The Human Body: Secrets of Your Life Revealed

Photo © BBC / Fleur Bone

Photo © BBC / Fleur Bone

Photo © BBC / Fleur Bone

Photo © BBC / Freddie Claire

Photo © BBC / Freddie Claire

Photo © BBC / Freddie Claire

Photo © BBC / Bryan D. Hughes

Photo © BBC / Robbie Meade

Photo © BBC / Ross Kirby

Photo © BBC / Ross Kirby