THE RESPIRATORY SYSTEM | Introduction to structures and fucntions

Summary

In this educational video, Miss Angler introduces the respiratory system, detailing its structures and functions. She explains the benefits of nasal breathing, including the role of nose hairs and mucus in filtering air. The script delves into the anatomy of the respiratory system, from the trachea to the bronchi and bronchioles, culminating in the alveoli where gaseous exchange occurs. Miss Angler emphasizes the importance of the alveoli's large surface area, thin walls, and moisture layer for efficient gas exchange, and concludes with a terminology recap to reinforce learning.

Takeaways

• 👃 Breathing through the nose is preferable due to its role in filtering, warming, and humidifying the air before it enters the respiratory system.
• 🕊 Nasal hairs and mucus in the nose serve as the first line of defense, trapping foreign particles like dust, bacteria, and viruses.
• 🌡 The nose warms the inhaled air to maintain the body’s optimal temperature of around 37 degrees Celsius.
• 🗣 The larynx, also known as the voice box, is where vocal cords are located and is crucial for speech, while the pharynx is involved in swallowing.
• 🌀 The trachea, or windpipe, is supported by cartilaginous rings that prevent it from collapsing, ensuring a clear passage for air.
• 💨 The bronchi are the main branches of the trachea that lead to the lungs, lined with ciliated cells to further filter out particles.
• 🌿 Bronchioles are smaller branches of the bronchi that continue to narrow down, eventually leading to the alveoli.
• 🌫 Alveoli are tiny air sacs at the end of the bronchioles where gaseous exchange occurs, featuring a large surface area and thin walls for efficient oxygen and carbon dioxide transfer.
• 💧 Alveoli are surrounded by a capillary network and a moisture layer, which facilitates the diffusion of gases during respiration.
• 🏋️‍♂️ The diaphragm and intercostal muscles are essential for the breathing process, expanding and contracting the thoracic cavity to draw in and expel air.
• 🛡️ The pleura membrane and pleural fluid protect the lungs by reducing friction between the lung surfaces and the thoracic cavity.

Q & A

Why is it better to breathe through the nose rather than the mouth?

Breathing through the nose is better because the nasal cavity warms, filters, and humidifies the air, preventing infections and reducing the load on the body's immune system.

What is the function of nose hairs in the respiratory system?

Nose hairs act as a filter to trap foreign particles, preventing them from entering deeper into the nasal passage and potentially causing infection.

What is mucus and why is it important in the respiratory system?

Mucus is a secretion that contains water and proteins, serving to trap dust, viral, bacterial particles, and fungal spores, thus protecting the body from infections.

Why is the trachea lined with mucus?

The trachea is lined with mucus to trap foreign particles and provide lubrication, facilitating the movement of particles and preventing irritation.

What are the bronchi and what is their role in the respiratory system?

The bronchi are the two main branches of the trachea that lead to the lungs. They are lined with ciliated cells to trap dust, mucus, and particles, preventing them from entering the lungs.

How many lobes do the human lungs typically have and why is there a difference?

Typically, the human lungs have five lobes, with three in the right lung and two in the left lung. The left lung is slightly smaller to accommodate the heart.

What is the diaphragm and how does it contribute to the breathing process?

The diaphragm is a muscle that moves up and down, allowing for the expansion and contraction of the thoracic cavity, which in turn facilitates the inhalation and exhalation of air.

What is the pleura and what is its function?

The pleura is a thin membrane that surrounds the lungs and secretes a fluid to reduce friction between the lungs and the chest wall, protecting the lung tissue.

What are the alveoli and why are they important for gaseous exchange?

Alveoli are tiny air sacs at the end of the bronchioles where gaseous exchange occurs. They are crucial because of their large surface area, thin walls, and moisture layer, which facilitate the efficient diffusion of oxygen and carbon dioxide.

What are the requirements for efficient gaseous exchange in the alveoli?

The requirements for efficient gaseous exchange in the alveoli include a large surface area, a thin surface to allow rapid diffusion, a moisture layer for gas dissolution, a rich capillary network for gas transport, adequate ventilation, and protection from the respiratory system structures.

What is the significance of the intercostal muscles in the respiratory process?

The intercostal muscles, along with the diaphragm, are essential for breathing as they initiate the expansion of the thoracic cavity, allowing air to be drawn in during inhalation.

Outlines

00:00

👃 Introduction to the Respiratory System

Miss Angler begins the video by welcoming viewers to her biology class, where she introduces the topic of the respiratory system. She outlines the plan to cover various structures and their functions, with an emphasis on how they facilitate gas exchange. The video will also include annotations of these structures. Miss Angler mentions that more detailed videos on gaseous exchange will be available and encourages viewers to subscribe for more life sciences content. She starts the exploration of the respiratory system with the nose, explaining its role as the entry point for air and the importance of nasal breathing over mouth breathing due to the filtering and warming functions of the nasal passages. Hairs and mucus in the nose trap foreign particles, preventing them from entering the body, and the nose also warms the air to maintain body temperature.

05:00

🔍 The Journey of Air Through the Respiratory System

Continuing the exploration, Miss Angler describes the path air takes from the nostrils, through the nasal passages, and down the throat. She explains the benefits of nasal breathing, including the filtering action of nose hairs and mucus, and the warming effect on the air. The video then transitions to discussing the structures encountered as air moves towards the lungs, including the larynx and the trachea. The larynx, or voice box, is distinguished from the pharynx, which is associated more with the digestive system. The trachea, or windpipe, is highlighted for its cartilaginous rings that keep it open for airflow, and its lining of mucus to trap particles. Miss Angler also mentions her study guide available on her website for those interested in further study materials.

10:02

🫁 Deeper Insights into Lung Structures

The video delves deeper into the respiratory system, focusing on the lungs and their structure. Miss Angler points out the differences between the left and right lungs, noting the varying number of lobes and the reasons behind these differences, such as the space occupied by the heart. She also discusses the diaphragm's role in breathing, moving up and down to facilitate the inhalation and exhalation process. The protection mechanisms for the lungs are also covered, including the pleura membrane and the fluid it secretes to reduce friction, as well as the protective role of the ribs and intercostal muscles. The bronchi, which are the main branches of the trachea leading into the lungs, are introduced, emphasizing their ciliated cells designed to trap and move foreign particles away from the lungs.

15:03

🌬️ Gaseous Exchange in the Alveoli

Miss Angler concludes the video by zooming in on the bronchioles and alveoli, the tiny air sacs where gas exchange occurs. She explains the importance of the alveoli's structure, including their large surface area, thin walls consisting of a single cell layer, and the presence of a moisture layer, all of which facilitate efficient gas exchange. The necessity of a capillary network around the alveoli for gas transport is also mentioned. The video wraps up with a discussion on the requirements for gaseous exchange, such as adequate ventilation provided by the diaphragm and intercostal muscles, and protection mechanisms like the pleura membrane and cartilage. Miss Angler stresses the importance of understanding these structures for exams and provides a terminology recap, encouraging the use of flashcards for learning. She ends the lesson with a reminder to like and subscribe for more educational content.

Keywords

💡Respiratory System

The respiratory system is a biological system consisting of specific organs and structures that allow an organism to take in oxygen and release carbon dioxide. In the video, the respiratory system is the central theme, with a focus on its various structures and their functions, particularly in facilitating gas exchange.

💡Nose

The nose is the initial entry point for air into the respiratory system. It is equipped with hairs and mucus to filter out dust and foreign particles, ensuring that the air is clean before it enters the lungs. The video emphasizes the importance of breathing through the nose for proper filtration and warming of the air.

💡Mucus

Mucus is a slimy substance found throughout the respiratory system, composed of water and proteins. Its primary function is to trap dust, bacteria, and other particles to prevent them from entering the body. In the context of the video, mucus in the nose and trachea is highlighted as a crucial defense mechanism.

💡Larynx

The larynx, often referred to as the voice box, is a cartilaginous structure that houses the vocal cords. It is part of the respiratory system and plays a role in both breathing and speech. The video distinguishes the larynx from the pharynx, noting its importance in language and speech production.

💡Trachea

The trachea, or windpipe, is a tube that connects the larynx to the bronchi and serves as the main passage for air to reach the lungs. It is held open by cartilaginous rings to ensure unobstructed airflow. The video explains the trachea's role in the respiratory system and its structural support.

💡Bronchi

Bronchi are the two main branches of the trachea that lead into the lungs. They are lined with ciliated cells to trap and move foreign particles, preventing them from entering deeper into the lungs. The video describes the bronchi as the conduits for air to reach the smaller airways within the lungs.

💡Lungs

Lungs are the primary organs of the respiratory system where gas exchange occurs. They contain numerous alveoli and are protected by the ribcage and the diaphragm. The video notes that the left lung has two lobes and the right lung has three, with differences attributed to the space occupied by the heart.

💡Diaphragm

The diaphragm is a muscular sheet that separates the thoracic cavity from the abdominal cavity. It plays a critical role in the breathing process by contracting and relaxing to facilitate the inhalation and exhalation of air. The video highlights the diaphragm's function in the respiratory mechanism.

💡Alveoli

Alveoli are tiny air sacs at the end of the bronchioles where the actual gas exchange occurs. They are characterized by a large surface area, thin walls, and a moist environment, which are all conducive to efficient gas exchange. The video emphasizes the structural features of alveoli that make them suitable for their function.

💡Gas Exchange

Gas exchange is the process by which oxygen is taken into the bloodstream and carbon dioxide is expelled from the body. This process occurs in the alveoli of the lungs. The video discusses the requirements for efficient gas exchange, such as a large surface area, thin walls, and the presence of a moist layer in the alveoli.

💡Pleura

The pleura is a protective membrane that covers the lungs and lines the inside of the thoracic cavity. It secretes a lubricating fluid to reduce friction between the lungs and the chest wall during breathing. The video mentions the pleura as part of the body's protective mechanisms for the lungs.

Highlights

Introduction to the respiratory system covering structures, functions, and gaseous exchange.

Nasal breathing is preferred due to its role in filtering, warming, and humidifying the air.

Nose hairs and mucus serve as the body's first line of defense against foreign particles.

The importance of nasal breathing for maintaining body temperature by warming the air.

Differences between the larynx and pharynx in terms of function and anatomy.

The trachea's structure, supported by cartilaginous rings, and its role in air passage.

Mucus in the trachea helps trap particles and provides lubrication for easy movement.

The lungs' structure, including the number of lobes and their protective mechanisms.

The diaphragm and intercostal muscles' crucial role in the breathing process.

Pleura membrane and pleural fluid's function in reducing friction around the lungs.

The bronchi and bronchioles as conduits for air to reach the alveoli.

Ciliated cells in the bronchi and their function in trapping and moving particles.

Alveoli as the primary site for gaseous exchange and their structural adaptations.

Requirements for efficient gaseous exchange within the alveoli, including a large surface area and thin walls.

The presence of a moisture layer in the alveoli facilitating gaseous exchange.

Capillary network around the alveoli allowing for efficient gas and oxygen exchange.

Adequate ventilation and protection as essential for the respiratory system's function.

Terminology recap emphasizing the importance of understanding respiratory system components.

Transcripts

hi everybody and welcome back to miss

Angler's biology class I am Miss angler

in today's video we are going to be

doing an introduction to the respiratory

system and in this video we are going to

cover the various structures and their

functions and annotate them as well as

looking at the various ways in which

your respiratory system is suited for

gases exchange please know though that

other videos are going to do more detail

about the processes like gaseous

Exchange in more detail so if you want

to find those you can see them now

linked above or you can go and check out

the grade 11 playlist now if you are new

here don't forget to give this video a

thumbs up and make sure you are

subscribed because I post every Tuesday

and Thursday for grades 10 to 12 life

sciences

so let's begin our journey with the nose

now what you can see in front of you

here is a cross section through the side

of a human's skull and face and that is

where we see our nose over here so this

is the opening to our nose these are the

nostrils and that is where air is going

to enter into your respiratory system

now it is better to breathe through your

nose and this is why ultimately when air

moves through the nose it has to bypass

a few obstacles as well as moving

through the sinuses and the reason why

this is a good thing and to breathe

through your nose rather than through

your mouth is because there are a few

things in there that are going to stop

infections and also we want to warm the

air so the first thing that's inside

your nose is hairs now I know that a

nose hair doesn't feel like it's got a

job but it does ultimately nose hairs

are there to trap any foreign particles

from moving deeper into your nasal

passage they are all also there so that

if mucus collects on it they have

something to attach to so that when a

particle like a virus or a bacteria

moves through your nasal passage it gets

stuck on the hairs and the mucus on the

hairs and then doesn't go any further

which of course then brings me to the

other thing that we often find inside of

our nose which is mucus now to remind

you mucus is just like a secretion a

little bit of water a little bit of

protein that you secrete and its main

function is to trap dust viral and

bacterial particles fungal spores to

because ultimately once it is inside

your body you then have to rely on your

second and third line of defense in your

immune system which requires a lot more

effort and specialization so we want to

stop that first the third thing why it's

important to breathe through your nose I

just mentioned to you now is that when

you breathe through your your nose it

has a warming effect on the air and now

this is important because remember we

want to keep the body a nice 37 degrees

and the only way to do that is to warm

the air when it enters

um and so that's why it's better to

breathe through your nose than through

your mouth now once the air has moved

through your nose or nasal passages it's

going to go down the back of your throat

and it's going to make its way down to

the track here now of course you can

also breathe through your mouth which is

actually just located here below your

teeth and that can also enter into the

back of your throat where you can

breathe if your nose is blocked

before I move on grade 11s I also want

to remind you that I have my grade 11

cheat sheet study guide and you can get

your hands on that at my website which

is Miss

angler.co.za it makes studying so easy

so simple it's not like a textbook it

truly is a cheat sheet to studying I've

summarized everything I've left out

everything that you don't need to know

everything that's not important and it

just makes your life so much easier and

you can find that once again on my

website Miss angler.co.za

now that the air is making its way down

to your lungs it's going to go past

various structures starting off with the

larynx which is this structure we see up

over here now we often get the larynx

and the pharynx confused the easiest way

to tell the difference between the two

is that the larynx I like to think of as

language like the two letter L's because

that is where you speak from that is

where your vocal cords are located it's

where what you would call your Adam's

apple is and so I like to think of

larynx is for language speaking and the

pharynx is for food that is the other

passageway where food will go back down

the back of your throat and into the

esophagus but I'm not going to mention

too much of the pharynx because it's

more associated with our digestive

system

now as a pass is past the larynx it's

going to move down into this tube here

and this is called the trachea

now the trachea is held open by

cartilaginous rings and these

cartilaginous Rings give support and

structure to the trachea so that your

passageway stays open until yet you can

breathe now the trachea is also lined in

mucus as well and that is again to trap

any foreign particles from making their

way down into the trachea

now this mucus

um originates some of it in your nose

but also the glands or the little

globular cells and we call them goblet

cells you may remember them they are the

ones that can secrete mucus and it's

also just there for a little bit of

lubrication as well it makes it easy to

move around any particles now moving on

to the bigger structures as our air

moves down our trachea it's going to

Branch off either to the left or to the

right now I'm going to get to those

names shortly because we're going to

zoom in closer so you can see them let's

do the bigger stuff first first of all

the most obvious thing that we can see

here is the lungs now you have two lungs

as you can see here you have a left and

a right lung and the lungs themselves

are actually slightly different sizes

and they have different amounts of lobes

you will notice the lung on the right of

the body and yes that is the right side

of the body because remember it's the

opposite in a person and then your your

hands it's not your right it's the

person's right they have three lobes one

two three versus the left lung only has

two and the lobes that I'm referring to

are these little sections that you can

see here

and I want you to think of a lobe as

being like a region or an area and the

reason why the left one is a little bit

smaller is because we've got to put the

heart in this space over here now

another structure that we see in this

diagram is the diaphragm and it's

obviously very very very closely related

to the breathing mechanism because

remember the diaphragm is that muscle

that moves up and down and it allows you

to breathe now protecting the lungs

there are two things we need to be aware

of first of all it is this faint sort of

pink line that we can see on the outside

here and that is called the pleura or

the pleura membrane and the pleura or

the pleural membrane secretes a fluid

and that fluid is to prevent friction

and as we know

um

the lungs I'm losing every single day

and so we don't want to have too much

friction and and literally burn or waste

away deteriorate the lung tissue so

we've got to put them in these like

little skin-like bags and we fill it

with a little bit of fluid so that

there's a little bit of lubrication and

so that there's no friction now the last

thing I need to mention in terms of

protecting our thoracic cavity and our

lungs is going to be a combination of

two things which are these bones as well

as the muscles that sit in between them

you may remember these

as the ribs and the intercostals now the

ribs and intercostal muscles are there

for protection but they're also really

important breathing structures because

they are the ones that initiate making

the thoracic cavity bigger so that you

can start pulling in air and breathing

now as I did mention earlier in the

video I wanted to zoom in a little bit

closer on the the branches of the

trachea as they get smaller and so what

we've done is we have removed the um

lungs and everything else so you can

just see the trachea and the tubes that

come out of the track here so here yet

again is the track here and the air is

now moving down now the air is going to

Branch off to the left and it's going to

Branch off to the right and these two

bigger branches they are referred to as

the bronchus or the bronchi just depends

on whether you're talking about one or

two and they are right at the end of the

track here they've got a little bit of

cartilage left on them not too much most

importantly they are lined with ciliated

cells now if you've forgotten what

ciliated cells are those are the cells

that have teeny tiny little hairs on the

ends of them so if that's the cell

they've got these little hairs that

stick off of them again remain as the

same function that the actual hairs and

your nose have these little sillier

hairs are there to trap dust mucus and

particles just to make sure that you

know any foreign substances

um spores viruses bacteria they don't go

deeper and deeper into your lungs now

these little bronchies they get smaller

into these very fine little branches

that you can see here and so that's all

the directions that air can take those

small little branches those are called

the bronchioles now the bronchials are

very very small

um and they don't have a very thick

walls so they're very thin

and they have very uh little or less

cartilage they basically get less and

less around them uh the deeper that we

go

and it makes sense because

um the cartilage would get in the way of

gaseous exchange now again we need to

zoom in even further because sitting at

the ends of the bronchioles which means

sitting at the end of each one of these

which is where I'm drawing these black

circles should be our gaseous exchange

surface or the alveoli but we need to

get even closer

so now that we have zoomed in even

closer we can finally see the very end

of the bronchials so air is moving down

this little bronchial and it branches

off into each of these alveoli and so

what we are looking at here is an lvo

list or an lvoli just depends if you're

talking about one or many and this is

where gaseous exchange occurs now I have

a different video for you to go and

watch if you want to learn more about

yasu's exchange I have linked it up

above now and it's important to know why

the alveoli are structured the way they

are as well as why the the respiratory

system is structured the way it is so

the most important conversation we must

have is what are the requirements for

gaseous exchange to happen inside the

alveoli now you'll notice the alveoli

are like clusters of circles and those

little clusters of circles you can see

we've cut them open here so we can see

on the inside side this fulfills one of

the main requirements for gaseous

exchange which is there must be a large

surface area so that's really important

when it comes to gaseous exchange we

need a big surface area so the alveoli

do that really well the next thing that

we need when it comes to

good gases exchange is it needs to be a

thin surface now I don't know if you

know this but alveoli are one

cell layer

thick okay they are very very thin and

very very small which basically means

alveoli are basically microscopic if

they are that thin and they need to be

thin for efficient diffusion because the

more cells the slower diffusion occurs

so by making them only one cell layer

thick it means that if this is the

layers of cells that make up the alveoli

and this is the bloodstream moving past

it then the gas just has to Simply move

through only one layer to get into your

bloodstream

now the next requirement that alveoli

fulfill out of the requirements for

gaseous exchange is that they have a

moisture layer and it's a little bit

omitted or missing in this picture but

essentially what that means is is there

is a thin layer of moisture sitting on

the inside of these alveoli over here

and that is really important it's not a

lot that you would be drowning but it is

definitely just enough so that gaseous

exchange can occur so there is moisture

inside of your alveoli

the next thing that your alveoli have

which is another requirement of gaseous

exchange is they are able to transport

gases really well now what's missing on

this picture but I want you to imagine

that it is there is a capillary Network

and this capillary network runs all on

the outside of each of these alveoli and

that allows for efficient gases exchange

to occur because it allows for carbon

dioxide to leave the blood and oxygen to

enter the blood now the next two things

that are required for gaseous exchange

are a little bit abstract because we

can't see them directly in this image

but in order for gas this exchange to

occur properly we need something called

adequate ventilation which basically

means you need a mechanism to help you

breathe and we do have adequate

ventilation because that is what is used

by the intercostal muscles and the

diaphragm they are the ones that allow

you to ventilate to bring air in and out

so we do have that and and the last

requirement for gaseous exchange is you

need adequate protection again this is

not really shown so much in this image

but the protection comes from your

cartilage from the pleura membrane and

the pleural fluid around your lungs as

well as the ribs so we have these six

things that we need to know and I just

want to stress how important it is to

know all six for your exams because they

often ask you like name or three ways

um the alveoli is structured for gaseous

exchange and you've got to use three

from this list that are appropriate I

wouldn't say that the last two would

match up with the alveoli they match up

with the respiratory system as a whole

but definitely the first four could be

the answers that you give and please

also remember they often ask you to name

and explain so what that means is you

can't just say large surface area you

must say large surface area and then

elaborate on that it explain it a bit

more what does it mean to have a large

surface area like how do they have it

now as always I'd like to finish off my

lessons with the terminology recap and

this is looking back at all the words we

used today remember that if you are

unable to do terminology and terminology

sections then you won't be able to do

the rest of the harder questions and you

won't be getting full marks with your

explanations so use these words in the

form of flashcards it makes it really

really easy to learn from starting off

with the nose of course this is the

structure that we want to breathe with

it has lots of hairs mucus to trap dust

and foreign particles mucus is of course

that protein and water mixture that we

have everywhere in our nose our throat

pharynx larynx all the way down to the

track here and lungs speaking of larynx

and pharynx remember the larynx is where

you speak from it's your voice box it's

where language comes from it's your

cartilaginous voice box the pharynx is

the back of the throat more associated

with swallowing and going down into the

food or esophagus tube we then had the

trachea which is your windpipe but I

don't like using that word and so we

don't want to use it in exams please

um the trachea is surrounded by

cartilage which holds it open

then getting down into the bigger

structures the plural was that membrane

that sits around your lungs like a bag

it protects your lungs against friction

the lungs themselves are divided into

lobes which are like regions

and then we had the diaphragm which is

along with the intercostal muscles or

the muscles that sit around your lungs

and help you breathe and then we zoomed

into the very small structures which are

the bronchi another bronchie or the

little tubes that come down from the

trachea so it sort of goes trachea

bronchie then bronchioles which are the

smallest tubes and then right at the end

of each of those bronchioles there's a

teeny tiny little alveoli which is the

site of gaseous exchange now if you like

this video make sure to give it a thumbs

up and turn your notifications on so you

know when I post new content every

Tuesday and Thursday and I will see you

all again soon grade 11's bye

[Music]