Nerve fibres in tongue. Light micrograph of nerve fibres (black) among skeletal muscle (brown) of the tongue. Brown ovals are muscle fibre cell nu- clei. The human tongue consists mostly of a mass of interlacing bundles of muscle fibres that give great dexterity of movement as well as strength. The tongue's principal function is to push food over the teeth during chewing and to form chewed matter into an easily swallowed lump. Abundant mo- tor nerve fibres serve the tongue's muscle cells, while sensory nerve fibres carry impulses from taste buds to the brain. Prepared with Glees stain (Bielschovosky stain). Magnification unknown.