English language

How to pronounce utroculus in English?

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hi matrix today's lesson is going to be
on how we hear as well as
our balance and equilibrium
now the purpose of this video is to take
all of these structures that we have
learned about
in the previous two videos and
use them to explain how we actually hear
now at this point you do need to be
familiar with
the structures of the ear the outer ear
the middle and the inner ear
until you are quite familiar with these
names
the explanation will be quite difficult
so spend some time
going through the labels and
familiarizing yourself with
each of their functions okay so
generally you are going to be asked
either in a description or an
explanation an exam
and a test as to how we hear
and you are going to start your
explanation
off with the route in which the sound
waves
take now generally these questions are
sort of
a story-like question they will either
be an essay
or they will be linked to a specific
setting where the examiner has set up
a situation that you then need to apply
it to
so when we explain hearing we need to
mention first of all
the route in which the sound waves take
so you're going to have to mention
something along the lines of the sound
waves are trapped by the pinna
they are then transported down the
auditory canal
and then they make their way to the
tympanic membrane
now it is at this point that you will
need to explain
what amplification is and
a basic definition of amplification is
taking a sound and making it louder and
clearer
now the ear does this in a number of
ways
amplification begins with the tympanic
membrane it's a very large
surface area as you can see it's much
larger than the bone sets it behind
it and what happens is as the sound
waves
hit the tympanic membrane it causes the
tympanic membrane to vibrate
that vibration is transferred onto the
three
ossicle bones the malice the incus
and the stapes now these three
consecutive bones
are all attached to one another
and they bump into one another
and effectively what happens is the
large
surface area of the tympanic membrane
that collects a large amount of sound
waves
that is then passed down to the first
ossicle which is the malice
then the incus and then the stapes and
each successive ossicle bone is smaller
than the previous one
and so what this does is it amplifies
the sound now below the diagram i have
just
included what a marking memo would look
like and please take note of where
the ticks are located you will notice
that
once the sound has been amplified by the
ossicles
you need to mention that it is going to
be transported to the
oval window remember we're not hearing
yet we are only amplifying the sound
now that we have amplified the sound we
now need to look at what goes on inside
of the cochlea which is where hearing
actually takes place
now this is a cross-section through the
cochlea
slightly different to the one that we
looked at in our previous lesson
but next to it i have included the
marking memo for how you would explain
hearing and this marking memo does
include
the beginning stages of what i'd
explained in the previous slide
speaking about things like the pinner
trapping and the sound waves moving into
the inner ear canal
and then that causes the tympanic
membrane to vibrate
um when explaining hearing and then also
explaining amplification
you can put these two explanations in
together
within the same essay
and what you could do is if you look at
the fourth border point here it says the
vibration is transmitted
to the audrey ossicles and the ossicles
amplify
what you can do there is is then you can
go into this
previous explanation about what is
amplification
now we are at the point where our um
sound waves have been amplified they
have been transmitted through the oval
window
and the over window creates waves now it
creates
waves or pressure waves in the endolymph
or the fluid inside the cochlea now if
we look alongside here
there are our three canals the scalar
vestibuli
the media and then tempani you will be
happy to know that you do not need
to know these names and their canals
i've only included them for explanation
purposes
what we do need to know is how
does these pressure waves in the fluid
actually create hearing and so what
happens is
this fluid in the top canal
causes this membrane to vibrate
that membrane causes now the endolymph
inside the most inner canal and that
then causes
the organ of corti it stimulates it
and this entire structure is the organ
of corti
and this is the most important structure
that you need to know in terms of the
organ of corti
you need to know what it does and
effectively it
is converting pressure waves
into electrical impulses
any excess sound waves that aren't
absorbed and interpreted by the organ of
corti
will then move into this lower membrane
and then into the lower
canal where it will then leave through
that perilymph
and exit out through the round window
so if we just take a closer look at what
the organ of corti
looks like continuing on with what our
expected
explanation should look like we
mentioned that
these vibrations stimulate the organ of
corti
and the organ of corti is i will remind
you a set of sensitive hair cells
that are attached to a nerve and sitting
above them
is a tectoral membrane and this membrane
moves backwards and forwards and it
stimulates
the very top tips of the hair cells and
that's how you generate the electrical
impulse
we then mentioned and you must mention
that that impulse is then sent
along to the auditory nerve and finally
to the cerebrum now this specific um
memo was taken from a exam question
where
someone had to explain about being able
to hear
a line raw you just need to fit it into
whatever
the exam question situation is asking
you for
yet again you do not need to know the
name of the tectoral membrane
the baseline membrane you simply need
these structures as
a base point to understand the process
um but in detail they are not needed
now let's move on to how would you
explain the change
of the position of the head
so just to remind you when we speak
about the change in position
uh or the change in posture of the head
in space we are talking about the
utroculus and the sacculus keeping in
mind remember that you have
two one horizontal and one vertical
now this diagram illustrates quite well
exactly what's happening inside those
structures depending on the position
of the head or the posture of the body
so
the gravity or the gravitational pull in
the center
photograph is simply showing a upright
posture
where the otoliths if you remember are
those small little structures
stone-like structures that are attracted
to the gravitational pull
and you will see that right now they are
floating directly above these little
hair cells
and there's no movement in the hair
cells
however if you change your posture
or your head in the space around you
your utriculus and succus will be able
to
sense this and so if we look at this top
diagram over here it says a backward
linear
acceleration that would basically mean
if you are
sitting still but you are
being pushed backwards for example on a
swing
when you do the backwards motion and you
swing backwards
you in terms of your head is still but
your
hair cells are bending forwards and the
otoliths move forward which is how you
sense that your body is moving backwards
it's slightly different to the picture
below it in that
in this instance the head is tilting
forwards
now there is a change in posture and a
change in the head space
and you can see that everything is
tilting forwards
similarly if we look at the other
diagram to the right
up here it says forward linear
acceleration now this is what you would
experience when you're in a car
so you are not moving and your posture
has not changed but you can still feel
the sensation of the car moving
and that is because gravity is pulling
and ex and the acceleration of the car
is pulling on the otoliths and that
causes
the hair cells to bend over slightly
this is also
slightly different to when you tilt your
head back
remember if you're in a car you're
sitting upright and you're not
necessarily moving your head
but the second picture below that is
when you tilt your head backwards
and this is when the otoliths and the
utriculus
or sacculus tilts backwards and now the
head knows it's in a different position
so how would we explain this i've just
attached a little explanation below
from a marking memo and first of all
you always need to acknowledge that
there has been a change in the position
of the head in space this stimulates the
immaculate which is found in the
utriculus and saccules remember the
immaculae is the receptor
this stimulus is then converted into an
impulse
and this impulse is transmitted to the
cerebellum
this is also of course linking to your
previous nervous
system knowledge how does it get to the
cerebellum it moves via the auditory
nerve
and the cerebellum sends impulses to the
muscles to restore posture
this final point is really important
because often this question is a case
study it's an application question and
remember whenever we do these kind of
specific questions where it's asking
what did
the brain do to correct
the action or how did you stop yourself
from falling
etc you do need to circle back
and you need to mention how it was
corrected and in this case
our muscles were coordinated by the
cerebellum
in order to restore our posture and now
finally
we are going to look at how do you
explain a
change in speed and direction and this
now links
to the semicircular canals keeping in
mind
that you have three of them and
remember they're in right angles to one
another so that
you are able to sense a change in
direction in all three dimensions
and keeping in mind that they have their
own sensory receptor
which is found in a swollen region
called the ampulla
and the receptor is called the
crysta so how do we explain this
it is a change in speed and direction of
movement remember you always need to
acknowledge that when you give a
description
it stimulates the crista where are the
crysta they are found in the
semicircular canals
this is converted into an impulse which
is sent to the cerebellum
via the auditory nerve and yet again we
always end off with
um sends an impulse to the muscles to
restore
balance this is slightly different
because we are restoring
balance whereas our previous was
restoring
posture now you do need to provide both
of these explanations
in detail four questions like essays
that perhaps ask someone to explain how
a ballerina maintains their posture and
balance
while spinning on point
you would then need to use both of these
explanations to describe how they
maintain their balance but also their
upright
posture in terms of knowing all of these
structures the most important structures
that you need to be familiar with
um in terms of our semicircular canals
is
the names of them which is the
semicircular canal
and the receptor called the crysta you
don't need to know all of these other
structures
such as the stereocellular the support
cells hair cells
i have included them in my explanations
for order
for you to have a greater and clearer
picture of what you need to know
but it's not necessary um
for you to spend a large amount of time
learning them off by heart
if you do mention any of these
structures in your explanations
then you'll never be penalized for that
and what we are trying to do
is we are trying to teach you a little
bit more than what you need to know
so that when you do answer these
questions you give
a little bit more detail
and a little bit more specific
structural knowledge
so that when you do answer these
questions
you answer them sufficiently without
leaving out any
smaller details now this topic is
quite complex and you may need to
query some of this with your teachers
please do so
as often this particular topic
requires a lot of revision and it's very
technical

hi matrix today's lesson is going to be

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How to pronounce utroculus in English?

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