L7 : Pharynx; Trachea - Respiration in Organisms, Science, Class 7 Video Lecture

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next part is the pharynx what happens at
pharynx so pharynx is a common passage
for food and air now we take in air
through our nostrils and we take in food
through our mouth now when you take in
food the food goes into the oral cavity
or the bowel cavity from there it goes
into the ferals now when you take in air
it goes through your nostrils then goes
into the nasal cavity and then goes to
the fans so fans is a common passage for
both food and air so they both of them
would pass through the pharynx but after
going to Fallon's they will get
bifurcated into two different routes so
if it is air then it will be sent to
that track lap which is the windpipe so
here you see this bony structure which
you see here this is trachea or windpipe
trachea is also called windpipe and you
see another pipe like structure which
you can see here that is nothing but the
food bank or the eaves or feathers so
once the food or the air enters the
pharynx so the pharynx decides if it is
food it is sent to the food pipe if it
is air then it is sent to the windpipe
now any mistake in this in case by any
chance if a small particle of food
enters into the windpipe that it can
cause it can choke that person and can
even cause death so it can't be that
deadly so therefore the presence of
pharynx is very very important because
it actually decides which has to go
which way so let's say you have come out
of your house now once you reach a
junction from where if you take right
you will reach your school and if you
take left you reach the shopping complex
so that is the point where you have to
decide which way you want to go whether
you want to go right or never
so similarly here also once the food or
air reaches pharynx
to decide if it is food it has to be
sent to food buy if it is air it has to
be sent to windpipe or trachea so the
food goes to the esophagus ESO Figgis is
nothing but the food pipe food pipe is
also called
esophagus and the air goes to track here
and track here is nothing but the
windpipe so in this lesson we will be
continuously talking about track here so
track your lines in front of the ESO FEA
so if you see they both lie just one
behind another so windpipe is on the
front and the food pipe is present at
the back of the windpipe another
important structure which is present
here is called the epiglottis you know
what is epiglottis as I said it is very
important that food goes to food pipe
and food doesn't enter into the windpipe
now how do we prevent it that food can
not enter into trakula so this
prevention is done by this structure
called epiglottis so epiglottis prevents
food from entering into the trachea or
the windpipe so it is a small party
latching his flap of skin so as you can
see here so this is epiglottis you see a
flap of skin here brown colored
structure that is nothing but epiglottis
so it is like a door and the door
remains closed whenever it is food but
whenever it is air it opens up and it
allows it to pass to the windpipe so it
is a party to make this made up of
cartilage and so small flap of skin it
prevents food from entering into the
respiratory tract respiratory tract is
nothing but the windpipe or the trachea
so presence of epiglottis press does a
very useful job because this is a very
critical thing so epiglottis helps so
the next part is again a crucial part
that is tract here which is also called
as the windpipe
so this is the place or this is the
tube-like structure which provides a
passage for air so air passes from
pharynx into the spine
so from pharynx it gets into the track
here now what is the track key or how
does the track here look like and what
is it made above so if you look at the
structure of track we are using you you
will actually be able to see some
ring-like structures so these rings are
made up of cartilage and the presence of
these party lagina's rings prevents the
collapsing of the track yam even if
there is no air so you know it is it is
kind of a tube so inside the tube if
even if you don't have air it shouldn't
like deflate so it should remain as it
is and for that purpose we have these
rings which are made up of cartilage so
that the track here doesn't collapse
whether irrespective of whether air is
there inside or not so that's one thing
about the structure of track here the
presence of cartilaginous ring so here
this windpipe it extends up to the mid
thoracic cavity so we are just talking
about its location now now what do we
mean by meet thoracic cavity what is
thoracic cavity for that matter now if
you look at our bonding you will
actually see that it is divided into
three different sections so basically
this portion is the head correct and
this portion between the head and the
abdomen this portion is known as the
thorax therefore this entire eight part
is termed as that this entire cavity and
all the organs present in this space
they are safe to cover the thoracic
cavity so thoracic cavity it is the
division of an animal's body which is
between the head and the abdomen so this
is head and this is abdomen
so between head and abdomen
is the thoracic cavity so this track
here
stands up to mid thoracic cavity you see
this presence of this diagram there is a
muscular structure here and this
diaphragm it denotes the end of thoracic
cavity so wherever you have this
muscular structure you see the structure
so this egg denotes the end of the
thoracic cavity so that here the
thoracic cavity ends so mid mid of the
thoracic cavity is where till which the
rakia
extend so the trachea extends up to the
mid of thoracic cavity so that is the
location of trachea C shaped rings of
cartilage presents as I said and these
cartilage rings what do they do they
provide support and rigidity therefore
the trachea never collapse even if there
is no air inside the trachea it will not
collapse also internally the trachea is
lined by celia and mucus now whenever I
talk about C here and Luca see here
being here the tiny hairlike structure
they will always block the dust
particles microorganisms germs and other
foreign matter from getting inside so
you see at every step of our respiratory
system everywhere we have some filter
mechanism so that we can block the entry
of unwanted particles for example in the
nostrils nasal cavity there also we had
Celia we had mucus we had tiny hair
similarly here also using here in case
of trachea here also you have Celia you
have mucus so everywhere this filters
are present this protection are present
so that unwanted particles do not enter
inside our lungs they should not reach
our lungs and cause any kind of
infection so Rams from throat till the
thoracic cavity so as it as I said so
that that's the location of the track
lighting which we have already this
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