ventilation/perfusion ratio

(redirected from V/Q)
Also found in: Acronyms.

ven·ti·la·tion/per·fu·sion ra·ti·o

the ratio of alveolar ventilation to simultaneous alveolar capillary blood flow in any part of the lung; because both ventilation and perfusion are expressed per unit volume of tissue and per unit of time, which cancel, the units become liters of gas per liter of blood.