Ear canal. Coloured scanning electron micrograph (SEM) of wax and debris in an ear canal. The ear canal runs between the outer ear and the eardrum. Wax, or cerumen, is produced by glands in the wall of the ear canal. It prevents the entry of bacteria and foreign objects that could damage the ear. The debris consists of shed skin cells and dirt. Magnification: x160 when printed 10 centimetres wide.