e.n.t 5th year, 1st lecture (dr. yousif chalabi)
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Dr. Yousif ChalabiDr. Yousif Chalabi
DLO, FICS, FICMS, CABSLRODLO, FICS, FICMS, CABSLRO
Embryology of the noseEmbryology of the nose
The nose develops from frontonasal process The nose develops from frontonasal process which grows between the primitive forebrain and which grows between the primitive forebrain and the roof of the stomodium and olfactory placodes the roof of the stomodium and olfactory placodes which is depressed to form olfactory pits and which is depressed to form olfactory pits and maxillary process which groes ventrally from the maxillary process which groes ventrally from the dorsal end of the mandibular arch (1dorsal end of the mandibular arch (1stst visceral visceral arch). The paranasal sinuses as outpouching of arch). The paranasal sinuses as outpouching of the nasal mucous membrane, the began to the nasal mucous membrane, the began to appear at the third to fourth fetal month growing appear at the third to fourth fetal month growing during childhood and fully developed at 20 yrs. of during childhood and fully developed at 20 yrs. of age.age.
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Bony constituentsBony constituents; ; support the upper part of the external nose and support the upper part of the external nose and
they are:they are:
Nasal processes of Nasal processes of the frontal bonesthe frontal bones. .
Nasal bones .Nasal bones .
Ascending processesAscending processes of the maxillaeof the maxillae. .
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Cartilaginous Cartilaginous constituentsconstituents : :Support the lower Support the lower part of the external nose. part of the external nose. They are:They are:
1.1.Upper lateral cartilages.Upper lateral cartilages.
2. lower nasal cartilages.2. lower nasal cartilages.
3. Quadrilateral cartilages3. Quadrilateral cartilages
of nasal septum.of nasal septum.
4. Alar cartilages.4. Alar cartilages.
The cartilages are connected with each other and The cartilages are connected with each other and with the bones by continuous perichondrium and with the bones by continuous perichondrium and periosteum .periosteum .
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External noseExternal noseIs pyramidal in shape, itIs pyramidal in shape, it’’s shape is s shape is maintained by skeletal frame maintained by skeletal frame workwork..
Anterior naresAnterior nares;;Situated in the base ofSituated in the base of
the nose and openthe nose and open downwards, they aredownwards, they are
separated by (columella)separated by (columella),, a strip of skin, connectivea strip of skin, connective tissue and medial crura oftissue and medial crura of the lower lateral cartilagethe lower lateral cartilage..
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Skin Skin ; ; Thin over the upper part of the Thin over the upper part of the
nose ,and thicker over the lower nose ,and thicker over the lower cartilaginous part ,where it contains cartilaginous part ,where it contains large sebaceous glandslarge sebaceous glands . .
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Muscles of external noseMuscles of external nose:: The nose has a number muscles which in man
has vestigial importance. Nerve supply: they are all supplied by branches
of facial nerve.Arterial supply: all supplied by maxillary and
facial arteries.
Venous drainage: through facial and ophthlmic veins they drain to cavernous sinus.
Lymphatic drainage: either follows anterior facial vein and opens in to submandibular
nodes, or drains to preauricular lymphnodes.
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Nasal fossae:Nasal fossae:** The right and left nasal fossae (cavities) The right and left nasal fossae (cavities)
are separated by the nasal septum. are separated by the nasal septum.
*The nasal fossa includes only that part *The nasal fossa includes only that part which is lined with mucous membrane. which is lined with mucous membrane.
* Each fossa communicates with:* Each fossa communicates with:1. 1. The paranasal sinuses, The paranasal sinuses, through their through their
Ostia.Ostia.
2- The nasopharynx, 2- The nasopharynx, through the posterior through the posterior choanae.choanae.
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Boundaries of posterior choana:Boundaries of posterior choana:
Each posterior choana is bounded:Each posterior choana is bounded:**AboveAbove : :by body of sphenoid and ala of vomer,
*Below*Below: : by posterior margin of horizontal part of palatine bone,
*Laterally*Laterally: : by medial pterygoid plate of sphenoid bone,
*Medially*Medially: : by posterior
free margin of vomer.
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Boundaries of nasal fossaBoundaries of nasal fossa FloorFloor:1. palatine process of maxilla in the anterior
three quarters.2. Horizontal part of palatine bone in posterior
one quarter.
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RoofRoof (very narrow) : Anteriorly: Inbetween: Cribriform plate of ethmoid, Nasal
process of through which fiberes of frontal
bone. olfactory nerve pass.
Posteriorly:Body of SphenoidBone.
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MediallyMedially: : there is nasal septum, which lies in or near the mid line.
The three main constituents are :The three main constituents are :
11--Perpendicular plate of ethmoidPerpendicular plate of ethmoid , ,above and behindabove and behind..
22-Vom
er b
elow
and
beh
ind.
-Vom
er b
elow
and
beh
ind.
3-Quadrilateral cartilage in the
Quadrilateral cartilage in the
angle between first and second.
angle between first and second.
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Other bones which contribute to the Other bones which contribute to the formation of the septum are:formation of the septum are:
1-Anterior nasal spine of maxilla
2-Nasal crests of maxillary and palatine bones
3-Nasal spine of frontal bones
4-Rostrum and crest of sphenoid bone
5-Crests of nasal bones
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Lateral wallLateral wall: : is formed by 1-Medial wall of maxilla.2-Lateral mass of ethmoid and lacrimal bone. Other contribution are derived from:* Ascending process of maxilla (anteriorly).* Perpendicular part of palatine bone and behind it, medial pterygoid
process of sphenoid posteriorly.
1-Medial wall of maxilla
2-Lateral mass of ethmoid and
lacrimal bone
Perpendicular part of palatine bone
medial pterygoid process of sphenoid
Ascending process of maxilla
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The main features of lateral wall are:
1. Three turbinates superior, middle, and inferior.2. Three meatus named after the turbinates. each lies below
and lateral to corresponding turbinate.3. Spheno-ethmoidal recess lies above the superior turbibates
and receives the ostium of sphenoidal sinus.4. superior meatus contains the ostia of posterior ethmoidal
cells.
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5. Middle meatus is the most complex and by far the most important, because:
1- The ostia of maxillarymaxillary, , anterior ethmoidalanterior ethmoidal, , and frontalfrontal sinuses open into it.
2- The atriumatrium is forward continuation of middle meatus.3- The agger nasiagger nasi is curved ridge lying above the atrium.
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4- The bulla ethmoidals is a smooth rounded mass formed by anterior ethmoidal cells, the ostia of these cells open on to the bulla.
5- The hiatus semilunaris lies below and infront of bulla and leads forwards in to the infundibulum. it is bounded below by uncinate process of ethmoid.
* Inferior meatus receive the nasal opening of naso-lacrimal Inferior meatus receive the nasal opening of naso-lacrimal duct. duct.
bulla ethmoidals
hiatus semilunaris
uncinate process
naso-lacrimal duct .
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Superior meatus occupies the posterior third of lateral wall.
Middle meatus occupies the posterior two thirds,
The inferior meatus runs the length of the lateral wall.
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The olfactory cleft:The olfactory cleft: occupies the area between the superior turbinate, cribriform plate and the corresponding area of the septum and it is lined by specialized olfactory epithelium.
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Paranasal sinuses:These are air spaces within certain bones of the skull.
Four on each side:
They are lined with a mucous membrane continuous with that of the corresponding nasal fossa through their ostia.
(labyrinth)
(labyrinth)
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Humidifying and warming the inspired air.
Regulation of intranasal pressure. Increasing surface area for olfaction. Lightening the skull. Adding resonant effect to voice. Absorbing shock. Contributing to facial growth.
Function of Paranasal Function of Paranasal SinusesSinuses The exact function of PNSs are uncertain but may have The exact function of PNSs are uncertain but may have
role inrole in::
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Maxillary sinus:*It is the largest of the sinuses,
with an average capacity of about 15 ml in the adult.
* Is pyramidal in shape and
occupies the body of the maxilla.
* The base lies medially,
the apex is in the zygomatic portion of the maxilla.
* Medial wall is the wall
between the sinus and the nasal fossa.
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* Floor Floor :is formed by the alveolar
process and hard palate: Œ- In children the floor lies at, or above, the level of the floor of the nasal fossa. Œ- In adults it lies about 1.25cm below the floor of the fossa.
Œ- The roots of several teeth may project into, or even perforate, the floor.
1,25cm
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The ostia of maxillary sinus:*Main ostium is situated high up between the medial wall and roof of the cavity. It opens into the hiatus semilunaris.*Accessory ostia are sometimes present, behind the main one. Both main and accessory ostia are surrounded by a wide area of mucous membrane unsupported by bone.
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Relations of maxillary sinus:1*1*Orbit:Orbit: is separated from
the antrum by the thin roof of the sinus which contains the infraorbital nerve.
2*2*Teeth:Teeth: may produce
elevations in the floor of the sinus and the number of related teeth depends on the size of the antrum. The second premolar and first molar are usually related.
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3*3* Middle meatus of nose:Middle meatus of nose:
is related to the upper
part of the antrum.
4*4* Inferior meatus of nose:Inferior meatus of nose: is separated from the middle part of its medial wall by bone, which is usually thick in front and below,but thinner above and behind.
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5*5* maxillary arterymaxillary artery : : is related to the posterior
wall, where it occupies the pterygopalatine fossa. It may be approached through the antrum for ligature.
6*6* Maxillary division of Maxillary division of
the Vth cranial nerve:the Vth cranial nerve:
also traverses the pterygo-
palatine fossa.
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7*7* Nasolacrimal duct:Nasolacrimal duct:
passes downwards,
medial to the antrum, to open into the inferior meatus.
maxillary sinus
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Ethmoidal sinuses (labyrinths)*Consist of a number (approximately 7-15) thin-walled
cavities within the lateral masses of the ethmoid bones, and sometimes in the agger nasi and middle turbinate.
*The cells may invade any of the surrounding bones, including the frontal, sphenoid and maxillary bones.
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There are two groups of cells:There are two groups of cells:1-Anterior. Usually small and numerous. They open into
the upper part of the hiatus semilunaris or on to it, or above the bulla ethmoidalis. So Secretions drain into the middle meatus.
2-Posterior. Usually large and few. They open into the superior meatus.
2
1
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Frontal sinus:*Should be regarded as an upward extension of an anterior ethmoidal cell.
*It occupies a very variable extent of the frontal bone and may be partly loculated.
*Its average capacity is about 7 ml in the adult.
* The right and left sinuses are often asymmetrical.
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*They are separated by a thin bony septum, which may be deficient in part. * The sinus may invade the orbital plate of the frontal bone and occasionally it extends to the optic foramen.
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The frontonasal duct:*It passes through the anterior part of the ethmoidal labyrinth.
* Its length and curvature vary considerably.
* Its lower end (ostium) usually opens in to the infundibulum, less often independently above this level.
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Relations of frontal sinuses:Anterior cranial fossa: separated from the sinus by the compact bone of its posterior wall.
Orbit: lies below the floor of the sinus. This is also compact bone which may rarely be deficient.
Skin and periosteum of forehead: cover the anterior wall, which is of diploic bone and is related To supratrochlear andsupraorbitalnerves.
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Sphenoidal sinus:*Lies behind the upper part of the nasal fossa.* It occupies the body, and some times the wings and pterygoid processes, of the sphenoid bone. * The average capacity is about 7 ml in the adult. * The right and left sinuses are rarely symmetrical.* They are separated by a septum which may be deficient in part and is often oblique.
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The ostium of sphenoid sinus:
*situated in the upper part of the anterior wall of the sinus. *It communicates with the superior meatus indirectly through the sphenoethmoidal recess.
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Relations:*Cavernous sinus lies laterally containing the: IIIrd,
IVth, Vth (ophthalmic and maxillary- divisions) and VIth cranial nerves,
internal carotid artery
optic nerve
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*Above the sinus there are:
Pituitary gland,
optic chiasm,
frontal lobe of brain
olfactory tract
The pituitary gland may be approached surgically through the sinus.
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Mucous membrane of nose and paranasal sinuses:The mucous membrane of the nose is of two types:1. Respiratory mucosa:*This lines the lower two-thirds of the nasal septum, the lateral wall of the nose below the superior turbinate and the floor of the nasal fossa.
*It is pink in colour and is covered by a ciliated, columnar epithelium.
*It also extends into the sinuses , through their Ostia, and is thinner
there.
* It is also continuous with the epithelia of the naso-lacrimal duct
and Eustachian tube .
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Blood supply of nose and paranasal sinuses :Blood supply of nose and paranasal sinuses :Arterial supply:Arterial supply:The nasal fossae and paranasal sinuses are supplied by
branches of the external and internal carotid arteries:
A. Derivatives of external carotid artery:A. Derivatives of external carotid artery:
1-Sphenopalatine artery1-Sphenopalatine artery: via the maxillary artery supplies the turbinates and meatus of the nose and most of the septum.
Sphenopalatine artery
Maxillary artery
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22--Greater palatine arteryGreater palatine artery:: a branch of the maxillary artery contributes branches to the lateral nasal wall and
(via the incisive canal )to the anterior part of the septum.
incisive canal
Greater palatine artery
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3-Superior labial artery3-Superior labial artery:: *A branch of the facial artery. It sends branches to the tip of the septum and the alae nasi. *Its anastomosis with a branch of the spheno- palatine artery and the greater palatine artery (`the artery of epistaxis') Forms Kiesselbach's plexus, in Little's area.
Septal branches of posterior
ethmoidal arterySeptal branch
of anterior Ethmoidal
artery
Little's area, with plexus of vessels
Septal branch of superior labial artery
Septal branches of sphenopalatine
artery
Greater palatine artery
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4-Infraorbital and superior dental arteries:4-Infraorbital and superior dental arteries: *branches of the maxillary artery. *They supply the maxillary antrum.
5-Pharyngeal branch of 5-Pharyngeal branch of maxillary artery:maxillary artery: supplies the sphenoidal sinus.
Infraorbital artery
superior dental arteries
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B. Branches of internal carotid artery:
Anterior and posterior ethmoidal arteries:Anterior and posterior ethmoidal arteries: *branches of the ophthalmic artery.
* They supply the roof of the nose, anterior parts of the septum and lateral wall of thenose, and the ethmoidal and frontal sinuses. *Bleeding from these vessels is seen above the level of the middle turbinate.
Anterior ethmoidal artery
posterior ethmoidal artery
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Venous drainage:Venous drainage:The veins form a cavernous plexus beneath the mucous
membrane
They open into:They open into:1-Sphenopalatine vein and anterior facial vein, from the
plexus.
2-Ophthalmic veins, from the ethmoidal veins.
3-Veins on the orbital surface of the frontal lobe of the brain, through
the foramina in the cribriform plate.
4-Superior sagittal sinus, through the foramen caecum.
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Vascular arrangements of mucous membrane:*Arterioles: lie in the deeper part of the subepithelial connective
tissue. They are arranged in longitudinal rows.* Capillaries: lie in networks under the epithelium and around the glands. * Sinusoids: receive blood from thecapillary networks.* Venous plexuses: also lie in the deeper part of the subepithelial connective tissue. They drain the sinusoids.* Venules: collect blood from the plexuses.
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Nerve supply of nose:Nerves of common sensation are derived from: 1. Branches of the Vth cranial nerve:1. Branches of the Vth cranial nerve:*Anterior ethmoidal nerveAnterior ethmoidal nerve: A branch of ophthalmic (1st)division. It enters the nasal cavity through theanterior ethmoidal foramen and divides in to:
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A-Medial branch: which supplies the anterior part of the
septum.B-Lateral branch:
which supplies the anterior part of the
lateral wall of the nose, and the anterior
parts of the middle and and inferior
turbinate.
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Lymphatic drainage of nose and Lymphatic drainage of nose and paranasal sinuses:paranasal sinuses:
The lymphatic vessels arise from a continuous network in the superficial part of the mucous membrane.
Subimandibular lymph nodes:Subimandibular lymph nodes: collect lymph from the external nose and anterior part of the nasal cavity.
Upper deep cervical nodes:Upper deep cervical nodes: drain the rest of the nasal cavity, either directly or through the retropharyngeal nodes.
Physiology of the NosePhysiology of the Nose
Generally the nose serves the demand for 9 functions:Generally the nose serves the demand for 9 functions: Respiration: the nose is the primary passage for the Respiration: the nose is the primary passage for the
inspiratory air current in a continuous stream over the inspiratory air current in a continuous stream over the inferior and middle turbinate where it’s divided by inferior and middle turbinate where it’s divided by anterior ends of these turbinates into two streams anterior ends of these turbinates into two streams above and below each turbinate to increase the above and below each turbinate to increase the contact surface with the mucosa for better contact surface with the mucosa for better conditioning of the inspired air to the lungs, conditioning of the inspired air to the lungs, considering that eddie’s stream which may happen for considering that eddie’s stream which may happen for a reason or another is not ideal for air passage and it a reason or another is not ideal for air passage and it may form obstruction to the subsequent current may form obstruction to the subsequent current behind it.behind it.
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Purification of the inspired air: where the large particles are Purification of the inspired air: where the large particles are detected by the vibrassies of the nasal vestibule and the smaller detected by the vibrassies of the nasal vestibule and the smaller particles are dealt with by lysosomal enzymes, macrophages, and particles are dealt with by lysosomal enzymes, macrophages, and the antibodies in the mucosal blankets of the nasal fossa.the antibodies in the mucosal blankets of the nasal fossa.
Humidification and warming of the inspired air: a function which is Humidification and warming of the inspired air: a function which is carried out by the submucosal venous plexus of sinusides and carried out by the submucosal venous plexus of sinusides and lakes of the inferior and middle turbinates by transduction of the lakes of the inferior and middle turbinates by transduction of the heat to the cold inspiratory air and from the air to the sinusides of heat to the cold inspiratory air and from the air to the sinusides of the hot air.the hot air.
Olfaction: which is carried out by the superior part of the nasal Olfaction: which is carried out by the superior part of the nasal fossa in the olfactory area where the odours of nearly 30 oderant fossa in the olfactory area where the odours of nearly 30 oderant types are carried by the olfactory nerve ending across the types are carried by the olfactory nerve ending across the olfactory filament to the olfactory bulb where it’s perceived as an olfactory filament to the olfactory bulb where it’s perceived as an odour a sense which is intimately related to taste (agusia) sense .odour a sense which is intimately related to taste (agusia) sense .
The nose forms a part of the buttress function of the facial The nose forms a part of the buttress function of the facial skeleton where it may receive the first impact of an assault to the skeleton where it may receive the first impact of an assault to the nose.nose.
Cosmoses of the nose: the nose occupying the middle part of the Cosmoses of the nose: the nose occupying the middle part of the face, gives the main feature of cosmoses to the face making it face, gives the main feature of cosmoses to the face making it one of the main part of the body where plastic surgery most one of the main part of the body where plastic surgery most frequently carried on.frequently carried on.
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Adding tone to the speech: the voice is produced by voice Adding tone to the speech: the voice is produced by voice box larynx and it’s formulated into a meaningful speech by box larynx and it’s formulated into a meaningful speech by supralaryngeal vocal apparatus of pharyngeal, palatal, supralaryngeal vocal apparatus of pharyngeal, palatal, lingual, and lip muscles. Main tone of this spoken speech is lingual, and lip muscles. Main tone of this spoken speech is added by the nose.added by the nose.
Lightening of the facial skeleton over the neck: the nose and Lightening of the facial skeleton over the neck: the nose and the paranasal sinuses by the virtue of their pneumotization the paranasal sinuses by the virtue of their pneumotization lightens the facial bone weight over the neck.lightens the facial bone weight over the neck.
Nasal cycle: this is the function of alternate opening and Nasal cycle: this is the function of alternate opening and obstruction of one nasal fossa in turn with the other lasting obstruction of one nasal fossa in turn with the other lasting for 3-8 hrs. (mainly 4 hrs.), this function is carried by the for 3-8 hrs. (mainly 4 hrs.), this function is carried by the autonomic nervous supply to the nose where by sympathetic autonomic nervous supply to the nose where by sympathetic overactivity with parasympathetic underactivity produce overactivity with parasympathetic underactivity produce venous engorgement of turbinal submucosal venous plexus venous engorgement of turbinal submucosal venous plexus of sinusides and lakes and consequently turbinal of sinusides and lakes and consequently turbinal engorgement causing obstruction of the lower nasal fossa engorgement causing obstruction of the lower nasal fossa and an opposite event in the upper nasal fossa causing and an opposite event in the upper nasal fossa causing widening and consequently opening of that fossa.widening and consequently opening of that fossa.
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