Clinical Anatomy - Nasal Cavity and Sinuses

Summary

This video delves into the clinical anatomy of the nasal cavity, highlighting the sinuses. It explains the nasal cavity's structure, including the hard and soft palates, and the pharynx's three parts. Key sinuses like the frontal and sphenoid are discussed, along with the eustachian tube's connection to the ear. The video also covers the turbinates' role in warming and moistening air, and the olfactory segment's function in smell. It concludes with potential sinusitis complications, such as infection spreading to the eye or brain.

Takeaways

• 👃 The nasal cavity is bordered by the palate, which includes a hard bony palate anteriorly and a soft palate posteriorly.
• 🗣️ The pharynx, or throat, is divided into three parts: the nasal pharynx, oral pharynx, and laryngopharynx.
• 🧠 The brain sits in the cranial cavity, with a small hole in the skull leading to the frontal sinus.
• 🕳️ The sphenoid sinus is located posterior and superior to the nasal cavity.
• 👂 The eustachian tube connects the middle ear to the nasal cavity, allowing for potential ear infections from upper respiratory infections.
• 🌬️ Turbinates, or nasal conchae, warm and moisturize the air passing through the nose.
• 💧 The nasal meatus is where sinuses drain, indicating a connection between the sinuses and the nasal cavity.
• 🍃 The nasal cavity has a respiratory segment for air exchange and an olfactory segment for smell, lined with specialized cells.
• 🧠 The olfactory nerve, cranial nerve number one, carries smell signals from the olfactory segment to the brain.
• 🏔️ The sella turcica is the pituitary fossa where the pituitary gland is encased.
• 🤧 Rhinitis, or inflammation of the nasal mucosa, can lead to sinusitis, inflammation of the sinuses.
• 🔥 Complications of sinusitis can include blindness, optic neuritis, osteomyelitis, meningitis, and brain abscesses, although these are rare.

Q & A

What are the primary structures bordering the nasal cavity?

The nasal cavity is bordered by the palate, which consists of a hard bony palate anteriorly and a soft palate posteriorly, the oral cavity, the pharynx, and the nasal pharynx.

What is the function of the epiglottis?

The epiglottis acts as a gateway to the trachea, connecting the lungs, and closes during swallowing to prevent food from entering the trachea.

What is the clinical significance of the Eustachian tube?

The Eustachian tube connects the middle ear to the nasal cavity, allowing for equalization of air pressure. An upper respiratory tract infection can travel through this tube and cause a middle ear infection.

What are the turbinates and their function?

The turbinates, also known as nasal conchae, are structures within the nasal cavity that help warm and moisturize the air as it passes through the nose.

How do the sinuses drain into the nasal cavity?

The sinuses drain into the nasal cavity through the nasal meati. For example, the sphenoid sinus drains into the superior meatus, and the frontal sinus drains into the middle meatus.

What is the olfactory segment of the nasal cavity responsible for?

The olfactory segment is responsible for the sense of smell. It is lined with pseudostratified columnar epithelium containing receptors for smell.

What is the sella turcica and its relation to the pituitary gland?

The sella turcica, or 'Turkish saddle', is the pituitary fossa where the pituitary gland is located. The gland is encased by the sella turcica but does not sit directly on it.

What is rhinitis and how can it lead to sinusitis?

Rhinitis is the inflammation of the mucosal membranes in the nose. Since the nose and sinuses are connected, rhinitis can spread to the sinuses, causing sinusitis.

What are the potential complications of sinusitis?

Complications of sinusitis can include the spread of infection to the eye, causing blindness or optic neuritis, and in severe cases, osteomyelitis of the frontal sinus or meningitis.

How does a coronal section of the nasal cavity provide a different view of the sinuses?

A coronal section of the nasal cavity provides a view from the front, showing the relationship between the nasal cavity, sinuses, and other structures such as the orbit and maxillary sinus.

What is the difference between rhinitis and sinusitis?

Rhinitis is inflammation of the nasal mucosal membranes, while sinusitis is inflammation of the sinuses. Rhinitis can lead to sinusitis due to the connected nature of the nasal and sinus cavities.

Outlines

00:00

👃 Anatomy of the Nasal Cavity and Sinuses

This paragraph discusses the clinical anatomy of the nasal cavity, focusing on the sinuses. It begins by describing the nasal cavity's structure, including the hard and soft palates, the oral cavity, and the epiglottis. The pharynx is divided into the nasal, oral, and laryngopharynx. The brain's position relative to the nasal cavity is mentioned, along with the presence of sinuses like the frontal and sphenoid sinuses. The paragraph also covers the eustachian tube's connection to the middle ear and the role of turbinates in warming and humidifying air. The nasal meatus and their relationship with sinus drainage are explained. The olfactory segment's role in smell is highlighted, along with the sella turcica's function and the potential complications of rhinitis and sinusitis.

05:01

🔍 Exploring Sinusitis and Its Complications

The second paragraph delves into the anatomy of the nasal cavity and sinuses from a coronal section perspective, detailing the positions of the superior, middle, and inferior turbinates, as well as the sinuses. It discusses sinusitis, inflammation of the sinuses, and its symptoms, such as redness and swelling. The potential for ethmoid sinus infection to spread to the eye, causing blindness or optic neuritis, and frontal sinusitis to cause osteomyelitis or meningitis, is also covered. The paragraph emphasizes the rarity but importance of understanding these complications.

Keywords

💡Nasal Cavity

The nasal cavity is a central part of the respiratory system and is the main focus of the video. It is a hollow space within the bones of the face, lined with mucous membranes, and is responsible for the initial processing of air that enters the body. The script describes the nasal cavity as being bordered by the palate, with the hard palate at the front and the soft palate at the back, which is crucial for understanding its anatomical position and function.

💡Sinuses

Sinuses are air-filled cavities within the bones surrounding the nasal cavity. The video discusses the frontal and sphenoid sinuses specifically, which are two of the paranasal sinuses. These sinuses are important for the video's theme as they drain into the nasal cavity, and their inflammation, known as sinusitis, is a common condition affecting the respiratory system.

💡Pharynx

The pharynx, or throat, is a muscular tube that serves as a pathway for both food and air. The script divides it into three parts: the nasal pharynx, oral pharynx, and laryngopharynx. Understanding the pharynx is key to grasping the interconnectedness of the respiratory and digestive systems discussed in the video.

💡Epiglottis

The epiglottis is a flap of cartilage that prevents food and liquids from entering the windpipe (trachea) when swallowing. It is mentioned in the script as a gateway to the trachea, which connects the lungs, illustrating its role in the protection of the respiratory system.

💡Eustachian Tube

The Eustachian tube, also known as the pharyngotympanic tube, connects the middle ear to the back of the nasal pharynx. The video script explains that this tube allows for the equalization of air pressure on either side of the eardrum, which is crucial for hearing. It also highlights the clinical significance of the Eustachian tube in relation to upper respiratory tract infections potentially leading to middle ear infections.

💡Turbinate

Turbinates, also known as nasal conchae, are structures within the nasal cavity that help to warm and humidify the air that is inhaled. The script describes the inferior, middle, and superior turbinates, which are crucial for understanding the respiratory function of the nasal cavity.

💡Nasal Meatus

The nasal meatus are spaces located behind the turbinates where the sinuses drain into the nasal cavity. The video script mentions the superior, middle, and inferior meatus, which are important for understanding the drainage system of the sinuses and their connection to the nasal cavity.

💡Olfactory Segment

The olfactory segment is the part of the nasal cavity responsible for the sense of smell. It is lined with specialized cells that contain receptors for smell. The video script explains that these receptors make up the olfactory nerve, which carries signals related to smell to the brain.

💡Sella Turcica

The sella turcica is a saddle-shaped depression in the sphenoid bone that houses the pituitary gland. The script mentions it as an important anatomical landmark, illustrating its relevance in endocrinology and the study of the pituitary gland.

💡Rhinitis

Rhinitis, also known as coryza, is an inflammation of the mucous membrane of the nose. The video script explains that it can lead to sinusitis, which is inflammation of the sinuses. Understanding rhinitis is essential for grasping the progression of respiratory infections discussed in the video.

💡Maxillary Sinus

The maxillary sinus is one of the paranasal sinuses and is located within the maxilla, or upper jawbone. The script mentions that the maxillary sinus drains into the middle meatus, which is important for understanding the anatomy of the sinus drainage system.

Highlights

Introduction to the clinical anatomy of the nasal cavity and sinuses.

Explanation of the nasal cavity's structure and its borders, including the palate and pharynx.

Description of the epiglottis' role in connecting the trachea and its function during swallowing.

Division of the pharynx into three parts: nasal, oral, and laryngopharynx.

Location and function of the frontal and sphenoid sinuses.

Importance of the eustachian tube connecting the middle ear to the nasal cavity.

Function of the turbinates in warming and moisturizing air.

Role of the nasal meatus in draining sinuses.

Division of the nasal cavity into respiratory and olfactory segments.

Description of the olfactory segment's specialized cell type and its connection to the olfactory nerve.

Explanation of the sella turcica and its relation to the pituitary gland.

Discussion on rhinitis leading to sinusitis.

Recap of the nasal anatomy including the conchae and meatus.

Coronal section view of the nasal cavity and sinuses, including the maxillary sinus.

Pathophysiology of sinusitis and its potential to develop from rhinitis.

Complications of sinusitis, including the risk of blindness and meningitis.

Transcripts

hello in this video we're gonna talk

about the clinical anatomy of the nasal

cavity focusing on the sinuses let's

begin about cutting a cross section or

sagittal section of the nose and look at

the general structure and revise the

anatomy here is the nasal cavity the

nasal cavity is bordered in fear early

by the palate which consists of a hard

bony palate anteriorly and up and under

the back the soft palate which contains

no bone of course you have the oral

cavity here and the tongue here the

epiglottis is a gateway to the trachea

which connects the lungs the esophagus

is the root to the stomach

the epiglottis closes when we swallow

the throat I guess we can call the

pharynx and it can be divided into three

parts the very top is the nasal pharynx

which is in line with the nasal cavity

the middle is a oral pharynx which is in

line with the oral cavity and the bottom

is a laryngopharynx where we have the

larynx essentially your brain sits in

this cavity here at the top

surrounded by bone there's a small hole

in the front of our skull you can say

and this is actually a sinus and this is

called the frontal sinus sitting at the

posterior superior of the nasal cavity

is another sign is called the sphenoid

sinus of course we have actually more

sinuses than this but it's good to know

these two for now there are other

important structures within and

surrounding the nasal cavity let's take

a closer look again so here again we

have the nasal pharynx your hard palate

and your soft palate at the back of the

nasal cavity situated really within the

nasal pharynx is a small opening where

the eustachian tube also known as the

fairing go tympanic tube drains into

this tube literally connects your middle

ear to the nasal cavity so if we were to

draw the inner and middle ear quickly

this is your middle ear where you can

find your auditory ossicles about the

smallest bones in your body and this is

the eustachian tube also known as the

fairing

tympanic achoo the clinical significance

of this is that if you have an upper

respiratory tract infection this can

subsequently cause a middle ear

infection because there's this tube and

it's a gateway to the middle ear on each

side of the nasal cavity we also have

these things called turbinates which are

also known as in nasal conchae or Conca

for one there is the inferior concur

middle concur and superior concur the

function of the Conca conchae are to

help warm and more moisturize air that

is flowing through the nose now behind

each respected conchae you have the

nasal meatus some of the sinuses drain

into the meatus this really tells us

that the sinuses and the nasal cavity

are joined together as well so for

example the sphenoid sinus drains into

the superior meatus behind the superior

Conca the frontal sinus drains into the

middle meatus we can't look at the other

sinuses from this angle because it's too

hard now you can say the nasal cavity

has two segments it has the respiratory

segment which allows air to enter oxygen

and also air to go out so carbon dioxide

and the nasal cavity also has an

olfactory segment which is the area

which allows for smell essentially the

olfactory segment is lined with a

specialized cell type of

pseudostratified columnar epithelium and

these guys contain receptors for the

sense of smell this segment is located

in and beneath the mucosa of the roof of

each nasal cavity these receptors will

make up the olfactory nerve which is a

cranial nerve number one and this will

be carried back into the brain where

smell is perceived finally it's

important to mention the pouch here

which is the sella turcica which

translates to the turkish seat for

turkish saddle and this is essentially

the pituitary fossa with a pituitary

gland sits of course the gland doesn't

actually sit on it but it's rather

pretty

detected or encased by it rhinitis also

known as coryza is irritation and

inflammation of the mucosal membranes in

the nose because the nose and sinuses

are joined as we have learnt Ryan

itis can lead to sinusitis which is

inflammation of the sinuses let's recap

again the anatomy here is a superior

conquer middle conquer inferior conquer

and behind each conquer you have the

meatus

so here you have the superior meatus

middle meatus and inferior Mientus here

is your sphenoid sinus and frontal sinus

this is your nasal pharynx and remember

the faring go tympanic tube drained here

from the middle ear now this is one

angle of looking inside the nasal cavity

but let us cut a coronal section and

look at the nasal cavity and sinuses

from the front to orientate ourselves

this here is the orbit where the eyeball

sits and here is our teeth this is your

superior compa behind it the superior

meatus this is your middle conker behind

it the middle meatus inferior conker

behind it the inferior meters below the

orbit and lateral to the nasal cavity

are your maxillary sinus the maxillary

sinus like the frontal sinus drains into

the middle meatus

here are your frontal sinus which as we

talked about earlier sits essentially

above the orbit and they also drain into

the middle meatus the ethmoid sinus is

the fourth sinus we will talk about and

sits medial to the orbit the ethmoid

sinus drains into the superior and

middle meatus sinusitis or should we

call rhinosinusitis is inflammation of

the sinuses a feature of someone with

sinusitis is essentially redness or

erythema around where the sinuses lie

and so the frontal and maxillary sinus

may appear red and irritated the

pathophysiology of sinusitis as we have

learned can be secondary to rhinitis

rhinitis may spread to the sinuses

producing swelling and inflammation of

the sinus mucosa let's talk about

complications of sinusitis so flloyd

sinusitis is a particular concern

ethmoid sinus infection may break the

fragile medial wall of the orbit

allowing infection to spread to the eye

which can cause blindness or even optic

neuritis similarly frontal sinusitis can

also cause some complications and this

is shared with any sinuses sinusitis is

basically but it can cause osteomyelitis

for the frontal sinus if your infection

here the infection may or can invade the

brain causing meningitis and even form

an abscess in absolutely worst-case

scenarios of course these complications

are rare but it is good to know them

nonetheless

you