As I posted above, Zygote is the only make of detailed medical models that we have ever come across.  They are static so you would have to do any rigging yourself.  Add to that the high poly count.  I somewhat understand the desire of ultra detailing your scene of a city street but where does the the model of the circulatory system fit it?  Are you looking for detailing in skin vascularity?  Zevo has some vascular overlays both at Rendo and DAZ.  Also take a look at Corinthianscori's products at Rendo.  He has some textures that use layering to show the underlying blood vessels in the skin.