The Vestibular System Flashcards
Know this!!!
What’s in the black box
This is a confusing slide, what are the main takeaways?
Pink: There are 5 sense organs in the Vestibular Apparatus.
The semicircular canals are on 3 orthogonal planes, and there relation to movement of the head: this is purposeful to allow detection of acceleration in all directions.
Green:
Recepto cells (like the cochlea receptors) have cilia that detect movement from the Cupula, but are rooted in base of membrane (like ear).
Cupula connects base membrane to top membrane.
Read all captions!
Explain in greater detail how the semicircular canal works using this slide
Cilia project into the Cupula.
The Cupula is connected at its base to one part of the semi circular canal and top to another.
The Endolymph stays stationary when head moves initially.
Which in turn moves Cupula (cause you are moving) , which moves Cilia.
Why does the Endolymph not move when we initially start moving?
Hint: Endolymph is a fluid surrounding Cupula
Because of inertia. You move, but fluid isn’t attached to you so it doesn’t move with you (at least initially).
At constant velocity (ie no more acceleration), fluid stays put again.
Once you stop fluid then moves again as you deaccelerate.
Fluid only moves when rate of movement is changing, just takes a second for the energy to transfer into movement!
How does dizziness work? Why do you feel dizzy? How do you cure it?
Your Endolymph fluid is continuing to move but you are not moving.
Snap head back in opposite direction of spinning (dizziness that happens by spinning not disease), to counteract the inertia of fluid.
Define what the Visticular Ocular Reflex
The Afferent fibers from vestibular system project into the brain stem, and those neurons go to motor neurons that control the musculature of your eyes.
Very quick with perfect precision unconsciously!
Eyes stay focused even when head it moving!
What is going on when you get a new pair of glasses and you feel dizzy?
Your adapting your vestibulo-ocular reflex. Neruo-plasticity!
We now know what the semicircular canals are used to detect rotation of head. What do the Utricle and Saccule do?
Detect gravitational forces. Using crystals as a weight over gelatinous membrane protecting hair fibers, but still plastic enough to move when crystals move.
Define equilibrium pathway
Note: Cerebellum is like the adaptation cortex of the brain!
Summary slide:
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