The impact of gravity on pulmonary perfusion expresses itself as the hydrostatic pressure of the blood passing through the branches of the pulmonary artery in order to reach the apical and basal areas of the lungs, acting synergistically with the pressure developed by the right ventricle.
The force of gravity affects blood flow to the lungs through hydrostatic pressure within the pulmonary artery's branches, which spreads evenly across the lung's upper and lower areas, complemented by the pressure created by the right heart chamber.