helicotrema การใช้

• The wave in the perilymph moves away from the footplate and towards the helicotrema.
• This area is called the helicotrema.
• He used glass slides, razor blades, and an elastic membrane to represent the helicotrema.
• Higher frequencies do not propagate to the " helicotrema ", due to the stiffness-mediated tonotopy.
• At the apical end of the cochlea, at an opening known as the helicotrema, the scala vestibuli merges with the scala tympani.
• Near the summit of the cochlea the lamina ends in a hook-shaped process, the hamulus laminae spiralis; this assists in forming the boundary of a small opening, the helicotrema, through which the two scalae communicate with each other.
• For " very low frequencies " ( below 20 Hz ), the waves propagate along the complete route of the cochlea  differentially up " vestibular duct " and " tympanic duct " all the way to the " helicotrema ".
• This continuation at the helicotrema allows fluid being pushed into the vestibular duct by the oval window to move back out via movement in the tympanic duct and deflection of the round window; since the fluid is nearly incompressible and the bony walls are rigid, it is essential for the conserved fluid volume to exit somewhere.
• The farther a wave travels towards the cochlea's apex ( the " helicotrema " ), the less stiff the basilar membrane is; thus lower frequencies travel down the tube, and the less-stiff membrane is moved most easily by them where the reduced stiffness allows : that is, as the basilar membrane gets less and less stiff, waves slow down and it responds better to lower frequencies.