Nerve fibres. False-colour scanning electron micrograph of a bundle of motor nerve fibres (blue). The bundle as a whole is surrounded by a cylindrical sheath of connective tissue, also known as the epineurium, which is partly visible at extreme right (soft brown). The epineurium has been opened to show the nerve fibres and a few capillaries (violet). Each fibre is surrounded by a thick myelin layer, mostly formed by lipid material, which derives from the Schwann cells. Through these fibres messages are sent from the brain to the muscles with a maximum speed of 100m per second. Magnification: x 500 at 6x7cm size. x780 at 4x5"~LANDSCAPE"