airway resistance alveolar-arterial gradient alveolar gas equation apneustic center arterial blood gas bicarbonate body plethysmography bohr effect bronchial challenge test bronchial hyperresponsiveness bronchoconstriction bronchodilator carbon dioxide carbonic acid carbonic anhydrase central chemoreceptors chemosensor chloride shift closing capacity control of respiration dlco dead space diffusion capacity dorsal respiratory group emedicine effects of high altitude on humans emphysema exhalation functional residual capacity gas exchange hemoglobin hering-breuer reflex human physiology hypoxic pulmonary vasoconstriction hysteresivity inhalation john scott haldane lung volumes medical college of georgia medulla oblongata oxygen oxygen-haemoglobin dissociation curve oxygen toxicity peak flow meter peripheral chemoreceptors physician pneumotaxic center pons positive pressure ventilation protein proton pulmonary circulation pulmonary compliance pulmonary gas pressures pulmonary shunt pulmonary stretch receptors pulmonary surfactant respiratory minute volume respiratory physiology respiratory quotient respiratory rate respiratory system respirometer scottish people spirometry tidal volume ventral respiratory group vital capacity zones of the lung