00:01
So starting with the larynx,
which is the most
superior portion
of the lower respiratory tract
just after the pharynx.
00:09
They have three main functions.
00:11
The first is to
provide a patent airway
or basically an open and
clear passage for air.
00:20
The larynx is also going
to route air and food
into their proper channels.
00:26
This happens by way
of a structure known
as the epiglottis.
00:30
The epiglottis is going
to be open during speech.
00:34
But when you swallow your
food the epiglottis closes
so that food does not get
into the respiratory tract.
00:42
So what happens
when you talk and
eat at the same time
sometimes our food goes
down the wrong pipe.
00:48
This is what happens
when epiglottis is open
while you are swallowing.
00:55
The third function of the larynx
is going to be voice production
and this takes place using
the house vocal folds.
01:05
So if we look a little bit
closer at voice production,
we find that speech is
the intermittent release
of expired air
during the opening
and closing of a structure
known as the glottis.
01:18
The glottis includes
the vocal folds
as well as the space in
between these two folds.
01:25
We also refer to the vocal
folds as the vocal cords.
01:32
When it comes to pitch
or the pitch of your voice,
soprano or base,
your vocal cords are attached to
laryngeal muscles.
01:41
These laryngeal muscles
are going to create a tension
that is like the tuning
of a string instrument.
01:48
The pitch is going to be
determined by the length
and the tension of
these vocal cords
as they are being pulled
by these laryngeal muscles.
02:00
While pitch is
determined by tension
loudness of sound
is going to be determined
by the force of air
that goes through the glottis.
02:11
So along with the larynx,
we also have chambers
of the pharynx
the oral nate, oral
cavity, the nasal cavity
and the sinus cavities
that are all going to
take part in amplifying
enhancing sound quality.
02:28
We shape our sound
into language or speech
by the muscles of the pharynx
as well as the tongue,
the soft palate and the lips.
02:39
So speech is like
a coordinated dance
between all of these structures.
02:46
The larynx can also serve
a sphincters function.
02:51
In this case the vocal
folds may act as a sphincter
in order to prevent air passage.
02:58
A good example of this
is the valsalva maneuver.
03:01
During this, the glottis
is going to close
in order to prevent
air from exhaling
or being released
from the air passage.
03:12
At the same time the abdominal
muscles are going to contract
and these two processes
cause the intra-abdominal
pressure to increase.
03:24
Together this will help
do things like empty the rectum
or in the case of heavy lifting
like in weightlifting,
stabilizing the trunk.
03:33
So if you've ever
noticed in weightlifting
when a person lifts weights,
a lot of times, it looks like
they're holding their breath
and they actually sometimes
have to be reminded to breathe
so they don't pass out.
03:44
This is due to the
valsalva maneuver.