The lungs grow in lobes, with each lobe fed by a stem of the bronchial ‘tree’. A reasonable analogy would be to think of the trunk of the tree as the trachea, branching into two trunks, right and left, and then continuing to subdivide as the branches get smaller, with the aveoli finally comprising the leaves. The pieces are actually separation between the lobes. The left one did have a cut on it that the dialogue refers to (the ‘insult’) but the cut is not visible.
That’s right… Actually, they are grown with the aveolis collapsed. They pop open when respirations start. Also, your right lung has three lobes, while your left only has two, leaving room for your heart.