At the BODIES exhibition in Las Vegas I saw real human hearts, brains and a forest of blood vessels. Here's what surprised me, and the question I couldn't stop asking.
Everything at BODIES...The Exhibition was once a real person, preserved so it won't decay. It was quiet, a bit strange, and the best science lesson I've had.
## The sound isn't the squeeze
I always thought a heartbeat was the sound of the heart squeezing. It's actually mostly valves snapping shut: "lub" when the valves between the chambers close, then "dub" a split second later when the valves out to the body and lungs close.
## A forest made of blood vessels
In a dark room, glowing cases held only the blood vessels of an arm or a liver. They were filled with coloured plastic that hardened, then everything else was dissolved. They look like coral. Laid end to end, one adult's vessels would stretch roughly 100,000 km.
## The question I couldn't stop asking
The bodies are said to have come from China, from people whose bodies were not claimed. Some people have questioned whether they ever agreed to this. Other exhibitions only use people who chose to donate. I think consent is the most important question in the building.