Final answer:
The statement is false; a low VA/Q ratio leads to vasoconstriction, but it also causes bronchoconstriction, not bronchodilation, to reduce mismatch by diverting air to well-perfused areas.
Step-by-step explanation:
The statement "A low VA/Q ratio results in both vasoconstriction and bronchodilation" is false. VA/Q ratio stands for ventilation/perfusion ratio, which is a measure of the efficiency and adequacy of the matching of ventilation (airflow) to perfusion (blood flow) in the lungs. When the VA/Q ratio is low, it typically indicates poor ventilation relative to perfusion. The body responds to low VA/Q ratios with vasoconstriction to redirect blood flow to better-ventilated areas of the lung. However, instead of bronchodilation, we actually see bronchoconstriction in areas of low ventilation to reduce the mismatch by diverting air to better-perfused areas of the lungs.