man has a pulmonary dism that completely blocks hlood flow to Jeft lung.As a result,which of the olowing will occur? A)Ventilation/perfusion (vio) ratio in the left lung will be zero B) Systemic arterial PO_(2) will be elevated C) Alveolar PO_(2) in the left lung will be approximately equal to the Po2 in inspired air D) VIQ ratio in the left lung will be lower than in the right lung E) Alveolar PO_(2) in the right lung will be approximately equal to the PO_(2) in venous blood

The correct answer is A) Ventilation/perfusion (V/Q) ratio in the left lung will be zero.<br /><br />Explanation:<br />When there is a complete blockage of blood flow to the left lung, it means that there is no perfusion (blood flow) to the left lung. This will result in a ventilation/perfusion (V/Q) ratio of zero in the left lung, as there is no perfusion to the ventilated areas of the lung.<br /><br />The V/Q ratio is a measure of the efficiency of gas exchange in the lungs. It is calculated by dividing the ventilation (air flow) by the perfusion (blood flow). A V/Q ratio of zero indicates that there is no perfusion to the ventilated areas of the lung, which will severely impair gas exchange and lead to hypoxemia (low oxygen levels in the blood).<br /><br />The other options are incorrect:<br />B) Systemic arterial $PO_{2}$ will not be elevated, as the blockage of blood flow to the left lung will lead to hypoxemia.<br />C) Alveolar $PO_{2}$ in the left lung will not be approximately equal to the $PO_{2}$ in inspired air, as there is no perfusion to the left lung.<br />D) The V/Q ratio in the left lung will not be lower than in the right lung, as the left lung has no perfusion.<br />E) Alveolar $PO_{2}$ in the right lung will not be approximately equal to the $PO_{2}$ in venous blood, as the blockage of blood flow to the left lung will not directly affect the right lung.