00:01
The Otolith Organs.
00:03
These also work on the structure of hair cells.
Bending in one direction versus another.
00:10
These structural bent is
all towards the kinocilium.
00:15
This is the tallest
component of the hair cell.
00:19
So if you’re bending in that direction,
you will get a depolarization.
00:23
If you bend in the opposite direction,
you will get a hyperpolarization.
00:28
So how otolith organ works? Are you, are now
putting these various lowcals of hair cells?
All in a little different configuration.
00:40
So that in any movement that you get in the head or
if there is linear acceleration that takes place.
00:46
Some of the hair cells will be bent depolarized,
some will be bent and hyperpolarized.
00:53
It is this coordinated amount of information
that’s sent back to the brain
that helps it understand where it is in space.
01:04
So this otolith arrangement becomes very important.
Which, which way you’re going to bend the hair cells.
01:11
You can orient the hair cells in
multiple directions at the same time.
01:16
And that is what the otolith organs do.
01:19
You have a different orientation of these
hair cells along the different planes.
01:25
That way, you can tell when a little movement
is made in the head in one direction or another
because some of the hair cells are being depolarized
and other ones are being hyperpolarized.
01:36
All depending upon their orientation.
01:40
How do these cells get bent?
There is an interesting process in where there’s
gelatinous material, as well as small stones
that are made up of calcium to have a little bit
of inertia associated with these gelatinous material.
01:58
Therefore, when they’re bent, they will have
a little weight to them and will want to move.
02:03
And as the gelatinous substance
moves, they bend the hair cells.
02:08
You might ask, okay, why do you
need this gelatinous substance?
I mean why stick these hair cells
and something like jello?
The reason is because it allows for
better protection of the hair cells.
02:19
Imagine hair cells are very delicate.
02:22
If you just simply rub stones allover these
hair cells you would break some of them off.
02:27
But having them mixed in these jello-like substance,
you can move the jello round a little bit.
02:34
And with that does is allow for the hair cells
to move but still be in a protected environment.
02:41
So what activates these otolith organ hair cells?
We mentioned movement the number of times
but simply the relation to gravity.
02:51
Are you in a standing position? Or you’re laying supine.
Or maybe you’re sitting in the upright position.
02:58
Or you’re tilting you're head one side or another?
All of those changes are sensed by the otolith organs.
03:06
Because remember that gelatinous substance
has a little weight to it.
03:10
So wherever you are imposition to gravity,
it will poll on that gelatinous substance
and that gelatinous substance will cause some hair cells
to depolarized, another hair cells to hyperpolarized.
03:26
Interesting linear acceleration also does these.
03:30
So if you’re driving in a car in the faster
you go you get these feeling of movement.
03:36
Why because they are, that gelatinous substance
is being moved back as you accelerate forward.
03:43
And that movement of the gelatinous substance
stimulates or depolarizes some of those hair cells.
03:51
Same thing it can happen if ride in an elevator.
03:54
So you could sense linear direction upwards and
downwards just like you can forward and back.