Respiratory System | Structure and Function
Summary
TLDRThe video introduces the basics of the respiratory system, starting with a practice of breathing, followed by an explanation of how it works. It covers key components like the nasal cavity, nasal concha, and olfactory bulb, explaining how air is warmed, humidified, and filtered. The video discusses sinuses, the function of the uvula, and how the epiglottis prevents food from entering the trachea. The anatomy of the trachea, lungs, and diaphragm is explained, highlighting the gas exchange in the alveoli and the importance of the rib cage and pleural membrane in protecting the lungs.
Takeaways
- đŹïž The respiratory system allows us to breathe in air through the nasal cavity, which is then warmed, humidified, and filtered by nasal concha.
- đ The olfactory bulb in the nasal cavity helps detect smells by interacting with particles in the air and sending signals to the brain.
- đ· Sinuses, which are mucus-lined cavities, produce mucus to trap pathogens and lubricate the nasal cavity.
- đ The oral cavity is primarily occupied by the tongue, which contains taste buds for detecting five main tastes: sweet, salty, sour, bitter, and umami.
- đ The Eustachian tube connects the nasal cavity to the inner ear, helping equalize air pressure during changes in altitude, such as flying or driving in mountains.
- đ The uvula in the back of the throat prevents food from entering the nasal cavity, though it isnât perfect, as food can still escape into the nose when laughing.
- đ« The trachea is kept open by cartilage rings to ensure airflow, while the epiglottis prevents food from entering the trachea during swallowing.
- đ€ The larynx, or voice box, contains vocal cords that produce sound when air passes through them. The thyroid cartilage, also known as the Adam's apple, protects the larynx.
- đ Bronchi branch into smaller bronchioles, which end in alveoli. These alveoli are where gas exchange (oxygen and carbon dioxide) takes place with the bloodstream.
- đ« The diaphragm contracts to expand the pleural cavity, causing air to rush into the lungs. It plays a key role in breathing, with the ribcage protecting the lungs and other thoracic organs.
Q & A
What is the function of the nasal concha in the respiratory system?
-The nasal concha slows the air down as it enters the nasal cavity, helping to warm and humidify it. This also aids in trapping pathogens and improving the sense of smell.
How does the olfactory bulb help us detect smells?
-The olfactory bulb contains sensory neurons that detect smell molecules in the air. These molecules interact with receptors in the nasal cavity, sending signals to the brain to identify the smells.
What is the role of sinuses in the respiratory system?
-Sinuses are mucus-lined cavities that produce mucus, which helps trap pathogens, lubricates the nasal cavity, and drains into the nasal cavity to maintain moisture.
What is the purpose of the eustachian tube?
-The eustachian tube connects the nasal cavity to the inner ear and helps equalize pressure between the inner ear and the outside atmosphere, especially during changes in elevation.
How does the uvula prevent food from entering the nasal cavity?
-The uvula is a flap of tissue that prevents food and liquids from entering the nasal cavity when swallowing. However, it is not foolproof, which is why food can sometimes come out through the nose when laughing.
What is the function of the epiglottis in the respiratory system?
-The epiglottis is a flap of tissue that covers the trachea during swallowing, preventing food and liquids from entering the lungs, which would cause choking or coughing.
What is the role of the larynx and how does it produce sound?
-The larynx, or voice box, contains the vocal cords. Air pushed through the vocal cords causes them to vibrate, producing sound. The pitch of the voice is determined by the length and tension of the vocal cords.
Why is the trachea held open by cartilage rings?
-The trachea is held open by cartilage rings to ensure it remains open at all times for air to flow in and out of the lungs. Without the rings, the trachea could collapse, blocking airflow.
What is the function of alveoli in the lungs?
-Alveoli are small sac-like structures at the end of bronchioles where gas exchange occurs. Oxygen from the air passes into the bloodstream, and carbon dioxide is expelled from the blood to be exhaled.
How does the diaphragm help in breathing?
-The diaphragm contracts downward to expand the pleural cavity, creating a pressure difference that causes air to rush into the lungs, enabling breathing.
Outlines
đ« Introduction to the Respiratory System and Nasal Cavity
In the first part of the video, we start by practicing how to use the respiratory system before moving on to understanding its workings. The focus then shifts to the nasal cavity, explaining how air enters through the nostrils and is slowed down by three shell-like ridges called nasal conchae. These structures help warm and humidify the air, enhance our sense of smell, and trap pathogens. The olfactory bulb plays a key role in detecting smells by capturing air particles that interact with receptors. The discussion covers how nasal sinuses produce mucus and trap pathogens, protecting the respiratory system.
đ Oral Cavity, Eustachian Tube, and Pharynx
This section introduces the oral cavity, where the tongue fills most of the space and is responsible for our sense of taste. It explains the Eustachian tube's role in balancing air pressure between the inner ear and the atmosphere, which is why our ears pop during altitude changes. Additionally, the pharynx, or the back of the throat, is discussed along with the uvula, a flap that prevents food from entering the nasal cavity, though itâs not foolproof, as demonstrated when food or drinks can sometimes come out of the nose.
đ§ Epiglottis, Larynx, and Vocal Cords
This part covers the distinction between the esophagus, where food travels, and the trachea, where air flows. The epiglottis ensures that food doesnât enter the trachea when swallowing, while the larynx, or voice box, produces sound. The vocal cords vibrate as air passes through, with pitch depending on the size and tension of the cords. Laryngitis, an inflammation of the vocal cords, affects speech. The section also discusses the thyroid cartilage (Adam's apple), which protects the larynx, and the importance of cartilage rings in keeping the trachea open for constant airflow.
đŹïž The Bronchi, Bronchioles, and Alveoli
Here, the video explains how the trachea branches into two bronchi, each entering a lung and further dividing into bronchioles. These bronchioles end in alveoli, small sacs where gas exchange occursâoxygen enters the bloodstream, and carbon dioxide exits to be expelled from the body. This segment emphasizes the critical role of alveoli in facilitating the respiratory system's primary function of oxygenating the blood and removing carbon dioxide.
đ« Lung Structure, Pleural Membrane, and Diaphragm
The lungs are discussed next, highlighting that the left lung has two lobes while the right lung has three. Each lung is surrounded by a pleural membrane, and the pressure inside the pleural cavity is slightly lower than in the lungs, which keeps them inflated. The diaphragm plays a crucial role in breathing by contracting to expand the pleural cavity, allowing air to rush into the lungs. The ribcage protects both the lungs and heart, ensuring that these vital organs are shielded from damage.
đ Recap and Summary of Respiratory System Functions
This section recaps the key points about the respiratory system, from the nasal and oral cavities to the lungs. It highlights the importance of the nasal conchae in filtering and humidifying air, the olfactory bulb in detecting smells, the roles of the uvula and epiglottis in preventing food from entering the wrong passages, and the crucial function of the alveoli in gas exchange. The video concludes with a reminder of the diaphragmâs role in breathing and the ribcage's function in protecting the thoracic organs.
Mindmap
Keywords
đĄNasal cavity
đĄNasal concha
đĄOlfactory bulb
đĄSinuses
đĄPharynx
đĄEpiglottis
đĄTrachea
đĄAlveoli
đĄDiaphragm
đĄPleural membrane
Highlights
Introduction to the respiratory system with a focus on how we use it by breathing in and out.
Explanation of the nasal cavity's structure and function, including the role of the nasal concha in slowing down air for better humidification and pathogen trapping.
Detailed discussion of the olfactory bulb and how sensory neurons help us detect smells by interacting with particles in the air.
Description of the sinus cavities and their role in mucus production, which helps lubricate the nasal cavity and trap pathogens.
Explanation of the oral cavity, highlighting the size and function of the tongue, and the role of taste buds in detecting five distinct tastes.
Overview of the eustachian tube, which connects the nasal cavity to the inner ear and helps equalize pressure during changes in elevation.
Introduction to the pharynx, the back of the throat, and the uvula, which helps prevent food from entering the nasal cavity.
Description of the epiglottis, a flap of tissue that prevents food from entering the trachea when swallowing.
Explanation of the trachea's structure and function, including its division into two bronchi that lead to the lungs.
Introduction to the alveoli, small sacs at the end of the bronchioles where gas exchange between air and blood occurs.
Description of the differences between the right and left lungs, with the right lung having three lobes and the left lung having two lobes.
Explanation of the pleural membrane and the importance of keeping a lower pressure in the pleural cavity to prevent lung collapse.
Overview of the diaphragm's role in breathing by contracting to expand the pleural cavity, allowing air to flow into the lungs.
Introduction to the rib cage's role in protecting the lungs and other thoracic organs.
Recap of the entire respiratory system, including a step-by-step review of the structures and their functions in the breathing process.
Transcripts
first part of the video we're going to
practice using the respiratory system
then we'll learn how it all works so
take a deep breath in
and then breathe out now that we've
mastered using the respiratory system
we're going to learn how it works
let's jump to the white board we're
going to start with the nasal cavity now
you're probably already familiar with
the nasal cavity it's the
open area between your nostril and the
back of your throat but you probably
haven't explored too far
back there before i was a picking your
nose joke now you'll notice in the nasal
cavity that there are these three ridges
called the nasal
concha it's the same root as conch like
a conch shell
and so these are three shell-like ridges
in the nose
and the purpose of these is to slow the
air down which will warm it
help it stay humidified we also smell in
the nose so by keeping the air is kind
of swirling around in there a little bit
longer it helps with our sense of smell
and it can help trap pathogens in there
think about if the air just went
straight back down the throat right away
then it would be easier for pathogens to
make it through but if the air swirls a
little bit those pathogens can get
caught in our mucus and our nose hairs
and things like that so the nasal concha
are there to slow the air that we
breathe in
to help trap pathogens help us smell
better and warm and humidify the air
that we breathe now at the top of this
in yellow drawn here is the olfactory
bulb olfactory just means smell i think
about like
you're driving down the highway and you
smell oh that's the fact there's like an
old factory nearby
and it smells really bad like they're
making dog food or something and it's a
smelly old factory olfactory sense
the olfactory bulb has sensory neurons
that hang down in here
and whenever we smell something it's
actually the molecules
of that thing that are in the air are
going to interact with those little
receptors
that hang down from our olfactory bulb
and sends
signals then to our brain so this
olfactory nerve right here
connects back to our brain so that we
can detect what we're smelling
so next time you smell something that
doesn't smell very good remember there's
actual particles of that thing
making it into your nose all right let's
move on
drawn here now are a couple of our nasal
sinuses
our sinuses are these mucus-lined
cavities whose job is to make
mucus and of course when they get
infected then we have a sinus infection
we've got kind of four sets of those
i've got two drawn here
the frontal and the sphenoid the frontal
sinus is right in here
the sphenoid sinus is kind of back
behind the nose we also have the
maxillary sinuses which are in our
cheekbones
and the ethmoid sinuses which are
between our eyes but just know for now
that the sinus cavities are mucus-lined
cavities
that drain down into the nasal cavity
which is where we produce our mucus or
snot
mucus of course is really important
helps lubricate your nasal cavity and
also helps keep pathogens in it traps
those pathogens
and if stuff gets in there that
shouldn't be there that's why we have
runny nose to try to get rid of those
pathogens that have made it into
our nasal cavity up next we have the
oral cavity
the oral cavity of course is our mouth
now
in my diagram here it looks like we have
a big open oral cavity but most of that
oral cavity is actually taken up
by our tongue think of your tongue as
this like little bitty piece that kind
of like sticks out of your mouth
but your tongue is giant and it fills up
most of your mouth the tongue of course
has taste buds which are connected to
sensory neurons which sends signals up
to the brain for
tasting our five things that we can
taste sweet salty bitter
sour and umami anything else that we
taste like flavors that's really our
sense of smell
if it's not one of those five we didn't
taste it we smelled it up next we have
this little
opening it's the opening to a tube
called the eustachian tube and it's
found
sort of in the back of our nasal cavity
right there and that's going to connect
our nasal cavity
to our inner ear think of a time where
you've been changing elevation like
going on a flight in a plane or driving
up into the mountains
and your ears start to pop well that's
because the inside of your ear not the
part that you can get to like this
but the part that's on the inside of
your eardrum if that inner ear part has
a different
pressure than the air pressure on the
outside of your ear then it
it starts to feel weird it can hurt and
then whenever your ears pop
or equalize the pressure that's because
air can float in or out of the
eustachian tube
and that's why it helps to like chew gum
or to swallow or to yawn
those things will help open up the
eustachian tube so air can pass in or
out
to equalize the pressure between the
atmosphere around us
and our inner ear now the back of the
throat we have a special name for which
we call
the pharynx the pharynx it's not a
special structure
it's just a name for the back of the
throat so pharynx is the back of the
throat
and we have this thing called the uvula
now if you've ever seen a cartoon where
the character opens their mouth and in
the very back of the throat there's like
this dangly red thing right there
i always used to think that was the
tonsils but it's not the tonsils
it's the uvula the purpose of the uvula
which is this flap of skin that hangs
down in the back of the throat
is to prevent food and other things that
we eat or drink
from making it into our nasal cavity now
it's not perfect if you've ever had milk
come out your nose because you were
laughing while you were drinking milk
then that's because your oral cavity and
your nasal cavity are connected
and your uvula is not perfect and
whenever you were laughing some of that
food made it from
the back of the throat here and the oral
cavity up into
the nasal cavity and that's never a
pleasant feeling so the uvula prevents
food from making it into your nasal
cavity up next we have two tubes that
the throat divides into
one is going to be the esophagus and
that's where you want food to go
the other tube is the trachea and the
trachea we want to stay
open because we breathe in and out and
that air goes into the trachea and we
we're never not breathing right
generally so it's helpful if we keep the
trachea just
open all the time the one time when we
don't want the trachea open
is whenever we're swallowing food or
drink so to help prevent
food or liquid from getting down into
the trachea and therefore down into the
lungs
which is what's happening whenever you
take a drink of something and it goes
down the wrong way and you start
coughing
that's you getting that liquid or that
food out of your
lungs well we've got a special structure
to prevent this from happening and
that's called
the epiglottis the glottis is sort of a
term for the top of the voice box right
here so epiglottis means above that and
whenever you swallow
this flap of tissue right here gets
pulled on by a tendon right here and
it's going to bend that down to
cover up the space right here so the
moment that you're swallowing food food
all goes down into the esophagus and
none of it goes down
into the trachea which would cause you
to cough so two things that keep the
food where it needs to be we've got the
uvula which prevents food from going up
into the nasal cavity and we have the
epiglottis which prevents food from
going down into the trachea and
therefore into the lungs
now at the superior part or top of the
trachea we have something called the
larynx
the larynx is another name for your
voice box and right here
drawn are the vocal cords whenever you
speak
air is pushed up through the trachea out
of your lungs and it causes the vocal
cords to vibrate the wider or longer
your vocal cords the deeper your voice
will be
and the smaller your vocal cords the
higher it will be and of course you can
change the pitch of your voice because
you can
change the vibration frequency of your
vocal cords but only to an extent so we
all have a limited
vocal range and if you have inflammation
of this area where it swells up and your
vocal cords aren't able to vibrate then
you've got
laryngitis laryngitis is inflammation
that's the itis part
of the larynx laryngitis now we need to
protect our larynx so we have a special
piece of cartilage called the thyroid
cartilage
that sits in front of our larynx this is
also known as that adam's apple
and men and women both have it it tends
to be more pronounced in men so people
think
that just men have an atom's apple but
really men and women both have it it has
nothing to do with the thyroid gland and
the endocrine system as far as what it
does or what it is
the only similarity there is where it's
located which is why they share the name
so thyroid cartilage protects the larynx
next we have the rest of the trachea
you'll notice the trachea is covered in
these cartilage rings i use light blue
in the diagram here for cartilage
they're covered in these cartilage rings
and the purpose of that is to hold
open the trachea like i said we're
always breathing we want the trachea to
never be obstructed because then we
couldn't get oxygen into our lungs that
would be bad
so these cartilage rings hold open the
trachea so there's always
air flow moving in or out of our lungs
contrast that with the esophagus which
stays closed most of the time if we're
not swallowing food or drinking water
and at the bottom
of the trachea it splits into two what
we call bronchi or bronchus for singular
but two of them so there's two bronchi
the bronchi enter each lung and from
there they're going to branch out into
smaller divisions called bronchioles so
trachea there's just one
they're split into two bronchi and each
bronchus
splits into many bronchioles that
changing of the ending to
oles that just means they're smaller
like arterioles or small arteries or
venules are small veins now in the lung
at the end of
each bronchiole is a little sort of
cloud-shaped sac
called alveoli contrary to popular
belief alveoli are not my favorite type
of pasta that would be penne just
kidding all pasta is
delicious but the alveoli are where the
air ends up going so that it can
transfer
oxygen and carbon dioxide back and forth
between
the air that we breathe and the blood
vessels that enter our lungs
so each of these little alveoli that are
at the end of the bronchioles
those are wrapped in little capillaries
little tiny blood vessels that connect
to our bloodstream
so they can exchange the oxygen and the
air that we breathe
into the bloodstream and then take out
the carbon dioxide that we don't need
anymore
out of the bloodstream so that we can
breathe it out so the alveoli is where
gas
exchange occurs that's super important
that's the whole point of all this right
to get oxygen into our bloodstream
that happens in the alveoli and of
course we have two lungs now while the
second lung is being drawn
notice something that this left lung
this is the left side by the way it's
the right side from your perspective but
if this person's facing you it's their
left so the left lung has two lobes so
lower lobe
upper lobe our right lung however has
three lobes so we've got a lower
a middle and an upper lobe so right lung
three lobes
left lung two lobes now around each lung
is a pleural membrane the lungs are in
the pleural cavities and the pleural
cavities are surrounded by this membrane
it's really important actually the
pressure in the lungs right here like in
the bronchi and the bronchioles
is actually a little bit higher than the
pressure in the pleural cavity
that's surrounded by the pleural
membrane think about it like a balloon
your lungs are like a balloon
if the balloon has the same pressure as
the air around it it's actually
deflated we don't want our lungs to
deflate we call that a collapsed lung it
can happen whenever
the lung itself gets damaged or if the
pleural membrane gets punctured
so we have to keep this space right in
there between the lung
and the pleural membrane we actually
have to keep that at a negative relative
pressure it's got to be at a lower
pressure
than the lung itself so the lung stays
inflated like a balloon the pressure in
the balloon has to be higher than the
pressure around it
for it to stay inflated so just remember
in the pleural cavities
the pressure is a little bit lower than
in the lungs below the lungs we have
the diaphragm you may have had a music
teacher say you know to sing from your
diaphragm but you also have to breathe
from your diaphragm
your lungs actually you don't breathe
with your lungs you don't send signals
to your lungs to breathe
you send signals to your diaphragm what
the diaphragm does is it contracts
downward which expands the size of your
pleural cavity that's going to cause
air to rush into the lungs because of
that pressure difference
sort of like sucking liquid through a
straw so you can track the diaphragm
down
that's going to cause air to rush into
the lungs and your lungs then expand
but again you're not controlling the
lungs directly you're controlling the
diaphragm so the diaphragm
helps you breathe by expanding the
pleural cavity
finally of course all of the thoracic
cavity is surrounded and protected by
our rib cage and the purpose of those is
to protect
our lungs and our heart and our other
thoracic organs from being damaged
all right let's do a quick recap we have
the nasal cavity which is where we
breathe air
into our nose we have the nasal concha
which are there to
swirl the air and warm it humidify it
trap pathogens
as well as keep the air there a little
bit longer so we can smell it better we
have the oral cavity which is our mouth
and most of that's filled with our
tongue
we have the olfactory bulb which is for
detecting smell molecules will connect
to those receptors
and that'll cause signals to be sent
back to our brain so we can process
those
things that we smell we have the sinus
cavities which are lined with mucosa or
membranes that produce mucus to help
lubricate our nose and help flush out
pathogens and things like that we have
the eustachian tube which connects to
our inner ear and that's going to help
equalize the pressure between our inner
ear
and the air around us we have the uvula
which is going to prevent food from
making it from our oral cavity
up to our nasal cavity which is not good
the pharynx is a name for the back of
the throat
the epiglottis is a flap of tissue that
whenever we swallow it's going to close
off the trachea to prevent food and
water from making it down into our lungs
we have the esophagus right there
and then the trachea at the top of the
trachea is the larynx
which is going to be where our vocal
cords are the thyroid cartilage protects
the larynx
that's the adam's apple the trachea is
held open by these cartilage rings
and then the trachea branches into two
bronchi each bronchus branches into
bronchioles and then finally down into
alveoli
alveoli is where gas exchange occurs
oxygen will go from the alveoli into the
blood and carbon dioxide will go from
the blood
into the alveoli so we can breathe it
out the lungs of course are surrounded
by the pleural membrane
and the space inside the pleural
membrane is kept at a lower pressure
so their lungs stay inflated we've got
the diaphragm which we contract in order
to breathe
and the ribcage of course protects all
of the thoracic organs that we've been
talking about all right here's a blank
diagram take a moment see if you can
identify all of the structures in this
diagram
as well as what they do here we have the
nasal cavity which we bring air into
we've got the nasal concha which are
going to swirl the air we've got the
oral cavity which is our mouth
we've got the olfactory bulb which is
for sensing smell we have the sinus
cavities
we have the eustachian tube which
connects to our inner ear we have the
uvulo which prevents food from getting
into the nasal cavity
we've got the pharynx which is the back
of the throat we have the epiglottis
which prevents food from making it down
into the trachea
we've got the larynx which is where our
vocal cords are we've got the thyroid
cartilage which protects our larynx our
vocal box we have the esophagus which is
where food and
drink go down we have the trachea which
is where air goes down into that trachea
branches into the two bronchi which
branch into bronchioles
which end in alveoli where gas exchange
occurs with the bloodstream
we have the lungs which are covered in
the pleural membrane
the left lung has two lobes the right
lung has three lobes the diaphragm which
will contract to help us breathe and
finally the rib cage which protects all
of this
take a moment and breathe okay we're
gonna use our respiratory system breathe
in
breathe out
you think that's funny
good job wait where'd the laundry go
where did laundry go
there she is right bye bye
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