This image of neurons growing over astrocytes in a human stem cell embryo body – taken by Dr Juan Carlos Izpisúa of the Centre of Regenerative Medicine in Barcelona – was one of the Images of Distinction in the Nikon Small World 2011 competition
Each kidney contains thousands of glomeruli, tiny knots of blood vessels that filter large molecules out of urine. Fractal branching patterns in the circulation of blood inside the kidney ensure that the filtration process is as efficient as possible.
Color-enhanced scanning electron micrograph of the inside of a guinea pig inner ear showing the hearing organ, or cochlea. Running along the spiral structure are rows of sensory cells which respond to different frequencies of sound.