But this tiny region will point to the aqueous environment and it will interact with the nearby heads of those phospholipid molecules because the heads consist of the phosphate groups and sometimes the alcohol molecules that contain those polar regions. So the hydroxyl group, being a polar region, basically interacts with the hydrophobic heads of the phospholipids in that cell membrane and therefore it points towards the aqueous environment. And the rest of the cholesterol molecule, the four fuse rings, as well as this hydrocarbon chain. The tail will basically lie inside the membrane and will be parallel with respect to the nonpolar tails of those phospholipids. Now, to see what we mean by all that, let's take a look at the following diagram. A two dimensional image of our cell membrane, found typically, let's say, in eukaryotic cells, such as our own cells of the body.