So, the outer membrane region has the hydrophobic heads pointing towards the surroundings and the hydrophobic tails pointing inwards. The inner membrane, this section here, has the hydrophobic tails pointing away from the polar cytosol and the hydrophilic heads pointing towards that polar cytosol. So this is our arrangement here. Now, the next question is what else do we have inside the cell membrane? So it turns out we not only have phospholipids, we also have proteins. And proteins give the cell membrane its functionality, as we'll see in just a moment.