Vestibular Sensory Organs: A Scanning Electron Microscopic Investigation

Using the scanning electron microscope and freeze-drying techniques, the vestibular organs (utricle, saccule, and crista ampullaris) of various experimental animals were examined with results showing that directional arrangement of sensory hairs polarize along the striola. In the utricle, they face each other along the striola, whereas in the saccule, they face away from each other. The sensory hairs in both saccule and utricle are shorter than in the crista ampullaris. The otolithic membrane in the utricle and saccule possesses oval or honeycomb-like holes along the striola. In the cupula, tubules were found with opened top portions. In both the otolithic membrane and cupula, the sensory hairs were not totally embedded in gelatin as was postulated; rather, only the longer hairs were touching the otolithic membrane.