A living human brain. Looks gross. But think about how amazing this is. You have one of these things inside your head, a mass of organic matter in which billions of connections make you — every memory, everything that ever was in your life is inside this mass.
The photo was taken Robert Ludlow — of the Institute of Neurology at the University of Central London — while operating a patient to treat his epilepsy. It won the Wellcome Image Award two years ago. [Sploid]