For centuries, scientists have explored the internal systems of animals in an attempt to learn more about our origins and genetic relationships. Sketches pulled from Leonardo da Vinci's notebooks show very accurate skeletal and muscular anatomies of horses and men. Those served as the basis of his artwork as well as an outlet for his intellectual curiosity.
At London's Natural History Museum , a new exhibit called Animals Inside Out  indulges mankind's fascination by displaying plastinated animals that use the same technology developed by Gunther von Hagens's for the popular Body Worlds  exhibits. While fiendish at first glance, the displays showcase the intricate architecture of an amazing animal world.
Take a look at these images and then let us know: fascinating or freaky?
The leg muscles of reindeer are concentrated close to the body, leaving the lower legs light and agile, to help these creatures evade predators.
What appears to be an eerily glowing shark is actually the animal's circulatory system highlighted with colored resin.
A trisected horse head shows the skull and brain in cross section.
The largest display, a plastinated Asian elephant, shows the intricate muscular development of the trunk as well as the surprisingly small brain and central nervous system. Nearby, a giraffe seems to have a lot of bones in that long neck, but it actually contains the same number of cervical vertebrae as a human's!
Another view of the elephant and giraffe displays.
Check out the incredible muscle mass on this raging bull! No wonder people want to keep their distance.
At first glance, this shark seems intact, but what you're seeing is really the muscular tissue of the ocean predator.
A display of ostriches show the muscular and circulatory systems of these enormous birds.
A plastinated goat rears up high on a rock.
Another otherworldly display shows the circulatory network in a horse's head.
This plastinated gorilla's exposed muscles demonstrate just how strong our cousin is.
A horse's skull displays the large mandible and flat teeth, perfect for grinding up hay and grass.