(via The human heart stripped of fat and muscle, with…)
UPDATE, via sexartandpolitics! this is not a human heart, it is a porcine heart:
“This is the vasculature of an actual heart (porcine heart, identical to human heart). The blood is replaced by a plastic substance which fills all of the veins, capillaries, etc, then the heart is put into a solution that dissolves all the tissue, leaving this incredible detail of a heart.” (glockoma on flickr)