About the physiology of hearing

Abstract

Jan Myjkowski

The membrana basilaris plays an important role in the theory of traveling wave. It originates from the ectoblast of the connective tissue, and is bereft of both afferent or efferent innervation. Vibrations of the membrana basilaris formed into a transverse wave occur together with the organ of Corti and a band of connective tissue on the inferior membrane surface. Vibrations take place in a fluid which has suppressive properties. The length and the mass of the membrana basilaris in mammals and birds are very different and there is no relationship between the membrane basilaris length and the length of the sound wave, especially in the range of low frequencies. Small sound intensities, supraliminal, have amplitudes within the limits of a few picometers upon the entrance into the auditory meatus. This amplitude disappears in cochlear fluids and cannot reach the receptor through cochlear fluids. It cannot be intensified by OHC contractions, since there is no depolarization of the external acoustic cell. Short sounds, whose duration time is equal to tenth parts of milliseconds, are perceived by the receptor and recognized is the frequency of those waves, although they do not generate any resonance with the membrana basilaris. Attention was paid to molecular, intracellular transformations responsible for the transfer of information and intracellular amplification. An important role in those processes is played by ion channels of sodium, potassium, calcium and chlorine in the lateral and inferior wall of the acoustic cell. They are responsible for the polarization and depolarization of a cell. Underlined is the role of calcium in the signal transmission and its amplification in an acoustic cell.

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