B5. CIRCULATORY SYSTEM

The human body provides some good examples of fractals in nature. The illustration is of the circulatory system of the lung. Arteries and veins divide and subdivide to form an intricate branching fractal system. The respiratory and neural networks of the body are designed in a similar way.


http://classes.yale.edu/fractals/Panorama/Biology/
                   Physiology/Physiology.html