Using molecular-scale computer simulation, we show that structural changes may take place in phospholipid bilayers in an aqueous solution as we vary the relative concentration of water to phospholipids, the bilayer thickness, the inclination angle of the choline, dipole molecular fragment with respect to the bilayer surface, and the conformation of hydrocarbon chains of phospholipid in the hydrophobic volume of the bilayer. It is shown that in the hydrophobic volume of the bilayer, an interpenetration of the hydrocarbon chains located on opposite sides of the phospholipid bilayer takes place.