We have an upper or a superior lobe, and then we have a middle lobe. And the line separating these two lobes is straight, or relatively straight. And that's exactly why we call it the horizontal fissure. Now, we also have a lower lobe, also known as our inferior lobe. And this is separated by a line called the right oblique fissure because it's also slanted, just like this one. So we have the upper, the middle and the lower lobe.