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The nasal cavity is a complex structure that is made up of a variety of different tissues, including bone, cartilage, mucous membranes, and blood vessels. These tissues work together to help filter and humidify the air that we breathe in through our nose, and to detect different smells and odors.

The nasal bones are two small bones that form the bridge of the nose, while the nasal cartilages are a series of flexible cartilage structures that help to support and shape the nostrils. Together, these structures help to protect the delicate tissues inside the nasal cavity from damage, and to regulate the flow of air through the nose.

The nasal cavity also contains several important structures that are involved in the sense of smell, including the olfactory epithelium, which is a specialized tissue that contains millions of tiny nerve cells called olfactory receptors. These receptors are responsible for detecting different odor molecules in the air, and sending signals to the brain to interpret the information.

In addition to its role in the sense of smell, the nose also plays an important role in the body’s respiratory system. The nasal cavity helps to filter out dust, dirt, and other pollutants from the air that we breathe, and it also helps to humidify and warm up the air before it enters the lungs.

Overall, the nose is a fascinating and complex organ that is critical to our sense of smell and our overall health and well-being. By understanding the anatomy and function of the nose, we can better appreciate the important role that it plays in our lives.

Anatomy of the External nose

The external nose is composed of several structures, including the nasal bones, nasal cartilage, and soft tissues such as skin, subcutaneous fat, and muscles. The nasal bones form the upper part of the nasal pyramid, while the lower part is composed of the nasal cartilages.

The nasal bones are two small, rectangular-shaped bones that make up the upper part of the bridge of the nose. They are attached to the frontal bone of the skull at the top and the nasal cartilages at the bottom. The shape and size of the nasal bones can vary widely among individuals and can affect the appearance and function of the nose.

The nasal cartilages are a series of flexible cartilage structures that make up the lower part of the nasal pyramid. They are responsible for giving the nose its shape and support, and are attached to the nasal bones, the septum, and the upper lateral cartilages.

In addition to the bones and cartilage, the external nose is also composed of several layers of skin, subcutaneous fat, and muscles. The muscles of the nose are responsible for controlling the movement of the nostrils and the size of the nasal passages.

Overall, the anatomy of the external nose is a complex and intricate structure that plays an important role in our appearance, breathing, and sense of smell. Understanding the various components of the nose can help us better appreciate its function and importance in our daily lives.

Osteocartilaginous Framework Bony Part

The osteocartilaginous framework of the nose refers to the combination of bony and cartilaginous structures that make up the external nose. As mentioned, the upper third of the external nose is bony and the lower two-thirds are cartilaginous.

The bony part of the nose is composed of two nasal bones that meet at the midline and rest on the upper part of the nasal process of the frontal bones. These bones are also held between the frontal processes of the maxillae, which are the two bones that make up the upper jaw. The nasal bones help to provide support and structure to the upper part of the external nose.

The cartilaginous part of the nose is made up of several flexible cartilage structures that give the nose its shape and support. These cartilages include the lower lateral cartilages, the upper lateral cartilages, and the septal cartilage. The lower lateral cartilages form the lower part of the external nose, while the upper lateral cartilages and septal cartilage are located in the middle and upper part of the nose.

Overall, the osteocartilaginous framework of the nose is a complex and important structure that helps to provide support and shape to the external nose.

The cartilaginous part of the nose is an important component of the osteocartilaginous framework of the nose. It is composed of several flexible cartilage structures that help to give the nose its shape and support.

1. The upper lateral cartilages are located in the upper part of the nose and extend from under the surface of the nasal bones above, to the alar cartilages below. They fuse with the upper border of the septal cartilage in the midline anteriorly. The lower free edge of the upper lateral cartilage is visible intranasally as the limen vestibule, nasal valve, or limen nasi on each side. The upper lateral cartilages play an important role in supporting the nasal dorsum and helping to maintain the shape of the nose.
2. The lower lateral cartilages, also known as the alar cartilages, are U-shaped and are located in the lower part of the nose. Each alar cartilage has a lateral crus that forms the ala and a medial crus that runs in the columella. The lateral crus overlaps the lower edge of the upper lateral cartilage on each side. The lower lateral cartilages help to give the nose its shape and support the nasal tip.
3. The lesser alar or sesamoid cartilages are two or more in number and are located above and lateral to the alar cartilages. These cartilages are connected to the adjoining bones by the perichondrium and periosteum.
4. The septal cartilage is located in the middle of the nose and helps to separate the two nostrils. Its anterosuperior border runs from the bottom of the nasal bones to the nasal tip, and it abides by the dorsum of the cartilaginous part of the nose. The septal cartilage is an important structure that helps to support the nasal dorsum and maintain the shape of the nose.

In summary, the cartilaginous part of the nose is composed of several flexible cartilage structures that work together to give the nose its shape and support.

Nasal Musculature

The muscles of the nose are responsible for movements of the nasal tip, ala, and the overlying skin. They are attached to the osteocartilaginous framework of the nose and help to control the shape and position of the nose.

1. The procerus muscle is a small muscle located between the eyebrows that helps to bring the skin of the forehead and nose downwards, creating wrinkles on the bridge of the nose.
2. The nasalis muscle is divided into two parts: the transverse part and the alar part. The transverse part helps to compress the nostrils, while the alar part helps to flare the nostrils.
3. The levator labii superioris alaeque nasi muscle is responsible for elevating the upper lip and dilating the nostrils.
4. The anterior dilator naris muscle is located in the anterior part of the nose and helps to dilate the nostrils.
5. The depressor septi muscle is located in the septum of the nose and helps to depress the nasal tip.

All of these muscles work together to control the shape and position of the nose. By understanding the nasal musculature, we can better appreciate the complex movements of the nose and the importance of each muscle in creating the final appearance of the nose.

Nasal Skin

The skin covering the nose is an important aspect of its overall appearance. The skin over the nasal bones and upper lateral cartilages is thin and mobile, which allows for changes in the shape and position of the nose. In contrast, the skin covering the alar cartilages is thicker and more adherent, and contains many sebaceous glands.

When these sebaceous glands become enlarged or hypertrophied, they can give rise to a condition called rhinophyma. Rhinophyma is a lobulated tumor that typically affects the tip of the nose and can cause significant disfigurement. It is often associated with rosacea, a chronic skin condition characterized by redness and flushing of the face.

The skin over the nose is also important for surgical procedures, as it must be carefully repositioned and sutured to achieve the desired result. Surgeons may use techniques such as skin grafts or tissue expanders to reconstruct the skin after trauma or surgery.

Anatomy of the Internal Nose

The internal nose plays an important role in the respiratory system, as it serves as a passage for air to enter the lungs. The internal nose is divided into two nasal cavities by the nasal septum, which is made up of bone and cartilage. The nasal septum runs from the base of the nose to the skull, and separates the right and left nasal cavities.

Each nasal cavity is further divided into several passages by bony projections called turbinates or conchae. These turbinates increase the surface area of the nasal cavity, allowing for more efficient warming, humidifying, and filtering of the air as it passes through the nose.

The front part of each nasal cavity, known as the vestibule, is lined with skin and contains hairs that help to filter out larger particles. The back part of the nasal cavity, known as the nasal cavity proper, is lined with a mucous membrane that helps to moisten and warm the air as it passes through.

The nasal cavity also contains numerous blood vessels and nerves that help to regulate the flow of air and control the sense of smell. Additionally, the mucous membrane of the nasal cavity produces mucus, which helps to trap and remove foreign particles, bacteria, and viruses from the air before they can enter the lungs.

Vestibule of Nose

The vestibule of the nose plays an important role in the overall function of the nasal cavity. The vibrissae, or nasal hairs, located in the vestibule act as a first line of defense against harmful particles and microorganisms in the air we breathe. They trap and filter out large particles such as dust, pollen, and bacteria before they can enter deeper into the nasal cavity.

In addition to the vibrissae, the sebaceous glands in the vestibule secrete oil to help keep the skin moist and prevent drying out. The skin in the vestibule is also rich in blood vessels and nerve endings, which make it highly sensitive to touch and temperature changes.

The limen nasi, also known as the nasal valve, is a narrow passage located between the upper lateral cartilage and the septum that acts as a bottleneck to regulate the airflow and resistance on inspiration. This area has the least cross-sectional area of the nose and can be a site of obstruction in some individuals, leading to difficulty breathing through the nose.

The vestibule of the nose can also be affected by various conditions such as nasal vestibulitis, which is an inflammation of the skin in the vestibule, and nasal vestibular stenosis, which is a narrowing of the nasal valve area. Proper hygiene and care of the vestibule, such as regular cleaning and moisturizing, can help prevent these conditions from occurring.

Nasal Valve:

The nasal valve is an important area of the nasal cavity as it plays a crucial role in regulating airflow and resistance during inspiration. It is the narrowest part of the nasal airway and its cross-sectional area is the least among all parts of the nasal cavity. This area is divided into the internal and external nasal valve, with the internal valve being the narrowest and most significant.

The internal nasal valve is formed by the inferior border of the upper lateral cartilage, the anterior edge of the inferior turbinate, and the nasal septum. The external nasal valve is formed by the nostril rim, the nasal floor, and the lateral nasal wall. Any obstruction or narrowing in these areas can lead to nasal airflow problems, such as nasal congestion and difficulty breathing.

In addition to the structural components, the nasal valve is also influenced by the nasal mucosa, which can swell due to allergies or inflammation, further contributing to airflow resistance. Hence, any underlying nasal condition or pathology that affects the nasal valve can lead to nasal obstruction and impaired nasal function.

It is important to note that the anatomy and function of the nasal valve can vary among individuals, and certain factors such as age, gender, and nasal anatomy can also influence nasal valve function.

 Nasal cavity proper

Each nasal cavity has a

1. Lateral wall
2. Medium wall
3. Roof
4. Floor.

Lateral Nasal Wall

The lateral nasal wall is an important component of the nasal cavity. It consists of three turbinates, which are also known as nasal conchae. These turbinates are thin, scroll-like bony structures that are covered by mucous membrane. The turbinates help to increase the surface area of the nasal cavity, which facilitates the warming, humidification, and filtration of inhaled air.

The three turbinates are named the superior, middle, and inferior turbinates. The superior and middle turbinates arise from the ethmoid bone, while the inferior turbinate arises from the maxillary bone. In some people, a fourth turbinate, known as the supreme turbinate or supreme concha, may also be present.

The spaces below the turbinates are known as meatuses. The superior meatus is located above the superior turbinate, the middle meatus is located between the middle and inferior turbinates, and the inferior meatus is located below the inferior turbinate. These meatuses are important for the drainage of the paranasal sinuses and the tear ducts.

The lateral nasal wall also contains the openings of the paranasal sinuses, which are air-filled spaces within the bones of the face that communicate with the nasal cavity. The sinuses include the frontal sinuses, ethmoid sinuses, sphenoid sinuses, and maxillary sinuses. The ostia or openings of the sinuses are located in the lateral wall of the nasal cavity, and they allow for the drainage of mucus from the sinuses into the nasal cavity.

Inferior turbinate:

The inferior turbinate is not a separate bone, but rather a scroll-like structure made of bone covered by a mucous membrane. It is the largest of the three nasal turbinates and it extends horizontally along the lower lateral wall of the nasal cavity, dividing it into the inferior meatus below and the middle meatus above.

The inferior meatus is the narrowest of the nasal meatuses and it is located beneath the inferior turbinate. It is an important pathway for the drainage of tears through the nasolacrimal duct, which empties into the inferior meatus at a point just below the inferior turbinate. The terminal end of the nasolacrimal duct is guarded by a mucosal fold called the valve of Hasner, which prevents the reflux of air from the nose into the lacrimal sac.

Middle turbinate:

The middle turbinate is a complex structure that plays a crucial role in the anatomy of the nasal cavity. It is an ethmoturbinal, which is a bony structure that is part of the ethmoid bone. The middle turbinate is attached to the lateral wall by a bony lamella called the ground or basal lamella. However, its attachment is not straight but rather in an S-shaped manner, which is important for its function in the nasal cavity.

The middle turbinate can be divided into three parts: anterior, middle, and posterior. In the anterior third, it lies in the sagittal plane and is attached to the lateral edge of the cribriform plate. In the middle third, it belongs in the frontal plane and is allocated to the lamina papyracea, while in its posterior third, it runs horizontally and forms the roof of the middle meatus and is appointed to the lamina papyracea and medial wall of the maxillary sinus.

The middle turbinate plays an important role in the drainage of the paranasal sinuses. The Ostia of various sinuses draining anterior to the basal lamella form the anterior group of paranasal sinuses, while those which open posterior and superior to it form the posterior group. The middle turbinate acts as a barrier to the anterior group of sinuses, helping to direct their drainage into the middle meatus. This drainage is crucial for maintaining the health of the sinuses and preventing sinusitis.

In addition to its role in sinus drainage, the middle turbinate also helps to regulate airflow and humidity in the nasal cavity. It acts as a filter, removing dust and other particles from the air as it passes through the nasal cavity. It also helps to warm and humidify the air, which is important for protecting the sensitive mucous membranes that line the nasal cavity.

Middle Meatus

The middle meatus is a critical structure in the anatomy of the nasal cavity, as it contains several important structures that are crucial for endoscopic surgery of the sinuses. One of the most significant structures in the middle meatus is the uncinate process, which is a hook-like structure that runs in an anterosuperior to the posteroinferior direction.

The posterosuperior border of the uncinate process is sharp and runs parallel to the anterior border of the bulla ethmoidal, creating a narrow gap called the hiatus semilunaris (inferior). This gap is a two-dimensional space of 1-2mm width and is essential for the drainage of the frontal, maxillary, and anterior ethmoid sinuses.

The anteroinferior circumference of the uncinate process is attached to the lateral wall, while the posteroinferior borderline is attached to the inferior turbinate, dividing the membranous part of the lower-middle meatus into anterior and posterior fontanelles. The fontanelle area is devoid of bone and consists of membrane only, leading into the maxillary sinus when perforated. This area is important in endoscopic surgery of the sinuses, as it provides access to the maxillary sinus for the drainage of mucus and other fluids.

The upper attachment of the uncinate process shows great variation and may be inserted into the lateral nasal wall, upwards into the base of the skull, or medially into the middle turbinate. This variation accounts for the differences in the drainage of the frontal sinus and can affect the success of endoscopic surgery.

The space bounded medially by the uncinate process and frontal process of the maxilla and sometimes the lacrimal bone, and laterally by the lamina papyracea, is called the infundibulum. The infundibulum is a critical area for the drainage of the maxillary sinus and is an important target for endoscopic surgery of the sinuses.

Bulla ethmoidal

The bulla ethmoidal is an important structure located in the ethmoid bone of the nasal cavity. It is situated behind the uncinate process, and its anterior surface forms the posterior boundary of the hiatus semilunaris.

The bulla ethmoidal can vary in shape and size depending on pneumatization. It can either be a pneumatized cell or a solid bony prominence. In some cases, it may extend superiorly to the skull base and posteriorly to fuse with the ground lamella. When there is a space above or behind the bulla, it is called the suprabulla or retrobulbar recess, respectively.

The suprabullar and retrobulbar recesses together form the lateral sinus, also known as the sinus lateral of Grunwald. The lateral sinus is surrounded superiorly by the skull base, laterally by the lamina papyracea, and medially by the middle turbinate.

The bulla ethmoidal also communicates with the skull base via a cleft-like opening that leads into the middle meatus. This opening is called the hiatus semilunaris superior in contrast to the hiatus semilunaris inferior that was referred to before. The hiatus semilunaris superior is important in the drainage of the anterior ethmoid sinus, and it is a critical area in endoscopic surgery of the sinuses.

Atrium of the middle meatus:

It is a shallow depression lying in front of the middle turbinate and above the nasal vestibule. you must learn detail about the meatus in the anatomy of the nose.

Agger nasal:

The agger nasal, also known as the agger nasi or nasal spur, is an important anatomical structure in the nasal cavity. It is located just anterior to the attachment of the middle turbinate, and when present, it may contain air cells known as the agger nasi cells. These cells communicate with the frontal recess, which is a narrow passage that connects the frontal sinus to the nasal cavity.

In some individuals, the agger nasi cell may be broadened or enlarged, which can lead to mechanical obstruction of the frontal recess and impede the proper drainage of the frontal sinus. This can cause symptoms such as facial pain and pressure, nasal congestion, and recurrent sinus infections.

Another common anatomical variation in the nasal cavity is the presence of a concha bullosa, which is an enlarged and ballooned-out middle turbinate that results from pneumatization. This can also lead to obstruction of the frontal recess and interfere with the proper drainage of the frontal sinus.

The Haller cell is another important anatomical variation that can affect the drainage of the maxillary sinus. These air cells are situated in the roof of the maxillary sinus and can be pneumatized from either the anterior or posterior ethmoid cells. When the Haller cells are enlarged, they can encroach on the ethmoid infundibulum, which is the narrow passage that connects the maxillary sinus to the nasal cavity, and cause obstruction of the sinus drainage. This can result in symptoms such as pain and pressure in the cheek area, dental pain, and recurrent sinus infections.

Superior Turbinate

The superior turbinate is an important structure in the anatomy of the nasal cavity. It is a shelf-like bony projection that extends horizontally from the lateral wall of the nose. The superior turbinate has a variable shape and size and is typically larger than the middle and inferior turbinate. It is covered by a thin layer of mucous membrane that is rich in blood vessels and nerves.

The superior turbinate is located posterior and superior to the middle turbinate, and it serves to divide the nasal cavity into the superior meatus and the sphenoethmoidal recess. The superior meatus is a narrow space located below the superior turbinate and above the middle turbinate. It is an important site for the drainage of the posterior ethmoid air cells.

The posterior ethmoid air cells are a group of air-filled spaces located in the posterior part of the ethmoid bone. They are variable in number and can range from 1 to 5 cells. These cells drain into the superior meatus via small openings in the lateral nasal wall.

The superior turbinate is also an important landmark for identifying the ostium of the sphenoid sinus. The ostium of the sphenoid sinus is located in the sphenoethmoidal recess, which is located medial to the superior turbinate. The sphenoid sinus is a large, paired, air-filled cavity located in the sphenoid bone. The sphenoid sinus is an important structure in the skull base and is surrounded by vital structures such as the optic nerve and the carotid artery.

Superior Meatus

The superior meatus is one of the three meatuses located in the nasal cavity, and it is situated below the superior turbinate. This meatus is relatively smaller than the middle meatus and inferior meatus. The posterior ethmoid cells, which are part of the ethmoidal sinuses, open into the superior meatus. The number of posterior ethmoid cells may vary from one to five, and they may have a significant anatomical variation. These cells are important in the context of endoscopic sinus surgery as their pneumatization and variations can sometimes cause obstruction or inflammation in the surrounding structures, leading to clinical symptoms such as nasal obstruction, facial pain, and headache.

Onodi Cell

The Onodi cell is a type of posterior ethmoidal cell that is located adjacent to or superior to the sphenoid sinus. It is also known as the “sphenoethmoidal” or “sphenoidal” cell. The size and shape of the Onodi cell can vary considerably among individuals. It may extend posteriorly along the lateral wall of the sphenoid sinus or superiorly for a distance of up to 1.5 cm from the anterior surface of the sphenoid.

The Onodi cell is important in endoscopic sinus surgery as it is located in close proximity to the optic nerve, which carries visual information from the eyes to the brain. The lateral wall of the Onodi cell may also be adjacent to the internal carotid artery, which supplies blood to the brain. Therefore, any surgical manipulation of the Onodi cell should be approached with caution to avoid potential damage to these important structures.

The presence and size of Onodi cells can also impact the surgical management of sphenoid sinus disease. In some cases, the Onodi cell may be involved in the drainage pathway of the sphenoid sinus, and its removal may be necessary to achieve adequate drainage and prevent recurrence of disease.

Sphenoethmoidal recess

The sphenoethmoidal recess is a small area located above the superior turbinate, in the posterior part of the nasal cavity. It is a passageway that connects the sphenoid sinus with the nasal cavity. The sphenoid sinus is one of the paranasal sinuses located in the skull and is situated behind the ethmoid sinuses. The sphenoethmoidal recess is important in endoscopic sinus surgery as it provides access to the sphenoid sinus for treatment of sinus disorders or for sampling of sinus tissue for laboratory analysis.

Supreme turbinate:

The supreme turbinate, also known as the supreme nasal turbinate, is a small and variable structure located above the superior turbinate in the nasal cavity. It is sometimes absent in some individuals. It has a narrow meatus, called the supreme meatus, located beneath it. The supreme meatus is the smallest of the meati in the nasal cavity.

The sphenoid sinus, which is located in the body of the sphenoid bone at the back of the nasal cavity, opens into the sphenoid-ethmoidal recess. The ostium of the sphenoid sinus is situated in this recess, which is located medial to the superior or supreme turbinate. The supreme turbinate can be visualized endoscopically as a small and elongated structure about 1cm above the upper margin of the posterior choana, close to the posterior border of the nasal septum.

In some cases, the supreme turbinate may be the only structure separating the sphenoid sinus from the nasal cavity, and therefore, it is an important landmark in endoscopic sinus surgery. Its location should be carefully noted during procedures to avoid damaging the adjacent structures, such as the optic nerve or the carotid artery.

Medial Wall

The nasal septum is a bony and cartilaginous structure that divides the nasal cavity into two halves and forms the medial wall of the nasal cavity. The septum is composed of the perpendicular plate of the ethmoid bone, the vomer bone, and the quadrangular cartilage. The perpendicular plate of the ethmoid bone forms the superior portion of the septum, while the vomer bone forms the inferior and posterior portions. The quadrangular cartilage forms the anterior and inferior portion of the septum and is flexible, allowing for movement during breathing. The nasal septum plays an important role in regulating airflow and maintaining nasal symmetry.

Roof:

The roof of the nasal cavity is formed by multiple bones, including the nasal bones, which form the anterior part of the roof, and the body of the sphenoid bone, which forms the posterior part of the roof. The middle part of the roof is formed by the cribriform plate of the ethmoid bone, which is a thin, sieve-like structure that separates the nasal cavity from the cranial cavity.

The olfactory nerves, which are responsible for the sense of smell, pass through tiny openings in the cribriform plate to reach the olfactory epithelium in the upper part of the nasal cavity. This is why damage to the cribriform plate can cause anosmia (loss of sense of smell).

Floor

The floor of the nasal cavity is located below the medial wall and separates the nasal cavity from the oral cavity. The anterior three-fourths of the floor is formed by the palatine process of the maxilla, which is a horizontal projection of the maxillary bone that forms the hard palate. The posterior one-fourth of the floor is formed by the horizontal part of the palatine bone, which extends from the posterior edge of the hard palate to the posterior wall of the nasopharynx.

The floor of the nasal cavity is not a flat surface, but rather has several elevations and depressions. The elevations include the medial and lateral nasal prominences, which form the borders of the nasal vestibule, and the inferior nasal conchae, which are scroll-like bones that protrude from the lateral wall of the nasal cavity. The depressions include the inferior meatus, which is a groove below the inferior nasal concha that receives the nasolacrimal duct, and the sphenoethmoidal recess, which is a space above the superior nasal concha that receives the opening of the sphenoid sinus.

Kiesselbach plexus

The Kiesselbach plexus, or Little’s area, is a complex network of arteries and veins located in the anterior region of the nasal septum. This region is critical for proper nasal function, as it regulates the perfusion and drainage of the nasal mucosa.

The Kiesselbach plexus is formed by the convergence of four arteries:

1. Anterior ethmoidal
2. Sphenopalatine
3. Greater palatine
4. Superior labial arteries.

The anastomosis of these arteries makes this area particularly vulnerable to damage, which can result in epistaxis or nasal bleeding.

Epistaxis is a common medical condition that can occur spontaneously or from minor trauma to the nasal mucosa. It is estimated that up to 60% of the general population will experience some form of nasal bleeding at least once in their lifetime. However, the incidence is higher in certain populations such as elderly people, patients with hypertension, and those with underlying coagulation disorders.

The management of epistaxis requires a systematic approach, starting with basic first aid measures such as pinching the nose and applying ice to the nasal bridge. If bleeding persists, further interventions may be necessary, including the use of topical or systemic vasoconstrictors, nasal packing, cauterization, or even surgical intervention.

It is important to note that the treatment of epistaxis depends on the severity and underlying cause of the bleeding. In some cases, epistaxis may be a symptom of an underlying condition that requires further investigation and management. Therefore, it is crucial to seek medical attention if nasal bleeding is severe or recurrent.

In conclusion, the Kiesselbach plexus is a critical region in the nasal cavity, and damage to the vessels in this area can result in epistaxis. Proper management of nasal bleeding requires a stepwise approach, starting with basic first aid measures and progressing to more aggressive interventions if necessary. It is essential to seek medical attention if nasal bleeding is severe or recurrent.

The lining membrane of the internal nose

The nose is a complex structure composed of different regions, each with a specific function. The lining membrane of the internal nose consists of three regions: the vestibule, the olfactory region, and the respiratory region.

The vestibule is the most anterior part of the nasal cavity and is lined by skin that contains hair, hair follicles, and sebaceous glands. This region serves to filter and humidify the air that enters the nose.

The olfactory region is located in the upper one-third of the lateral wall, corresponding part of the nasal septum, and the roof of the nasal cavity. In this region, the mucous membrane is paler in color and contains specialized olfactory receptors responsible for detecting and interpreting different odors.

The respiratory region is located in the lower two-thirds of the nasal cavity and is responsible for filtering, warming, and humidifying the air that we breathe. The mucous membrane in this region is highly vascular and contains erectile tissue. It is lined by pseudostratified ciliated columnar epithelium with numerous goblet cells that secrete mucus to trap dust, dirt, and other foreign particles. The submucosa layer of the mucous membrane contains serous, mucous, and both serous and mucous secreting glands whose ducts open on the surface of the mucosa.

The lining membrane of the nose is an integral part of the nasal anatomy and plays a crucial role in the respiratory and olfactory functions of the nose. Understanding the different regions and structures of the nasal lining membrane is essential for diagnosing and treating various nasal disorders.

Nasal conchae

Nasal conchae are crucial structures that play a significant role in respiratory function. They are thin, scroll-shaped bony elements located in the upper chambers of the nasal cavities and are also known as turbinate or turbinal bones.

There are three pairs of nasal conchae: the superior, middle, and inferior conchae. The superior and middle conchae are part of the ethmoid bone, while the inferior conchae are separate bones.

The nasal conchae serve to increase the surface area of the nasal cavity, which helps to filter, warm, and humidify the air that passes through the nose. As air enters the nasal cavity, it is directed over the nasal conchae, which cause turbulence and slow down the airflow. This allows for efficient filtering of dust, dirt, and other foreign particles present in the air.

Additionally, the nasal conchae are covered by a mucous membrane that contains numerous blood vessels. As air passes over this membrane, it is warmed and humidified, which helps to protect the lungs from cold, dry air that can cause irritation and inflammation.

Problems with the nasal conchae can lead to various respiratory disorders, such as nasal congestion, chronic sinusitis, and sleep apnea. In some cases, surgery may be necessary to correct these issues and restore proper respiratory function.

Nerve supply

When you start reading the anatomy of the nose, the Nerve supply is one of the important contributions to the anatomy of the nose. Here begins the nerve supply of the nose.

Olfactory Nerves:

The olfactory nerves are responsible for our sense of smell and are crucial for detecting different odors in the environment. These nerves are made up of central filaments of the olfactory cells and are arranged into 12-20 nerves, which travel through small openings in the cribriform plate of the ethmoid bone and end in the olfactory bulb.

It is interesting to note that the olfactory nerves can carry sheaths of dura, arachnoid, and pia with them as they travel through the cribriform plate into the nasal cavity. This makes the olfactory nerves more vulnerable to injury, and any damage to these nerves can lead to significant health complications.

One potential complication of olfactory nerve injury is the development of cerebrospinal fluid (CSF) rhinorrhoea. This occurs when a tear or a hole in the cribriform plate allows CSF to leak into the nasal cavity. CSF rhinorrhoea can cause a persistent runny nose, headache, and increased risk of infection, as well as a loss of the sense of smell.

Injury to the olfactory nerves can also lead to meningitis, a serious infection that affects the lining of the brain and spinal cord. This is because the nerves travel through the cribriform plate, which is in close proximity to the brain and its protective coverings.

In summary, the olfactory nerves play a crucial role in our sense of smell and are vulnerable to injury due to their unique structure and location. Damage to these nerves can lead to significant health complications, including CSF rhinorrhoea and meningitis. It is essential to take appropriate measures to protect these nerves and seek medical attention if any injury or damage is suspected.

NERVES OF COMMON SENSATION:

They are:

1. The anterior ethmoidal nerve.
2. Branches of the sphenopalatine ganglion.
3. Branches of the infraorbital nerve. They source the vestibule of the nose both on its medial and lateral side.

The nasal cavity is a complex structure that serves several important functions, including filtering, humidifying, and warming the air we breathe. The nerves of common sensation in the nasal cavity play a critical role in these functions by providing sensory information related to touch, pain, temperature, and pressure. In addition to the nerves mentioned above, there are several other nerves that are involved in the sensation of the nasal cavity.

The ophthalmic division of the trigeminal nerve is one such nerve. It supplies the skin of the nasal bridge and the upper part of the nasal septum, as well as the lacrimal gland and conjunctiva. This nerve can be blocked by injecting a local anesthetic into the supraorbital foramen, which is located at the superior margin of the orbit.

The maxillary division of the trigeminal nerve also supplies the nasal cavity, including the nasal floor and lateral wall. This nerve can be blocked by injecting a local anesthetic into the infraorbital foramen, which is located on the maxillary bone just below the infraorbital ridge.

In addition to providing sensory information, the nerves of common sensation in the nasal cavity also play a role in regulating blood flow and mucus secretion. For example, the sphenopalatine ganglion is involved in the regulation of blood flow to the nasal mucosa and the secretion of mucus by the glands in the nasal cavity.

Understanding the anatomy and function of the nerves of common sensation in the nasal cavity is essential for the diagnosis and treatment of nasal disorders. For example, nasal pain and headache can be caused by inflammation or irritation of these nerves, and blocking these nerves can provide significant relief. Additionally, nasal surgery often involves blocking these nerves to minimize pain and discomfort during the procedure.

AUTONOMIC NERVES.

The autonomic nerves play an important role in the regulation of nasal function. The parasympathetic and sympathetic nerves are the two main divisions of the autonomic nervous system that supply the nasal cavity.

Parasympathetic nerve fibers are responsible for controlling nasal gland secretion and promoting vasodilation of the blood vessels in the nasal cavity. These fibers originate from the greater superficial petrosal nerve and travel through the nerve of the pterygoid canal (vidian nerve) before reaching the sphenopalatine ganglion. At the ganglion, they synapse with other neurons before continuing to the nasal cavity. The parasympathetic fibers also regulate mucus production in the nasal cavity, which is important for maintaining the health and function of the nasal passages.

Sympathetic nerve fibers, on the other hand, are responsible for regulating vasoconstriction of the blood vessels in the nasal cavity. These fibers originate from the upper two thoracic segments of the spinal cord and pass through the superior cervical ganglion before traveling in the deep petrosal nerve. They then join with the parasympathetic fibers of the greater petrosal nerve to form the nerve of the pterygoid canal (vidian nerve). From there, they regulate blood flow to the nasal cavity and also play a role in the regulation of nasal secretions.

Imbalances in the autonomic nerves can lead to various nasal disorders. For example, an overactive parasympathetic nervous system can lead to excessive mucus production, while an overactive sympathetic nervous system can cause nasal congestion and decreased blood flow to the nasal cavity. Understanding the role of the autonomic nerves in nasal function is essential for the diagnosis and treatment of nasal disorders.

Sympathetic nerve fibers also innervate the nasal cavity, and they do not relay in the sphenopalatine ganglion like the parasympathetic fibers do. Their main function is to regulate vasoconstriction of the blood vessels in the nasal cavity, which helps control blood flow and reduce nasal secretions. Excessive rhinorrhea in cases of vasomotor and allergic rhinitis can be controlled by a section of the vidian nerve, which disrupts the sympathetic nerve supply to the nasal cavity.

Regarding the nerve supply of the nose, there are several other nerves that play a role in nasal function. The trigeminal nerve (CN V) is responsible for providing general sensation to the nasal cavity, including touch, temperature, and pain. It has three main branches that supply different regions of the nasal cavity, including the ophthalmic, maxillary, and mandibular branches. The ophthalmic branch supplies the anterior portion of the nasal cavity, while the maxillary branch supplies the posterior portion. The mandibular branch supplies the nasal septum and floor of the nasal cavity.

The olfactory nerve (CN I) is responsible for providing the sense of smell. It is located in the olfactory epithelium in the upper part of the nasal cavity and is stimulated by the presence of odor molecules. Damage to the olfactory nerve can result in a loss of sense of smell, known as anosmia.

Blood supply

The internal carotid artery supplies the anterior part of the nasal septum through the anterior ethmoidal artery, which also supplies the frontal sinus and ethmoidal air cells. The internal carotid artery also supplies the posterior part of the nasal septum through the sphenopalatine artery, which also supplies the posterior ethmoidal air cells, sphenoid sinus, and lateral wall of the nasal cavity.

The external carotid artery supplies the majority of the nasal cavity, including the lateral wall and vestibule of the nose, through its branches. The facial artery supplies the vestibule of the nose and the nasal alae. The superior labial artery, a branch of the facial artery, supplies the septum and nasal tip. The maxillary artery, another branch of the external carotid artery, supplies the lateral wall of the nasal cavity and the posterior portion of the nasal septum.

The blood supply of the nose is important for several reasons. It provides oxygen and nutrients to the nasal tissues and helps regulate temperature and humidity in the nasal cavity. Understanding the blood supply of the nose is also important for surgical procedures, as it can help prevent excessive bleeding and complications during surgery.

Lymphatic Drainage

The lymphatic drainage of the nasal cavity plays a crucial role in the immune response and clearance of pathogens. The external nose and anterior part of the nasal cavity drain into submandibular lymph nodes, which are located beneath the mandible in the neck region. The submandibular nodes receive lymphatic vessels that originate from the lateral nasal wall, nasal septum, and the nasal vestibule.

On the other hand, the remaining portions of the nasal cavity drain into the upper jugular nodes, which are situated along the internal jugular vein in the neck region. The upper jugular nodes receive lymphatic vessels that originate from the posterior nasal cavity, including the nasopharynx, posterior nasal septum, and paranasal sinuses. The retropharyngeal nodes also receive lymphatic vessels from the posterior nasal cavity and drain into the upper jugular nodes.

It is worth noting that the lymphatics of the upper part of the nasal cavity have a unique pathway. These lymphatics communicate with the subarachnoid space along the olfactory nerves, which are responsible for the sense of smell. This pathway allows for the direct exchange of immune cells and pathogens between the nasal cavity and the central nervous system. Therefore, any infection or inflammation in the nasal cavity can potentially spread to the brain through this pathway, highlighting the importance of maintaining proper nasal hygiene and seeking medical attention when necessary.

Types of noses

Here are eight types of noses: 

1. Types of Noses: the Nubian nose
2. The greek nose
3. The hook nose
4. The arched nose
5. The button nose
6. The straight nose
7. The concave nose
8. Types of Noses: the crooked nose.

Conclusion

In conclusion, the nose is a complex and essential organ of the human body that serves both respiratory and olfactory functions. Understanding the anatomy of the nose, including its external meatus, external nostrils, septum, nasal passage, and sinuses, is crucial for diagnosing and managing various nasal disorders. The nasal bones and the cilia-lined mucous membranes play vital roles in filtering the air that we breathe, while the sinuses help regulate the temperature and humidity of the air. Proper nasal hygiene and medical attention are necessary to maintain a healthy nose and prevent potential complications. Overall, the anatomy of the nose is fascinating and highlights the intricate interconnections of various body systems.