Tongue. False-colour scanning electron micrograph of part of the dorsal surface of the tongue. It is mostly covered by conical-shaped filiform papillae which have mechanical and tactile functions. Three round fungiform papillae are also seen. Filiform papillae are covered by epithelial cells apart from their tips (white) which are formed by the fibrous protein keratin which increases the papillae's strength. Fungiform papillae appear redder because of the numerous blood vessels in the underlying connective tissue. Taste buds (not seen) are usually found on their surface. Magnification: x70 at 6x7cm, x35 at 35mm size. Magnification: x105 at 4x5 inch size.