Ch 13.2C -- Respiratory Mechanics -- VTPP 435

Ch 13.2C -- Respiratory Mechanics -- VTPP 435

2 General Categories show abnormal results during spirometry

1) Obstructive Lung Disease -- difficulty emptying lungs
2) Restrictive Lung Disease -- difficulty filling lungs

Pulmonary or Minute Ventilation

-volume of air breathed in and out in one minute
-= TV (mL/breath) * Respiratory Rate (breaths/min)
-avg 6000 mL/min

Anatomic Dead Space

-volume of air that stays in conducting airways where it is not available for gas exchange
-avg 150 mL

Alveolar Ventilation

-(TV - dead space) * Respiratory Rate
-more important than pulmonary ventilation
-avg 4200 mL/min

Effect of CO2 on Bronchiolar Smooth Muscle

-CO2 levels increase in alveolus --> bronchodilation
-CO2 levels decrease in alveolus --> bronchoconstriction

Effect of O2 on Pulmonary Smooth Muscle

-O2 levels decrease in alveolus --> vasoconstrict pulmonary arteriole
-O2 levels increase in alveolus --> pulmonary vasodilation