At birth, what factor causes dilation of the pulmonary vascular bed and a decrease in the pulmonary vascular resistance?

Question

Quizplus · Accepted Answer

With inflation of the lungs and the beginning of their participation in gas exchange, PaO₂ increases and PaCO₂ decreases, both of which contribute to dilation of the pulmonary vasculature and a resultant reduction in pulmonary vascular resistance (PVR). This leads to reduced right ventricular pressures and increased pulmonary blood flow.

At Birth, What Factor Causes Dilation of the Pulmonary Vascular