stereocilium

(= stereocilia (plural) )

Microfilament bundle-supported projection, several microns long, from the apical surface of sensory epithelial cells (hair cells) in inner ear: like a microvillus, but larger. It is stiff and may act as a transducer directly, or merely restrict the movement of the sensory cilium (which does have an axoneme). Also described on cells of pseudo-stratified epithelium of the epididymal duct. Recently, stereocilia have been referred to as stereovilli, a much better and less confusing name.