These ducts have the same confi guration as the semicircular canals. Sensory receptors are found in the ampullae of semicircular ducts as transverse thickening called crista ampullaris.
Crista ampullaris is similar in structure to macula, but the glycoprotein layer is very thick and conical in shape in cross section. It is called cupula (Fig.). There are no crystalline bodies in the cupula. Crista is sensitive to angular movement of head (changes in rotational velocity). It is an organ of kinetic balance (movement sense).