Upper Respiratory Tract Anatomy | Anatomy & Physiology for Nurses

Summary

The video provides a detailed overview of the respiratory system, emphasizing the structures and functions involved in gas exchange with the blood. It begins with the anatomy of the nasal cavity, larynx, and progresses to the trachea, bronchi, and lungs, explaining their roles in air modification and filtration. Key components like the pleura, diaphragm, and phrenic nerve are discussed, alongside the protective mechanisms preventing food and water from entering the lungs. The video also covers the larynx's role in vocalization, with a focus on the vocal cords and their functions during speech and breathing, setting the stage for further exploration of the lower respiratory tract.

Takeaways

• 🫁 The respiratory system's primary goal is gas exchange with the blood, involving many structures that modify air before reaching the lungs.
• 👃 The nasal cavity plays a crucial role in warming, humidifying, and cleaning the air before it passes deeper into the respiratory system.
• 🗣️ The larynx is involved in vocalization and protects the airway during swallowing, with the epiglottis playing a key role in preventing food from entering the lungs.
• 🌬️ The upper respiratory tract includes the nasal sinuses, nose, nasal cavity, pharynx, and larynx, while the lower tract begins with the trachea and bronchi.
• 👃 The nasal septum divides the nasal cavity into left and right, and turbinates (nasal conchae) help in conditioning the air before it enters the lungs.
• 🔍 The nasal cavity is surrounded by sinuses, which are lined by mucous membranes and may contribute to voice resonance and reducing head weight.
• 👃 Olfactory mucosa in the nasal cavity is responsible for the sense of smell, with olfactory nerves passing through the skull to the brain.
• 🍽️ The pharynx serves as a shared passageway for air and food, with the soft palate and epiglottis ensuring food and air go to their respective paths.
• 🎤 The vocal cords, located in the larynx, are responsible for producing sound, with the false vocal cords located above the true vocal cords.
• 💉 Intubation involves inserting a tube past the true vocal cords into the trachea to ensure an open airway for artificial breathing support.

Q & A

What is the primary goal of the respiratory system?

The primary goal of the respiratory system is to achieve gas exchange with the blood.

What structures are involved in moving and modifying air before gas exchange?

The nasal cavity, larynx, trachea, bronchi, hilum, pleura, and major blood vessels are involved in moving and modifying air before gas exchange occurs in the lungs.

What are the key structures of the upper respiratory tract?

The upper respiratory tract consists of the nasal sinuses, nose, nasal cavity, pharynx, and larynx.

What is the function of the nasal conchae or turbinates?

The nasal conchae or turbinates help warm, humidify, and clean the air as it enters the nasal cavity. They also direct air upwards to the olfactory mucosa for the sense of smell.

What is the significance of the olfactory mucosa in the nasal cavity?

The olfactory mucosa is responsible for the sense of smell. It contains tiny nerves that make up the olfactory nerve, which sends smell signals to the brain.

How does the respiratory system prevent food and water from entering the lungs during swallowing?

During swallowing, the soft palate prevents food from entering the nasal cavity, and the epiglottis covers the airway, directing food into the esophagus instead of the lungs.

What is the role of the epiglottis in the respiratory system?

The epiglottis is a flap of tissue that covers the airway during swallowing to prevent food and water from entering the lungs.

What are the vestibular folds and vocal folds in the larynx?

The vestibular folds, also called false vocal cords, do not produce sound, while the vocal folds (true vocal cords) vibrate to create vocalization or speech.

What is the difference in appearance between the false vocal cords and true vocal cords?

The false vocal cords are pink, while the true vocal cords are bright gray or white, making them visually distinguishable.

Why is it important to identify the true vocal cords during intubation?

During intubation, it is important to identify the true vocal cords because the cuff of the intubation tube must expand below the true vocal cords to ensure a clear airway for artificial breathing.

Outlines

00:00

👃 Anatomy and Function of the Nasal Cavity

The paragraph introduces the respiratory system's primary function of gas exchange with the blood. It then delves into the structure and function of the nasal cavity, which is the respiratory system's starting point. The nasal cavity is composed of cartilage at the front, providing flexibility, and bone at the back, offering rigidity. Inside, the cavity is divided by the bony septum into left and right sections. The nasal cancha or turbinates, which are uniquely shaped bones, line the cavity walls and play a crucial role in warming, humidifying, and cleaning the air. Additionally, the nasal cavity is surrounded by sinuses, which are spaces within the bone that can become inflamed due to infections. The olfactory mucosa, responsible for the sense of smell, is located at the top of the nasal cavity, and the olfactory nerves, part of the first cranial nerve, pass through this area to reach the olfactory bulb in the brain.

05:00

🍽 The Balance Between Breathing and Eating

This section discusses the coordination between the respiratory and digestive systems, particularly in the pharynx where both air and food pass. It explains the mechanism that prevents food and water from entering the lungs during swallowing. The soft palate and epiglottis act as barriers, directing food into the esophagus and protecting the airway. The paragraph also describes the anatomy of the larynx, including the hyoid bone, vestibular folds (false vocal cords), and the true vocal cords, which are essential for speech and can close off the airway if necessary. The view through the mouth towards the larynx is highlighted as crucial for medical procedures like intubation, where the distinction between true and false vocal cords is vital for successful airway management.

10:01

🗣️ The Larynx and Lower Respiratory Tract

The final paragraph focuses on the larynx's role in protecting the airway and producing sound. It describes the larynx's anatomy, including the epiglottis, vestibular folds, and vocal folds. The true vocal cords are highlighted for their distinct appearance and function in voice production. The paragraph also transitions to the lower respiratory tract, starting with the trachea, which provides a clear pathway for air to reach the lungs. The importance of the true vocal cords in intubation is reiterated, as they must be bypassed to ensure unobstructed airflow. This section sets the stage for further discussion of the lower respiratory system in subsequent content.

Keywords

💡Respiratory System

The respiratory system is responsible for gas exchange between the air and blood. The video focuses on the structures that facilitate this process, including the nose, nasal cavity, trachea, and lungs. It highlights the system's function of delivering oxygen to the bloodstream and removing carbon dioxide.

💡Nasal Cavity

The nasal cavity is the passage through which air enters and is processed before reaching the lungs. It is lined with mucosa and contains structures like the nasal conchae that help warm, humidify, and clean the air. The video discusses how the nasal cavity's structure aids in preparing air for gas exchange.

💡Larynx

The larynx, also known as the voice box, is a structure located below the pharynx that plays a key role in both respiration and vocalization. It houses the vocal cords and is protected by the epiglottis, which prevents food from entering the airway. The larynx is essential for sound production and protecting the respiratory tract.

💡Trachea

The trachea, or windpipe, is the tube that connects the larynx to the bronchi, allowing air to move between the upper respiratory tract and the lungs. The video explains its role in the lower respiratory system, ensuring that air travels efficiently to the bronchi and lungs for gas exchange.

💡Bronchi

The bronchi are the two large tubes that branch from the trachea into each lung, transporting air deeper into the lungs. They further divide into smaller bronchioles, leading to the alveoli where gas exchange occurs. The video highlights their role in directing air to the lungs' functional areas.

💡Nasal Conchae

The nasal conchae, or turbinates, are curved bones inside the nasal cavity that create turbulence in inhaled air. This helps to warm, humidify, and filter the air before it reaches the lungs. The video emphasizes their importance in optimizing the air quality for respiration.

💡Pleura

The pleura are two layers of tissue that surround the lungs and line the chest cavity, creating a fluid-filled space that allows the lungs to expand and contract smoothly during breathing. The video describes the pleura’s role in protecting the lungs and reducing friction during respiration.

💡Diaphragm

The diaphragm is the major muscle responsible for breathing. It contracts to expand the chest cavity and pull air into the lungs and relaxes to push air out. The video discusses how the diaphragm works with the respiratory system to facilitate the mechanics of breathing.

💡Phrenic Nerve

The phrenic nerve controls the diaphragm, allowing it to contract and enable breathing. The video highlights its importance in respiratory function, as without the phrenic nerve, the diaphragm would not work properly, compromising the body’s ability to breathe.

💡Olfactory Nerve

The olfactory nerve, or the first cranial nerve, is responsible for the sense of smell. Located in the upper part of the nasal cavity, it sends signals to the brain about odors. The video mentions the olfactory mucosa and its function in detecting smells, connecting it to the broader discussion of the nasal cavity's functions.

Highlights

Introduction to the respiratory system's goal of gas exchange with the blood.

Explanation of nasal cavity structure and function, and its role in modifying air before it reaches the lungs.

Detailed description of the larynx and its role in both respiration and vocalization.

Overview of the trachea, bronchi, and their connection to the lungs.

Introduction to the pleura, the membranes surrounding the lungs and chest cavity.

Mention of the diaphragm and the phrenic nerve as major components of respiration.

Division of the respiratory tract into the upper and lower portions.

Detailed anatomy of the nasal sinuses, including their unknown functions and connection to the respiratory system.

Explanation of the role of nasal turbinates (or conchae) in warming, humidifying, and cleaning inhaled air.

Introduction to olfactory mucosa and its role in the sense of smell.

Discussion of the shared oral, digestive, and respiratory space and the role of the epiglottis in preventing food from entering the airway.

Overview of the larynx's role in speech production, specifically the vocal cords.

Description of the vestibular (false) vocal cords and their role compared to the true vocal cords.

Explanation of the view seen during intubation, highlighting the appearance and function of the true and false vocal cords.

Transition to the lower respiratory tract and the trachea as the clear path for air into the lungs.

Transcripts

Now, we're going to talk about the respiratory system,

whose goal ultimately is to achieve gas exchange with the blood.

But there are many important structures that move and modify air

before it gets to that point.

So we're going to start by talking about

the structure and function of the nasal cavity

before moving a little bit deeper down to talk about the larynx.

Then once we get into the chest cavity,

we're going to be talking about the trachea, bronchi,

something called the hilum

and the major blood vessels that supply the lung.

We're going to talk about the wrappings of the lung

and the chest cavity called the pleura.

We're going to talk about superficial anatomy of the lungs,

as well as bony thorax that encases the lungs.

And then finally, we're going to talk about

the major muscle of respiration, which is the diaphragm

and the nerve that innervates it, which is the phrenic nerve.

The respiratory tract itself can be divided into

an upper and lower portion.

The upper portion consists of nasal sinuses, nose, the nasal cavity,

a shared oral, digestive, and respiratory space

called the pharynx. And then the larynx.

After which, we have the lower respiratory tract

starting with the trachea that divides into bronchi

to supply the lungs.

We're going to focus first on the upper respiratory tract.

In particular, we're going to start with the nose and nasal cavity.

And this anterior view of a skull,

we see that the anterior most portion of the nose

isn't actually made up of bone, but it's made up of cartilage

what makes it very flexible and very movable.

Further back, we do have bone that's connected to the rest of the skull.

If we were to take off that cartilage,

and look into the nasal cavity itself,

we see that there's a wall

at this point made up of bone called the septum

that divides the cavity into left and right cavities.

We also noticed that laterally on each nasal cavity wall,

we have these weird shaped bones called nasal cancha, or turbinates,

that have that shape to help achieve their very important functions.

Now let's look at a sagittal view right down the midline.

And we're going to look towards the septum from the left side.

Anteriorly, it's again made up of cartilage,

which gives it the flexibility that you're probably familiar

with the external nose.

But further back, it's made up a bone so it's rigid.

Now, if we were to take a coronal section,

somewhere around this bony septum,

we see there's actually a lot of spaces here.

So we again find the bony septum in the midline,

separating the cavity into left and right.

And we again see these weird shaped bones

coming off of the lateral wall,

the cancha or turbinates,

and we see that they're named for their location.

We have a superior, a middle,

and an inferior nasal chancha on either side.

We also noticed surrounding the nasal cavity,

the spaces within the bone called sinuses.

and they're lined by mucous membranes

that are made up of the same type of epithelium

as the rest of the nasal cavity.

And their function is somewhat unknown.

We don't really know there are a lot of theories.

For example, these spaces helped make the head lighter.

They add resonance to the voice.

Regardless of what they're really doing there,

they are important because they are connected to these nasal cavities.

And therefore, infections, for example, can spread into them

and cause inflammation or sinusitis.

Let's go back to this midline sagittal view

where we again see the nasal septum.

This time in pink because we've covered it with some mucosa.

If we were to take away that septum

by moving just a little bit to the right of midline.

And again, taking it from this view from the left,

we will now see the right lateral wall of the nasal cavity.

Now, we can see these conquer or turbulence.

We see the superior, the middle, and the inferior nasal turbinates here.

And there's a lot of functions to these turbinates.

For example, the air we breathe in is fairly dirty,

It's fairly dry and it's fairly cold compared to the rest of the body.

And they actually create turbulence

in conjunction with the mucosa that lines these

helps to warm the air, humidify it, and help clean it.

It also helps to direct air upwards to the top of the nasal cavity,

where we have a special type of mucosa called olfactory mucosa.

And olfactory means smelling.

So this area is a specialized area for smell.

And in fact, in this area,

there are a bunch of tiny nerves that collectively make up

the first cranial nerve or olfactory nerve,

which is the nerve of smelling.

And these tiny little nerves pass through the school at this area

to reach the cranial cavity

at a special spot called the olfactory bulb,

which will then have attracted that goes back to the brain

to process the sense of smell.

Let's look at a bit of a complicated issue here

when we talk about breathing and eating.

So we just talked about air moving through the nasal cavities,

and its objective is to ultimately get down into the lungs.

However, we also have an oral cavity

through which things like food and water going to pass.

Eventually, back to the esophagus into the stomach.

But this creates a problem because as you can see,

there's a space where both food and water are shared with air.

And so how do we prevent things like food and water

from ending up in the lungs and essentially choking us.

So let's look what happens

when we try to swallow a portion of food.

When we've chewed up a bit of food, it formed something called a bolus.

And it's held in place here by the tongue.

If we look posterior to this,

we see that there's an area of the palate that lacks bone.

And that's the soft palate.

And more inferiorly at the base of the tongue,

we have this little flap of tissue called the epiglottis.

During the act of swallowing,

the tongue and several other muscles push this bolus back posteriorly.

And the soft palate acts as a flap to prevent food

from going up into the nasal cavity.

While the epiglottis,

serves to flap down and protect the opening to the airway

as food is being swallowed.

Therefore, it forces food posteriorly

and back into the esophagus where it belongs.

Now, let's move down a little bit further

and talk about the larynx.

Here we have a nice sagittal view

that zoomed in a little bit here.

So we could see just a little bit of the base of the tongue here.

So this is the most posterior inferior portion of the tongue.

We also see a unique bone in the neck called the hyoid bone.

And we see that flap of tissue

that helps move food posterior into the esophagus,

therefore protecting our airway, which was the epiglottis.

And from here, we're going to start seeing the larynx.

A little bit further down, we have a fold called the vestibular fold.

And just below that we have something called the vocal fold.

As you might guess, by the name, the vocal fold is actually

what's going to help create vocalization or speech.

And then beyond the larynx,

we finally have the lower respiratory tract

starting with the trachea.

And again, posterior to the trachea is going to be the esophagus,

on its way down to the stomach.

Here we have a view from posterior,

where we've opened up the larynx to look towards it.

So we could actually see all of the epiglottis here

as this little flap that will come down and protect the airway.

And as we go down a little bit,

we see both of these folds that we called vestibular folds.

And we also call them false vocal cords

because they look very similar in location

at least to the vocal cords,

but they're not producing any sound.

And it's actually just below these that we have the true vocal cords

that are the ones that are going to vibrate and produce sounds.

When we take a scope and look down through the mouth

down towards the larynx,

this is the typical view you're going to have.

And this is an important view because

this is the view you would have if you were trying to intubate someone

who wasn't able to protect their airway

and needed some sort of artificial help with breathing.

And this case, we see that the vocal cords are abducted

or pulled away from midline.

Therefore they're open and air can move in and out.

And from this view, you can see that the false vocal cords

or the vestibular folds are not only more superior,

but they're actually not coming close to midline

as much as the true vocal cords.

You also see that unlike the false vocal cords that are very pink,

the true vocal cords are very bright gray or white.

So they have a lot of different appearances

to distinguish them from the false vocal cords,

which is useful when you want to intubate.

Because when you intubate,

you want to get the cuff that's going to expand

beyond the true vocal cords.

Because beyond that point,

as long as you have some sort of way to deliver air,

nothing is going to obstruct it from moving up and down.

And that's because at this point,

the true vocal cords can become adducted

or come together and close off the airway.

Beyond this point, we start the lower respiratory tract

with the trachea and have a clear path down into the lungs,

which we'll talk about in the next section.