Chapter 05: Cochlear Physiology

The cochlea is shaped like: (check all that apply)

The scala tympani lies _____ the cochlear duct (scala media) and terminates at the _____ window.

The cochlear duct contains:

The scala tympani and scala vestibuli converge at an opening called the:

_____ separates the cochlear duct from the scala vestibuli.

The basilar membrane separates the cochlear duct from the scala tympani.

The Organ of Corti is powered by the:

Which hair cells are attached to the tectorial membrane?

Hair cells are topped with _____.

Endolymph is similar to:

Endolymph is high in the positive elecrolyte(s):

Perilymph is high in _____ and low in _____.

As Na+ is pumped from the Spiral ligament through the basal cilia and the marginal cells back to the perilymph, _____ is pumped from the perilymph to the endolymph.

The flow of electrolytes from the endolymph to the stria vascularis is what type of flow? (check all that apply)

The scala vestibuli has a potential of 5 mV with respect to the _____.

The scala media (cochlear duct) has a potential of _____ .

Since the Volt is the unit for power, the endocochlear potential serves as the _____ for the transduction process in the cochlea.

Perilymph waves are created at the oval window via ossicular action.

The wave action originates in the _____.

The wave displaces the _____.

This wave action also ‘displaces’ the _____.

The basilar membrane motion’s frequency is _____ to the frequency of the sound.

The specific point at which the basilar wave reaches its maximum peak, or amplitude, is specifically, uniformly based on the _____ of the stimulus.

Lower frequencies create a maximum amplitude near the _____ of the cochlea.

Higher frequencies of stimuli create maximum amplitude in basilar motion near the _____ of the cochlea. (check all that apply)

The wave travels along the basilar membrane until it reaches the point of maximum sensitivity to that specific frequency. At that point, it _____.

Hair cells have a resting Voltage potential of _____ mV.

Hair cells reside in _____ but the stereocilia are bathed in _____.

The potential difference at the apical membrane of the hair cells is, then, _____.

The tectorial membrane and endolymph move along with the basilar membrane.

The hair cell bodies move with the basilar membrane.

The sterocilia are surrounded by mobile/immobile components of the Organ of Corti.

Wave action of the basilar membrane causes _____.

The wave action which bends the cilia toward the _____ row of the cilia _____ the channel (gate) into which K+ ions enter the cells from the endolymph.

What drives the K+ into the cells is the electrical gradient of 120 to 140 mV.

The influx of K+ ions result in a _____ of the hair cell.

When the stereocilia are moved in the opposite direction, the gates then close, thus causing a _____ which results from stopping the flow of K+.

The tips of the stereocilia are linked to each other.

When bending of the tall stereocilum pulls adjacent cilia toward it, the channels for the flow of K+ _____.

When the tallest stereocilium moves back to the resting position, the smaller stereocilia settle back into their resting position, causing the gates (channels) to _____.

By themselves, the stereocilia also amplify sound.

When the motors (myosin motors) adjust the links’ tension, an oscillation of the stereocilia occurs.

The depolarization of IHCs activates afferent nerve fibers.

IHCs act as motor receptors.

The complete cycle of stereociliar motion causes a cycle of:

Since this cycle alternates and results from an electrical potential, it can be measured as an alternating current.

The base of IHCs contain vesicles full of _____.

As IHC depolarization occurs, K+ _____ the cell and _____ enters the cell.

The cation Calcium++ activates Glutamate from the vesicles at the base of the IHC.

Glutamate is a _____.

Glutamate binds the efferent nerve terminals that sends the signal to the brain.

Each IHC is connected to a single dendrite, an afferent nerve fiber ending.

In the hearing organ, _____% of the afferent nerve terminals synapse on IHCs, transmitting sensory signals.

The depolarization of OHCs is identical to that of IHCs.

OHCs are heavily ennervated by afferent nerve fibers.

OHCs _____ the acoustic signal.

The OHC can change it’s length, which is due to its _____.

OHC movement, elongation and contraction, stems from depolarization and polarization.

This action _____ the basilar membrane.

OHCs are _____. (check all that apply)

The volume of OHCs change when they contract laterally and expand in length.

During depolarization, a protein changes its shape in proportion to the OHC\’s voltage changes (CL-), causing the OHC to shorten and thicken. This protein is _____ and is termed a _____.

During hyperpolarization, a protein changes its shape in proportion to the OHC’s voltage changes (CL-), causing the OHC to elongate.