Smell receptor. Coloured transmission electron micrograph (TEM) of a section through the olfactory (smell) epithelium of the nose. At centre (orange) is an olfactory receptor cell body. At its top two long, modified non-motile cilia project into the liquid lining of the nasal cavity. The cilia are thought to be the sites of interaction between odiferous substances and the receptor cells. Surrounding the receptor cell are the supporting cells with surface microvilli (finger-like). Within the cells, mitochondria (purple) & endoplasmic reticulum (flattened sacs) are seen. Magnification: x2,130 at 6x7cm size. Magnification: x7,300 at 10x8 inch size.