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Related to Otolith organ: utriculus, Saccule and utricle


A calcareous concretion on the end of a sensory hair cell in the vertebrate ear and in some invertebrates.



a solid formation on the surface of the mechanoreceptor cells in the organs of equilibrium of some invertebrates and all vertebrates. Otoliths of different animals vary in origin, size, and structure: they can be secreted by cells or introduced from outside, for example, grains of sand serve as otoliths in crayfish. Mammalian otoliths are usually crystals of calcite (CaCO3) up to 10 microns (μ.) long and 1–3 μ wide.

As otoliths shift in response to acceleration and changes in body position, they mechanically irritate the underlying ciliated receptor cells, which then send appropriate signals to the brain.

The action of otoliths has been demonstrated in experiments with crayfish. The grains of sand that serve as the crayfish’s otoliths were replaced during molting by iron filings, and a magnet was placed above the animal to attract the filings. The crayfish reversed its sense of orientation, turned over, and swam with its abdomen up.


References in periodicals archive ?
Differences in collective otoconial mass between the paired otolith organs could in principle result in asymmetric shear forces on the otolith membranes, although a compensation for asymmetries in vestibular function typically occurs [29].
The otolith organs detect head tilt and linear movement (imagine the sensation of riding an elevator).
When adding power and accelerating during a go-around, especially in more powerful aircraft, the otolith organs in the inner ear send signals to the brain that create the somatogravic illusion of pitching up abruptly.