explain how oxygen moves across from the lungs into the blood? how are the lungs adapted for this?

via diffusion down a concentration gradient as O2 levels are higher in the lungs than in the blood. for faster diffusion you need:a large surface area (lungs have million of alveoli which are air filled sacs)a short diffusion pathway (the alveoli are very thin, and capillaries are one cell thick) a steep concentration gradient (there is a fast blood flow in the lungs)