Ventilation-perfusion inequality

Ventilation-Perfusion Inequality (also known as Ventilation-Perfusion Mismatch) is when certain groups of alveoli experience a decrease in ventilation which causes a higher concentration of carbon dioxide (CO₂) and a lower concentration of oxygen (O₂). The inequality refers to the fact that perfusion has remained constant, the amount of blood flowing to and from the healthy alveoli and unhealthy alveoli is still the same. The body's natural reaction to this is to constrict the pulmonary arterioles that lead to the unhealthy alveoli; by doing this, the body increases the amount of blood travelling to healthy alveoli. This is generally caused by hypoxic conditions or asthma.