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Today we will talk about the nasal cavity and the palate which are the roof
of the oral cavity which Is located between the oral cavity and the cranial
cavity
The nasal cavity is the passage way between the outside environment and thepharynx posteriorly
(The pharynx is a very large structure that divides posteriorly into
1- Behind the nasal cavity, we call it the nasal part of the pharynx
(nasopharynx)
2- Part of the pharynx behind the oral cavity (oropharynx)
3- Behind the larynx called (laryengopharynx)
** So you can see that the pharynx is a large structure relatively speaking tothe larynx
So the nose is the structure that extend anteriorly outside all the way
posteriorly until the nasal part of the pharynx , Its covered by skin from
outside and by mucus membrane from inside ( mucus membrane covering the
inside of the nose is covering by specific type of epithelium called
respiratory epithelium which is psedustratified columnar epithelium
ciliated )
** In order to understand the nasal area we subdivide the nose into 2 parts,
1- The external nose which is the prominent part of the face that you see
2- The cavity within the skull that we refer to it as the nasal cavity (the
major part)
* The external nose
Its made of bony and cartilaginous part, the bony part is more posteriorly
and it is usually formed by:-frontal process of maxilla.
-the nasal bone (2 small plates) on the bridge or the dorsum of the nose
-the nasal process of the frontal bone
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However the more prominent part in the face is made cartilaginously by the
cartilages that we refer to them lateral cartilages ( lateral alar and septal
cartilages )
For more description we call them1- Upper lateral,
2- Lower lateral that are the alar or alar cartilages and those are u shaped
so they are extended from the lateral to the medial part of the nose with 2
crura (2 legs, lateral and medial crus)
3- And there is another smaller group we refer to them lesser alar
* So the alar are two greater one and behind it there is the lesser alar
** we have one in the middle that helps in separating the nasal cavity intotwo spaces right and left nasal cavity so we call it the septal cartilage and
this one in living human is considered as a part of the nasal septum because
it helps in separation the 2 nasal cavities ,,
The nasal septum is formed by 2 bony parts the vertical or perpendicular
plate of ethmoid superiorly and the vomer inferiorly and more anteriorly in
the prominent part in the external nose you will find the cartilage there
which is called septal cartilage ( you can see it in a living human not in a skull
because its cartilaginous )
**The nasal cavity
** It extend from the outer nares (nostrils) (external nares) which are 2
openings from the outside into the nose
** The inner nares ( choanae ) are the openings between the nasal cavity
and the pharynx behind.
So it extend from the external nares to the posterior aspect of choanae (its
demarcate by the end of the conchae, those elevations or shelves on the
lateral walls of the nasal cavity we refer to them as conchae)
So the boundaries
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# IN the medial wall we have the nasal septum.
#IN the lateral wall:
1- We can see anteriorly a depression area; we refer to it as the vestibule(more related to the external nose)
**The vestibule are characterized by covering by a skin so part of the skin
folded back inside into the lateral wall of the nose and thats why you can
see hair follicles and hair growing inside the nose behind the vestibule there
is the conchae.
2- Conchae: a Latin word that means shell (superior, middle and inferior)
they are found in the lateral walls also
And each space covered by each conchae we call it meatus which is a passage
way
Superior meatus covered by superior conchae
Middle meatus covered by middle conchae
Inferior meatus covered by inferior conchae
The posterior wall of the conchae demarcate the end of the nasal cavity so
the posterior part of the conchae is the end of the nose where we find the
choanae (the opening from the nose into the nasopharynx)
# the roof is made of:
1- Part of sphenoid bone.
2- The ciribriform plate of ethmoid bone.
3- The frontal bone and nasal bone.
# the floor is the hard palate (the floor of the nasal cavity is the roof of
the oral cavity)
*the soft palate separating the nasopharynx from the oropharynx
*hard palate is made of palatine process of maxilla bone and horizontal plate
of frontal bone
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** Nasal conchae and Meatus
As I told you the conchae are bony projections that project inferiorly like
shelves.
* Superior conchae and middle conchae comes from ethmoid bone
* Inferior one is a separate bone
Beneath each concha we have a space we call it meatus.
The conchae are there to protect the opening of the paranasal sinuses which
opens into the meatus, not the air sinus!! Whats the difference???
** paranasal sinuses are air sinus that will open into the nose because wehave additional air cell which called mastoid air cells that will open in the
middle ear so the
paranasal sinuses are :
1- ethmoidal air cell ( anterior , middle and posterior)
2- the frontal
3- the sphenoid
4- the maxillary which is the largest one
1- In the superior meatus we will have the opening of posterior ethmoidal air
cells.
2- In the middle we have the middle and anterior air cells, the frontal and
maxillary.
So most of the air sinuses opens in the middle meatus
** The arrangement of ethmoidal air cells is oblique and going in a horizontaland vertical way,
So # the anterior most anterior inferior# the middle more posterior superior
# the posterior is the more posterior and the most superior one
(because its the most superior one)
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4- in inferior meatus there is no air sinus opening into it
** There is another opening that connect the lacrimal sac with the
inferior meatus
lacremal apparatus is containing the lacremal gland that gonna secrete
the tears that will be collected in the medial inferior angle of the orbit in
the lacremal sac when the sac is filled the tears start to drop and
through a duct connecting the orbit with the inferior meatus of the nose
(nosolacrimal duct) so the tears start to fall from the nostrils thats
why when you cry you have a runny nose
* We still have the sphenoid air sinus >>> they open into an angle
between sphenoid and ethmoid bone in a place above the superiorconchae we call it sphenoethmoidal recess ( pocket ) that form because
of the angulation between the sphenoid and ethmoid bone
There is another opening that connect the lacrimal sac, IF YOU
REMEMBER (the lacrimal apparatus is made up of lacrimal glandes &
sacs ,the lacrimal glands secret the tears which will accumulate in the
lacrimal sac in the inferior &medial corner of the orbit , when the
lacrimal sac is filled now , the tears start to drop down outside the eye
and through a duct that is called nasolacrimal duct ,connect the orbit
with the inferior meatus of the nose ,so the tears start to drop down
from the nostrils, that is why when you start to cry, you have a runny
nose .
SO, in the superior meatus
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You gonna be asked about all of these air cells, and you must be able to
distinguish each of them.
Q: posterior ethmoidal air cells open into???
1- sphenoethmoidal recess2-superior meatus
3- inferior meatus
ANSWER
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to pass through it and open into the nose, this opening called the
SPHENOPALATINE FORAMEN.
The sphenopalatine foramen usually located behind the superior and
middle conchae, sometime may located behind the middle concha but most
of the time it is located in the gap (area) between sup & middle conchaeSO , in the lateral wall of the nose there is sphenopalatine foramen allow
the passage of maxillary artery into the nasal cavity , once it enters
there, it is called sphenopalatine artery (which is terminal branch of
maxillary artery) , and here it is starting to provide blood supply to the
lateral wall & the nasal septum posteriorly.
2)Now, the anterior part of the nasal cavity is supplied by septal branch
from superior labial artery which is branch from facial artery.
3)The roof of the nasal cavity ( that separates the cranial cavity from
nasal cavity ) , there is 2 artery coming from there , called :
1- anterior ethmoidal artery 2- posterior ethmoidal artery
both of them come from ophthalmic artery , which is branch from ICA
and it locate within the orbit .
4) The floor of the nasal cavity (which is the hard palate) supplied by
greater palatine artery
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very common area for bleeding ( most of the nasal bleeding
EPISTAXIS take place in this area where all arteries unite).
What are the causes for epistaxis???
there are more than 100 causes , so we will not gonna mention them here ,
but you have to know that , these causes are arranged from very simplecauses like picking up with your nose , or from injury to the artery or vein
, or from trauma
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Note: The smell occurs in the superior part of the nasal cavity.
The general sensation now comes from the trigeminal nerve:
1. Ophthalmic nerve: V1 most anterior part and prominent one
When you touch the tip of the nose, its V1
2. Maxillary nerve: the remaining Middle and Inferior part of the nasal
cavity.
Paranasal sinuses
You can read it by yourself they dont have any thing .
1.sphenoid 2.frontal 3.maxillary 4.ethmoidallargest one is the maxillary ,,
we afraid when we have Sinusitis which may lead and spread to the
Meninges Leading into infection of the meninges (meningitis )
For more details and information please go to the slides and the 3rd
script of the first exam.
Palate :
when we speak about the palate we know that is form the floor of thenasal cavity and the roof of the oral cavity , it made by 2 parts hard and
soft one
* HARD PALATE : containing hard tissue bone
*SOFT PALATE : containing soft tissue muscles
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The epithelium found in the nasalcavity is respiratory epipsudosratified columnar epi except upper region or upper third
just above the sup concha the epiwill become simple columnarolfactory epithelium and containthe ends or receptor of the olfactorynerve fibers .
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The first 3 quadrants of the palate is hard and the remaining is soft
Hard Palate:
Composed of:
-Mucous Membrane: that covers the surfaces
- Palatine aponeurosis FIBROUS sheet which made the fibrous part of
the soft palate which is dens regular connective tissue with epithelial
lining.
Its the key stone of the soft palate expanded tendon of Tensor veli
palatine ( nerve supply V3) In addition there is another muscles that
covered with this mucous membrane together it will become 5 muscles
First one of them the TENSOR VELI PALATINE :
2 from each side come down from the base of the skull all the way to
reach the trigoid hamulus extended part of the medial part of the
trigoid plate of sphenoid bone.
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Hard palate:
consist of the palatine process of maxilla
and horizontal palate of the palatine
Soft palate:
Fibro muscular fold covered with mucosa
& attached to post. Border of Hard palate
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*From the base of the skull there is another muscle that will descend all the
way to this aponuroese if it contract it will elevate the soft palate So we call
it Levator veli palatine
2 muscles above: Anterior: tensor veli palatineposterior: levator veli palatine
2 muscles going below: anterior: Palatoglossus m. from the soft palate to
the tongue posterior: Palatopharyngeus m. from the soft
palate all the way to the pharynx and join the wall of it.
The 5th one uvula: a conical projection from post. Border of soft Palate
if you cut it you will find a mucus membrane surrounded a muscle.
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The function of the hamulus toallow the tensor palatine to go orturn horizontally to make the 2tendons of the muscle in each sidemeet each other ,, because thetensor palatine come verticallyfrom the base of the skull .
when this muscle contract thetendons tense and forming thefoundation of the soft palateplalatine aponeurosis : formd bythe 2 tendons of the tensor velipalatinethe teigoid hamulus found only inthe medial teigoid plateno one in the lateral cus its attachto the 2 muscles of mastication(lateral and medial. terigoid
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Palatoglossus m and the Palatopharyngeus m Important clinically Why?!
they are mucus membrane covered and this membrane form a folds when it
each them so they are demarcating the tonsilar bed where dose the
palatine tonsils found,, if you dont see them in the mouth of the patient that
is Healthy state but if they have any enlargement in size that will betonsillitis
Arterial blood supply to the palate :
1. Greater palatine artery for the hard palate
2. Lesser palatine artery for the soft palate
both of them come from the descending palatine artery which come from
the Maxillary artery and pass from the greater and lesser palatine foramens
*Additional Arteries*
1. From the ECA ,, Ascending pharyngeal artery when it go to the pharynx
2.From Facial artery ,, first branch Ascending palatine artery from superior
Palatine Innervation :
1. Greater palatine nerve : hard palate
2. Lesser palate nerve : soft palate
3.nasopalatine nerve : Incisive nerve supply the primary palate which is the
first part formed of the palate found behind the anterior teeth and have a
folds ,,
There is another important area in the palate Vibrating Line : important of
the prosthodontics in the upper teeth , its the border between the movable
and non-movable part of the soft palate
the palate is fibro muscular the tendons part is fixed area when you open
your mouth and say ahhhhhh you see the vibration in the soft palate as
the muscle contract but in the first 2mm in the soft palate we have palatine
aponurouses, it is non-movable but the muscular one is movable, so the
vibration line is the junction between the movable and non-movable parts ofthe soft palate.
Posterior edge of the upper denature must be in the non-movable part of the
soft palate because it depend on the negative pressure.
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Done by: Heba Radaideh, Haya Momani & Sondos Harbeih.
Edited by: C.W.T
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