A tattoo machine causes a wound that alerts the body to begin the inflammatory process, calling immune system cells to the wound site to begin repairing the skin. It is this very process that makes tattoos permanent.

From the TED-Ed Lesson What makes tattoos permanent? - Claudia Aguirre

Animation by TOGETHER

Awesome shot of a healing wound 

Coloured scanning electron micrograph (SEM) of a healing wound on the skin. There are red blood cells (erythrocytes) on the skin’s surface.

Keratinocytes (skin cells that contain the protein keratin, centre) are forming a hard protective layer (scab) over the wound.

Magnification x400, by Steve Gschmeissner

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