Final answer:
During hyperventilation, PO2 levels increase and PCO2 levels decrease due to an increased ventilation rate that doesn't match the body's production of carbon dioxide, leading to decreased CO2 levels in the blood.
Step-by-step explanation:
During hyperventilation, the PO2 levels increase and PCO2 levels decrease. Hyperventilation is a condition characterized by an increased ventilation rate that exceeds the body's production of carbon dioxide, which leads to a decrease in the blood levels of CO2 (hypocapnia) and can result in increased blood pH (alkalosis). This contrasts with hyperpnea, an increased depth and rate of ventilation in response to increased oxygen demand, which does not significantly alter the blood levels of oxygen or carbon dioxide.
In the systemic capillaries, blood loses oxygen and gains carbon dioxide due to pressure gradients between the blood and the tissues. The venous PO2 decreases as oxygen diffuses out of the capillaries into the tissue cells, and PCO2 increases as carbon dioxide diffuses from the tissue cells into the blood, ready to be expelled in the lungs. However, during hyperventilation, this balance is disrupted causing the individual to expel carbon dioxide at a faster rate than it is produced, thus lowering the PCO2 levels in the blood while increasing the PO2.