NASAL CAVITY AND PARANASAL

SINUSES

NASAL CAVITY AND PARANASAL

SINUSES

Dr. Vohra

THE NOSETHE NOSE

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THE NOSETHE NOSE• The external nose

has a free tip (apex) and a root (bridge).

• The external orifices are the two nostrils (nares).

• Each nostril is bounded medially by the nasal septum.

• The external nose has a free tip (apex) and a root (bridge).

• The external orifices are the two nostrils (nares).

• Each nostril is bounded medially by the nasal septum.

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THE NOSETHE NOSE

The nostrils are bounded laterally by the alla.

The nostrils are bounded laterally by the alla.

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NOSENOSE

The framework of the nose is made:

• Above by :– The nasal bones;– The frontal

processes of the maxillae;

– The nasal part of the frontal bone

• Below by hyaline carilages:

– Upper nasal cartilages

– Lower nasal cartilages

– Septal catilage

The framework of the nose is made:

• Above by :– The nasal bones;– The frontal

processes of the maxillae;

– The nasal part of the frontal bone

• Below by hyaline carilages:

– Upper nasal cartilages

– Lower nasal cartilages

– Septal catilage

Blood Supply of the External NoseThe skin of the external nose is supplied by branches of the ophthalmic and the maxillary arteries.

The skin of the ala and the lower part of the septum are supplied by branches from the facial artery.

Nerve Supply of the External NoseThe infratrochlear and external nasal branches of the ophthalmic nerve (CN V) and the infraorbital branch of the maxillary nerve

NASAL CAVITYNASAL CAVITY

BOUNDARIESNERVE SUPPLYBLOOD SUPPLY

LYMPH DRAINAGE

BOUNDARIESNERVE SUPPLYBLOOD SUPPLY

LYMPH DRAINAGE

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BOUNDARIESBOUNDARIES

• From the nostrils in front

• to the choanae behind

• Divided into right and left half by the nasal septum

• Each half has:– Floor– Roof– Lateral wall– Medial wall

• From the nostrils in front

• to the choanae behind

• Divided into right and left half by the nasal septum

• Each half has:– Floor– Roof– Lateral wall– Medial wall

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Boundaries of the Nasal CavityBoundaries of the Nasal Cavity

• The floor (this is the upper surface of the hard palate) is made from:– The palatine process of the maxilla and– The horizontal process of the palatine bone

• The roof is narrow and it is formed, from behind forward, by:– The body of the sphenoid– The cribriform plate of the ethmoid– The frontal bone– The nasal bone– The nasal cartilages

• The floor (this is the upper surface of the hard palate) is made from:– The palatine process of the maxilla and– The horizontal process of the palatine bone

• The roof is narrow and it is formed, from behind forward, by:– The body of the sphenoid– The cribriform plate of the ethmoid– The frontal bone– The nasal bone– The nasal cartilages

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The lateral wall of the noseThe lateral wall of the nose

• The lateral wall has three projections called the:– Superior

concha– Middle

concha– Inferior

concha

• The area below each concha is called a meatus.

• The lateral wall has three projections called the:– Superior

concha– Middle

concha– Inferior

concha

• The area below each concha is called a meatus.

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• The area below each concha is called a meatus.– Superior

meatus – Middle

meatus– Inferior

meatus

• The area below each concha is called a meatus.– Superior

meatus – Middle

meatus– Inferior

meatus

The lateral wall of the noseThe lateral wall of the nose

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Openings in the Superior MeatusOpenings in the Superior Meatus

• The superior meatus lies below and lateral to the superior concha.– It receives the openings

of the posterior ethmoidal air sinuses

• The superior meatus lies below and lateral to the superior concha.– It receives the openings

of the posterior ethmoidal air sinuses

• The sphenoethmoidal recess lies anterior to the body of the sphenoid bone.– It receives the opening

of the sphenoidal air sinus.

• The sphenoethmoidal recess lies anterior to the body of the sphenoid bone.– It receives the opening

of the sphenoidal air sinus.

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• The middle meatus lies below and lateral to the middle concha.– It has on its lateral wall a rounded prominence, the bulla ethoidalis.– Bulla ethmoidalis is caused by the bulging of the underlying middle ethmoidal

air sinuses, which open on its upper border.• Hiatus semilunaris is a curved cleft below the bulla.

– It leads into a funnel-shaped channel called the infundibulum– The frontal sinus opens into and is continuous with the infundibulum.

• The middle meatus lies below and lateral to the middle concha.– It has on its lateral wall a rounded prominence, the bulla ethoidalis.– Bulla ethmoidalis is caused by the bulging of the underlying middle ethmoidal

air sinuses, which open on its upper border.• Hiatus semilunaris is a curved cleft below the bulla.

– It leads into a funnel-shaped channel called the infundibulum– The frontal sinus opens into and is continuous with the infundibulum.

Openings in the Middle MeatusOpenings in the Middle Meatus

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Openings in the Middle MeatusOpenings in the Middle Meatus

• The maxillary sinus opens in the middle meatus via hiatus semilunaris.

• The anterior ethmoidal sinuses also open in the infundibulum.

• The maxillary sinus opens in the middle meatus via hiatus semilunaris.

• The anterior ethmoidal sinuses also open in the infundibulum.

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Structures related to the middle meatusStructures related to the middle meatus

• The middle meatus is coninuous anteriorly with a depression called the antrum.

• The antrum is limited above by a ridge called agger nasi.• Below and in front of the antrum is the vestibule.• It is lined by modified skin and has short hairs called vibrissae.

• The middle meatus is coninuous anteriorly with a depression called the antrum.

• The antrum is limited above by a ridge called agger nasi.• Below and in front of the antrum is the vestibule.• It is lined by modified skin and has short hairs called vibrissae.

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Openings in the Inferior MeatusOpenings in the Inferior Meatus

• The inferior meatus lies below and lateral to the inferior concha.• It receives the opening of the nasolacrimal duct. • The opening of the nasolacrimal duct is garded by a fold of mucosa,

forming an imperfect valve.

• The inferior meatus lies below and lateral to the inferior concha.• It receives the opening of the nasolacrimal duct. • The opening of the nasolacrimal duct is garded by a fold of mucosa,

forming an imperfect valve.

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Medial wall of the noseMedial wall of the nose

• The medial wall (the nasal septum) is an osteocartilaginous partition, covered by mucous membrane.

• It is formed by: – the vertical (perpendicular) plate of the ethmoid bone, – the vomer and – the septal cartilage.

• The medial wall (the nasal septum) is an osteocartilaginous partition, covered by mucous membrane.

• It is formed by: – the vertical (perpendicular) plate of the ethmoid bone, – the vomer and – the septal cartilage.

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MUCOUS MEMBRANEMUCOUS MEMBRANE

• It lines all the nasal cavity, with the exception of the vestibules (lined with modified skin).

• Two types of mucous membrane:– olfactory – respiratory

• It lines all the nasal cavity, with the exception of the vestibules (lined with modified skin).

• Two types of mucous membrane:– olfactory – respiratory

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OLFACTORY MUCOSAOLFACTORY MUCOSA

• On the lateral wall, it lines the upper surface of the superior concha and the spheno-ethmoidal recess.

• On the medial wall, it lines the superior part of the nasal septum.

• On the lateral wall, it lines the upper surface of the superior concha and the spheno-ethmoidal recess.

• On the medial wall, it lines the superior part of the nasal septum.

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RESPIRATORY MUCOSARESPIRATORY MUCOSA

• It lines the lower part of the nasal cavity.• It functions to moisten, clean and warm the inspired air.• The air is moistened by the secretion of numerous serous glands.• The air is warmed by a submucous venous plexus.

• It lines the lower part of the nasal cavity.• It functions to moisten, clean and warm the inspired air.• The air is moistened by the secretion of numerous serous glands.• The air is warmed by a submucous venous plexus.

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NERVE SUPPLY TO THE NASAL CAVITYNERVE SUPPLY TO THE NASAL CAVITY

• The olfactory nerves arise from the central axons of the olfactory nerve cells.

• They ascend through the cribriform plate to reach the olfactory bulbs.

• The nerves of ordinary sensation are branches of the ophthalmic division (CnV1) and the maxillary division (CnV2) of the trigeminal nerve

• The olfactory nerves arise from the central axons of the olfactory nerve cells.

• They ascend through the cribriform plate to reach the olfactory bulbs.

• The nerves of ordinary sensation are branches of the ophthalmic division (CnV1) and the maxillary division (CnV2) of the trigeminal nerve

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ARTERIAL BLOOD SUPPLYARTERIAL BLOOD SUPPLY• It comes mainly from branches of the maxillary artery.• The most important branch is the sphenopalatine artery.• This artery anastomoses with the septal branch of the superior labial

artery in the region of the vestibule.• This is a common site of bleeding from the nose (epistaxis).

• It comes mainly from branches of the maxillary artery.• The most important branch is the sphenopalatine artery.• This artery anastomoses with the septal branch of the superior labial

artery in the region of the vestibule.• This is a common site of bleeding from the nose (epistaxis).

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LYMPH DRAINAGELYMPH DRAINAGE

• The vestibule of the nasal cavity is drained into the submandibular lymph nodes.

• The reminder of the nasal cavity is drained into the upper deep cervical lymph nodes.

• The vestibule of the nasal cavity is drained into the submandibular lymph nodes.

• The reminder of the nasal cavity is drained into the upper deep cervical lymph nodes.

PARANASAL SINUSES

PARANASAL SINUSES

MAXILLARYFRONTAL

SPHENOIDALETHMOIDAL

MAXILLARYFRONTAL

SPHENOIDALETHMOIDAL

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DEFINITIONDEFINITION

• They are cavities inside the:– Maxilla– Frontal bone– Sphenoid bone– Ethmoid bone

• They are:– Lined with

mucoperiosteum; – Filled with air;– Communicate with

the nasal cavity.

• They are cavities inside the:– Maxilla– Frontal bone– Sphenoid bone– Ethmoid bone

• They are:– Lined with

mucoperiosteum; – Filled with air;– Communicate with

the nasal cavity.

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Functions of the Paranasal SinusesFunctions of the Paranasal Sinuses

• Reduce the weight of the skull.• Resonators of the voice.

• Reduce the weight of the skull.• Resonators of the voice.

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• The mucus produced by the mucosus membrane is drained into the nose by the ciliary action of the columnar cells.

• It is also helped by siphon action created during blowing of the nose.

• When the apertures of the sinuses are blocked or when they are filled with fluid, the quality of the voice becomes markedly changed.

• The mucus produced by the mucosus membrane is drained into the nose by the ciliary action of the columnar cells.

• It is also helped by siphon action created during blowing of the nose.

• When the apertures of the sinuses are blocked or when they are filled with fluid, the quality of the voice becomes markedly changed.

Drainage of Mucus and Function of Paranasal Sinuses

Drainage of Mucus and Function of Paranasal Sinuses

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MAXILLARY SINUSMAXILLARY SINUS

• It is located within the body of the maxilla behind the skin of the cheek.

• It has a pyramidal form:

• The roots of the:– First premolar tooth– Second premolar

tooth– Third molar tooth– Canine tooth

(sometimes)• - Project into the

maxillary sinus• Tooth extraction can

produce a fistula.• Tooth infection can

produce sinusitis.

• It is located within the body of the maxilla behind the skin of the cheek.

• It has a pyramidal form:

• The roots of the:– First premolar tooth– Second premolar

tooth– Third molar tooth– Canine tooth

(sometimes)• - Project into the

maxillary sinus• Tooth extraction can

produce a fistula.• Tooth infection can

produce sinusitis.

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MAXILLARY SINUSMAXILLARY SINUSThe maxillary sinus opens in the middle meatus through the semilunar hiatus.The maxillary sinus opens in the middle meatus through the semilunar hiatus.

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NERVE SUPPLY

MAXILLARY SINUS

NERVE SUPPLY

MAXILLARY SINUS

• The mucous membrane of the maxillary sinus is supplied by the:– Superior

alveolar and the

– Infraorbital nerves.

• The mucous membrane of the maxillary sinus is supplied by the:– Superior

alveolar and the

– Infraorbital nerves.

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FRONTAL SINUSFRONTAL SINUS

• The frontal sinuses (two) present within the frontal bone.• They are separated by a bony septum (frequently deviated to one

side).• Each sinus is roughly triangular.• It extends:

– Upward above the medial end of the eyebrow– Backward into the medial part of the roof of the orbit.

• Each frontal sinus opens into the middle meatus

• The frontal sinuses (two) present within the frontal bone.• They are separated by a bony septum (frequently deviated to one

side).• Each sinus is roughly triangular.• It extends:

– Upward above the medial end of the eyebrow– Backward into the medial part of the roof of the orbit.

• Each frontal sinus opens into the middle meatus

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SPHENOIDAL SINUSESSPHENOIDAL SINUSES

• They are two in number• They lie within the body of the sphenoid bone.• Each sinus opens into the sphenoethmoidal recess above

the superior concha.• The mucous membrane is supplied by the posterior

ethmoidal nerves.

• They are two in number• They lie within the body of the sphenoid bone.• Each sinus opens into the sphenoethmoidal recess above

the superior concha.• The mucous membrane is supplied by the posterior

ethmoidal nerves.

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ETHMOIDAL SINUSESETHMOIDAL SINUSES

• They are contained within the ethmoid bone.• Only a thin layer of bone separates these sinuses from the orbit.• Infection can readily spread from the ethmoidal sinuses into the orbit.

• They are contained within the ethmoid bone.• Only a thin layer of bone separates these sinuses from the orbit.• Infection can readily spread from the ethmoidal sinuses into the orbit.

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ETHMOIDAL SINUSESETHMOIDAL SINUSES

• They are divided into three groups: anterior, middle and posterior.

• The anterior group drains in the infundibulum.

• The middle group drains in the middle meatus (on or above bulla ethmoidalis).

• The posterior group drains in the superior meatus.

• They are divided into three groups: anterior, middle and posterior.

• The anterior group drains in the infundibulum.

• The middle group drains in the middle meatus (on or above bulla ethmoidalis).

• The posterior group drains in the superior meatus.

The mucous membrane of the ethmoidal sinuses is supplied by the anterior and posterior ethmoidal nerves.

The mucous membrane of the ethmoidal sinuses is supplied by the anterior and posterior ethmoidal nerves.

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Paranasal Sinuses and Their Site of Drainage Into the Nosea

Sinus Site of DrainageMaxillary sinus Middle meatus through hiatus semilunaris

Frontal sinuses Middle meatus via infundibulum

Sphenoidal sinuses Sphenoethmoidal recess

Ethmoidal sinuses    Anterior group Infundibulum and into middle meatus

    Middle group Middle meatus on or above bulla ethmoidalis

    Posterior group Superior meatus

Paranasal Sinuses and Their Site of Drainage Into the Nose

INFECTION OF THE NASAL CAVITY (RHINITIS)

• Infection of the nasal cavity may spread to:– The paranasal

sinuses;– Via the nasopharynx to

the auditory tube and the middle ear;

– To the anterior cranial fossa (via the cribriform plate) – and to produce meningitis.

NOSE BLEEDING (EPISTAXIS)

• The most common cause is nose picking.• May be arterial or venous in origin.• Often occurs from the anteroinferior

portion of the septum and involve the septal branches of the sphenopalatine and facial vessels.

INFECTION OF PARANASAL SINUSES (SINUSITIS)

• A common complication of nasal infection.

• Rarely, it could be a complication of apical dental abscess (for the maxillary sinus).

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