Hair shaft and skin. Coloured scanning electron micrograph (SEM) of a hair shaft (dark brown, left) growing from the surface of human skin. A hair shaft grows from a hair follicle (not seen) below the surface of the skin. Hair is made up of a fibrous protein called keratin. The outermost skin layer, the stratum corneum, also consists of keratinized dead cells (light brown) that are here detaching from the body. The squamous (flattened) cells that make up the stratum corneum arise from the lower, living layers of skin. Magnification: x167 at 6x7cm size.