Question

Describe the physiology of the semicircular canals which enable us to detect rotational motion.

Answer 1

The semicircular ducts will act as a sensory receptor for the rotation movements.

Semicircular canal is filled with a fluid referred to as endolymph and contains movement sensors in the fluids. At the base of each canal, the bony place of the canal is enlarged which opens into the utricle and has a dilated sac at one end referred to as the osseous ampullae. Within the ampulla is a mound of hair cells and helping cells known as crista ampullaris. These hair cells have many cytoplasmic projections at the apical surface called stereocilia that are embedded in a gelatinous structure known as the cupula. As the pinnacle rotates the duct moves but the endolymph lags behind because of inertia. This deflects the cupula and bends the stereocilia within. The bending of those stereocilia alters an electric powered signal that is transmitted to the central nervous sytem. Within approximately 10 seconds of achieving consistent motion, the endolymph catches up with the motion of the duct and the cupula is now not affected, stopping the sensation of acceleration. The particular gravity of the cupula is similar to that of the endolymph. Consequently, the cupula isn't always displaced through gravity, in contrast to the otolithic membranes of the utricle and saccule. As with macular hair cells, hair cells of the crista ampullaris will depolarise while the stereocilia deflect in the direction of the kinocilium. Deflection inside the opposite route consequences in hyperpolarisation and inhibition. In the horizontal canal, ampullopetal glide is important for hair-cells stimulation, while ampullofugal go with the flow is essential for the anterior and posterior canals.