Vestibular (and auditory) Receptors Flashcards
How many types of hair cells exist in the Vestibular Apparatus and what are they activiated by?
Two
Activated by acceleration of the head by a mechanism known as Mechanoelectrical Transduction
Mechanoelectrical Transduction is basically a mechanical deflection of what?
Stereocilia and Kinocilia
Stereocilia and Kinocilia are affiliated with what model?
Gated Spring Model
Stereocilia and Kinocilia are anchored together by _______ that is attached to or near leaky K+ and Ca++ channels NOT Na+
Protein Links
Upon deflection channels in the Stereocilia and Kinocilia are what?
Modified (opened or closed) to increase or decrease the influx of ions
Mechanical deflection by Stereocilia and Kinocilia results in what?
An increase or decrease in the release of neurotranmitters (glutamate?) onto the 1st order neuron
Ther receptor apparatus (ampulla or Macula) are bathed in what?
Endolymph, a fluid high in K+
Inertial movement of the endolymph results in what?
Corresponding movement of the sterocilia in relation to the kinocilia, resulting in an opening or closing of the leaky channels
What are the two types of photoreceptors?
Rods and Cones
Rods are located and most active when?
At times of low light and are located at the periphery of the retina
Cones are located and most active when?
Most active in bright light and are located in the Foveal (central) region of the retina
Rods and Cones, similar to hair cells of the vestibular system are leaky, meaning they result in…
A continueal release of neurotransmitter
When the recetor is activated by light it becomes depolarized/hyperpolarized and results in what?
hyperpolarized resulting in a decrease in neurotransmitter release
The output of the retina is what type of cell?
Ganglion Cell
Prior to the ganglion cell being activatied a great deal of intergration takes place by multiple synapses where?
Through bipolar cells, horizontal cells, and amacrine cells
