Weird facts about the human body

Image-maker Alexander Tsiaras shares a powerful medical visualization, showing human development from conception to birth and beyond. (Some graphic images.)

As humans, we can perceive less than a ten-trillionth of all light waves. "Our experience of reality," says neuroscientist David Eagleman, "is constrained by our biology." He wants to change that. His research into our brain processes has led him to create new interfaces -- such as a sensory vest -- to take in previously unseen information about the world around us.

Every cell in the human body has a sex, which means that men and women are different right down to the cellular level. Yet too often, research and medicine ignore this insight -- and the often startlingly different ways in which the two sexes respond to disease or treatment. As pioneering doctor Paula Johnson describes in this thought-provoking talk, lumping everyone in together means we essentially leave women's health to chance. It's time to rethink.

Greg Gage is on a mission to make brain science accessible to all. In this fun, kind of creepy demo, the neuroscientist and TED Senior Fellow uses a simple, inexpensive DIY kit to take away the free will of an audience member. It's not a parlor trick; it actually works. You have to see it to believe it.

When you look at sporting achievements over the last decades, it seems like humans have gotten faster, better and stronger in nearly every way. Yet as David Epstein points out in this delightfully counter-intuitive talk, we might want to lay off the self-congratulation. Many factors are at play in shattering athletic records, and the development of our natural talents is just one of them.

What does it take to regrow bone in mass quantities? Typical bone regeneration -- wherein bone is taken from a patient’s hip and grafted onto damaged bone elsewhere in the body -- is limited and can cause great pain just a few years after operation. In an informative talk, Molly Stevens introduces a new stem cell application that harnesses bone’s innate ability to regenerate and produces vast quantities of bone tissue painlessly.

Vilayanur Ramachandran tells us what brain damage can reveal about the connection between celebral tissue and the mind, using three startling delusions as examples.

Anthony Atala's state-of-the-art lab grows human organs -- from muscles to blood vessels to bladders, and more. At TEDMED, he shows footage of his bio-engineers working with some of its sci-fi gizmos, including an oven-like bioreactor (preheat to 98.6 F) and a machine that "prints" human tissue.