Like branching plants, the body uses fractals to maximize both surface area and flow. This helps gas and flu exchange in organs like lungs, veins and and intestines. Using various seeds above, you can see that neurons are also fractals: that increases their connectivity. Fractal dimension measures can diagnose problems in lungs, blood vessels, eyes, bone density, cancer cells and tumor growth. Bioengineers use fractals to create an artificial "scaffolding" of biodegradable polymers, so that they can grow replacement tissue that is densely filled with blood vessels.