STEP 1. The first thing you want to do is draw a line for the wind pipe, and then two branch lines that will connect to the shapes of the lung pieces.   STEP 2. Here you will begin drawing the shape of the windpipe which looks like your back bone. Be sure to add the cross lines for texture and detailing.   STEP 3. Thicken and weld the shapes of the lungs like you see here, and then add some detailing veins like so. Erase the guidelines and shapes you drew in step one.   STEP 4. See how easy it was to learn how to draw lungs. Now all you have to do is color them in. Now that you have a nicely drawn sketch of the human lungs, you are ready to pieces together your bodies anatomy.