Nasal epithelium. Coloured scanning electron micrograph (SEM) of the lining of the nasal cavity. The nasal cavity contains both ciliated and non-ciliated (secretory) cells. The cilia (hair-like, pink) help to move mucus (produced by secretory cells) and foreign bodies away from the respiratory tract and towards the pharynx in the throat, where it can be swallowed. Magnification: x800 when printed 10cm wide.