Pulmonary function tests, PFTs, Lung Function tests, lung volume tests, lung flow tests, diffusion capacity, airway reactivity, compliance, resistance, conductance, tidal volume, inspiratory capacity, inspiratory reserve volume, expiratory reserve volume, slow vital capacity, residual volume, total lung capacity, lung capacities, forced expiratory volume, peak expiratory flow rate, forced expiratory flow, FEV, PEFR, FEF, effects of pulmonary diseases on PFTs, spirometry, spirometer, differences between lung volume and capacities