Semi-circular canals are associated with

Each semicircular canals has an enlargement at one of its ends called the ampulla, and the ducts and ampulla are filled with a fluid called endolymph. Flow of the fluid through one of the ducts and through its ampulla excites the sensory organs of the ampulla. In each ampulla a small crest called crista ampullaris is present. On top of crista is cupula. Into the cupula are projected hundreds of cilia from hair cells where bending of cupula in one direction causes repolarization of the hair cells, whereas bending it in the opposite direction hyperpolarises the hair cells. Then from the hair cells, appropriate signals are sent by way from the vestibular nerve to apprise the central nervous system of a change in rotation of head and rate of change in each of the three planes of space. REF: TEXTBOOK OF MEDICAL PHYSIOLOGY GUYTON AND HALL, 12e Page no 790, 791.