?
 

2. A subject's basal O2 consumption measured in the spirometer
   (wet, T=22 C, Pt=632mmHg) was 0.4 L/min.

    (a) Find its STPD corrected value.

    (b) If you improperly decide to correct this value to BTPS,
        find its value.  (Note: this error can lead to a 
        misdiagnosis of hyperthyroidism in a perfectly normal
        patient.)

 
3.  A subject sits in a sealed body plethysmograh box with a
    nose clip.
    
    (a) during the breathing cycle, when should the breathing
        shutter be turned off in order to measure his FRC(?)

    (b) if the subject makes an expiratory effort against 
        the shutter, a change of volume and pressure are 
        measured at 20 ml and 8 mmHg, respectively, find the 
        FRC at Pt=760 mmHg and a constant temperature.
 

4.  The O2 diffusing capacity (DO2 ) can be found with low
    concentration breathing of CO.  Now, an exercising subject
    breathes a low concentration of CO in a steady state.
    If the CO alveolar PCO is 0.3 mmHg and the CO uptake is 
    35 ml/min, find the DO2.

Please note that the explicit instructions for how to solve problems #1 and #2 have been on the web now since the first week of class.

For the answers, click here .