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Neuro: 8:00 - 9:00
Thursday, March 12, 2009
Dr. Bimczok
Pterygopalatine Fossa, Nose and Paranasal Sinuses
Abbreviated Terms: PPF (Pterygopalatine Fossa)
Scribe: Brittney Wise
Proof: Laura Adams
Page 1 of 10
NOTE: The italicized words are the notes located under each slide. She did not necessarily address all of these notes in
class but I included them in this transcript for convenience. They were definitely a study aid for the 1st exam because
many of the test questions come from the notes below the slides.
I.
Introduction [S1]: This is a frontal section of the head. You can see a few structures that you will be able to ID at
the end of this lecture.
II. [S2] Pterygopalatine Fossa, Nose, Paranasal Sinuses, and Dissection
a. Pterygopalatine Fossa – not the easiest region in the heads
b. Nose
c. Paranasal Sinuses
d. Dissection
III. [S3] Pterygopalatine Fossa
a. She has made an analogy for this: “A crossroads in a crevice”
b. Showed 5 points south being a crossroads and symbolizing the PPF. This is where the maxillary nerve enters
and goes off in many directions. At a crossroads you may have more than one street and sometimes more than
one lane. So, in the PPF you can more than one structure go through more than one road.
c. You have to imagine that you are putting this crossroads (3 dimensional) into a crevice (other picture).
IV. [S4] Picture of the Pterygopalatine Fossa and Landmarks
a. Here is your infratemporal fossa and here is your PPF and you are looking into the PPF through the
pterygomaxillary fissure.
b. The PPF is bordered by the maxilla bone anteriorly; the sphenoid bone superiorly and posteriorly: the
perpendicular plate of the palatine bone medially.
c. The palatine bone (blue in the diagram is the long arm of the “L”) is shaped like an “L”. You have a
perpendicular plate and a horizontal plate. It is part of your palate so it is considered medial.
d. The blue that you are looking at is the perpendicular plate and is actually the long arm of the “L” and the
horizontal plate will kind of go off medially from here.
e. If you are looking at a real skull you would have the zygomatic process covering all these structures.
f. Roof - greater wing of sphenoid
g. post. wall - lat. pterygoid plate
h. med. wall - perpendicular plate of the palatine.
i. ant. wall - post. surface of the maxilla
j. Ant and post wall converge inferiorly
V. [S5] Real Skull showing location of Pterygopalatine Fossa
a. Here the skull is tilted and you can see the zygomatic process that is partly removed. Here is the sphenoid
bone, pterygoid process, and this region where the red arrow is pointing to is the exit of the PPF.
b. Is a continuation of the Infratemporal fossa
VI. [S6] Pterygopalatine Fossa
a. The yellow oval is the PPF and you have 3 main structures that enter it:
i. The maxillary nerve (V2) of the trigeminal
ii. The maxillary artery
iii. The 3rd part is the pterygopalatine part; the 3rd part is a nerve that is composed of parasympathetic and
sympathetic fibers of the greater and deep petrosal nerve and it is called the nerve of the pterygoid canal or
the Vidian nerve (NOTE: the Vidian nerve is the same thing as the greater and deep petrosal nerve)
b. The maxillary nerve is in the middle cranial fossa to start with as are the greater and deep petrosal nerves.
c. The maxillary artery comes from the infratemporal fossa.
d. The maxillary nerve exits the middle cranial fossa through the foramen rotundum and enters into the PPF.
e. The pterygomaxillary fissure is how the maxillary artery enters the PPF.
f. The nerve of the pterygoid canal comes through the pterygoid canal.
g. So, foramen rotundum, pterygoid canal, and pterygomaxillary fissure are our access routes into the PPF.
h. Greater and deep petrosal nerves form the Nerve of the Pterygoid canal (or Vidian nerve)
VII. [S7] Pterygopalatine Fossa
a. You have one exit into the orbit via the inferior orbital fissure, one exit into the nasal cavity via the
sphenopalatine foramen, and another exit into the oral cavity and that’s the greater palatine canal or just the
palatine canal.
VIII. [S8] Maxillary Artery in the PPF
a. Let’s start with the 3rd part of the maxillary artery.
Neuro: 8:00 - 9:00
Scribe: Brittney Wise
Thursday, March 12, 2009
Proof: Laura Adams
Dr. Bimczok
Pterygopalatine Fossa, Nose and Paranasal Sinuses
Page 2 of 10
b. The maxillary artery enters through the pterygomaxillary fissure. Before this it gives off one branch to the
posterior superior alveolar artery.
c. Then the maxillary artery has branches going to the orbit and face, into oral cavity, and into the nasal cavity.
d. The infraorbital artery leaves through the inferior orbital fissure.
e. The sphenopalatine artery to the nose leaves through the sphenopalatine foramen.
f. The descending palatine artery leaves through the palatine canal.
g. We have one artery that makes the PPF a 2-way street and that is the artery of the pterygoid canal (just a little
branch of it).
h. The pharyngeal branch to the pharynx is present but not shown on this slide.
IX. [S9] Maxillary Artery (part 3) Lateral View
a. This is a head that has been dissected and part of the orbit and zygomatic process has been removed. Here is
a muscle that you have already dissected and is named the lateral pterygoid muscle.
b. This muscle defines the 3 parts of the maxillary artery. Part 2 is in the region of the pterygoid muscle. Part 3 is
in the PPF. You can see the infraorbital artery going into the orbit.
c. The posterior alveolar artery to the teeth is also seen. The middle and anterior come off the infraorbital artery.
d. The 3RD PART OF THE MAXILLARY A. also lies in the pterygopalatine fossa. It has numerous brs., the most
imp. of which are:
1) INFRAORBITAL A. --- In the floor of the orbit this artery gives off the MID. SUP. ALVEOLAR A. to the
premolars and the ANT. SUP. ALVEOLAR A. to the incisors and canine.
2) POST. SUP. ALVEOLAR A. --- Supplies the molar teeth.
3) DESCENDING PALATINE A. --- Not shown.
4) SPHENOPALATINE A. --- Not shown.
X. [S10] Maxillary Artery (part 3) Medial view
a. Here is your nasal septum and your cranial cavity. The pterygoid plate of the sphenoid bone can be seen and
you can also see the pterygopalatine foramen that comes from the PPF into the nasal cavity. Here is also the
sphenopalatine artery that passes through that foramen too.
b. Here is an artery that descends to the palate aka the descending palatine artery. The greater and lesser
palatine arteries branch off of it.
c. And again here is your posterior superior alveolar artery.
d. The other BRS. OF THE 3RD PART OF THE MAXILLARY A. are shown here. The DESCENDING PALATINE
A. splits into two branches. --- The greater and lesser palatine arteries which supply the hard and soft palates
(resp.). The SPHENOPALATINE A. passes through the foramen of the same name to supply the nasal cavity.
Note that the 2nd part of the maxillary a. (in the infratemporal fossa) passes through the pterygomaxillary fissure
to enter the pterygopalatine fossa.
XI. [S11] Maxillary Nerve in the PPF
a. Maxillary nerve enters through the foramen rotundum and it carries on through the inferior orbital fissure as the
infraorbital nerve and the zygomatic nerve.
b. Found in the PPF is the pterygopalatine ganglion which is the parasympathetic ganglion of the head. Some
fibers of the maxillary nerve which are sensory and not parasympathetic at all run through this ganglion, but they
are called pterygopalatine nerves because they connect this main branch of the nerve to the ganglion.
c. Off of this ganglion, the branches to the oral and nasal cavities come off.
d. Through the sphenopalatine foramen, access to the nose, we have posterior superior medial nasal rami and
lateral nasal rami (you can just call them medial and lateral nasal rami.) These innervate the nasal cavity and
the ones on the septum are the medial branches and the lateral ones are on the lateral side of the nasal cavity.
e. The biggest one off the medial rami is the nasopalatine nerve.
f. We also have the greater and lesser palatine nerves running through the palatine canals into the oral cavity.
XII. [S12] Maxillary Nerve (V2) Lateral View
a. Some of the bones have been dissected away to open up the view into the orbit and into the maxillary sinus.
You can still see the mucosa that covers the sinus if the dissection is done well.
b. Here is your trigeminal nerve showing all 3 branches: V1 goes up, the maxillary branch (V2) going through the
foramen rotundum leading into the PPF, and V3 going through the foramen ovale.
c. The 1st branch that comes off V2 is the zygomatic nerve that further branches into the zygomaticofacial and the
zygomaticotemporal nerves. Then you see the infraorbital nerve that runs through the orbit and then through
the infraorbital canal and then comes out onto the face.
d. The 1st branch that comes off of this main branch after the zygomatic nerve is a nerve that innervates the last 2
molars: the posterior superior alveolar nerve (PSA). This is important for dentists because you can anesthetize
this with a local anesthetic to do work on the last 2 molars. Through the inferior orbital fissure you have direct
access into the orbit so there is a risk that some of the anesthetic might leak into part of the orbit and numb
Neuro: 8:00 - 9:00
Scribe: Brittney Wise
Thursday, March 12, 2009
Proof: Laura Adams
Dr. Bimczok
Pterygopalatine Fossa, Nose and Paranasal Sinuses
Page 3 of 10
some of the nerves there when trying to get the PSA. An example of a nerve in the orbit that you could get
would be the abducens nerve which is on the lateral aspect of the orbit.
e. There are also middle and anterior alveolar nerves and they form a plexus with dental and gingival branches.
f. These anterior and middle alveolar nerves run along the wall of the maxillary sinus. So here is the maxillary
sinus and nerve and these branches actually run through the mucosa. This is important clinically because if you
have an infection of the maxillary sinus you can have pain that feels like it’s coming from the maxillary teeth, aka
referred pain. So, the pain is not coming from the teeth but rather a sinus infection because the area is supplied
by the same nerves. (A blue circle appeared later on in the slide to show where you would give the block. This
circle was not on the original power point.)
g. Here is the ganglion with the pterygopalatine nerves running through it.
h. TWO OF THE MOST IMP. CONTENTS OF THE PTERYGOPALATINE FOSSA ARE THE MAXILLARY N. (V2)
& THE PTERYGOPALATINE GANGLION. V2 enters the fossa posteriorly (via f. rotundum) and leaves the
fossa anterosuperiorly (via inf. orbital fissure) to become the infraorbital n. V2 HAS NUMEROUS BRANCHES,
INCLUDING THE FOLLOWING:
1) ZYGOMATIC N. --- This nerve enters the orbit and splits into the ZYGOMATICOTEMPORAL &
ZYGOMATICOFACIAL NN. which are cutaneous to the temple and face.
2) INFRAORBITAL N. --- This is the terminal part of the maxillary n. Before reaching the infraorbital f. to
supply skin of the face, the infraorbital n. gives off the MID. SUP. ALVEOLAR N. to the maxillary
premolars and the ANT. SUP. ALVEOLAR N. to the maxillary incisors and canine. These nerves run
within the bone of the wall of the maxillary sinus and also supply the mucous membrane of the sinus.
3) POST. SUP. ALVEOLAR N. --- This nerve arises directly from V2. It enters the post. sup. alveolar
foramina and canals to supply the maxillary molars and the mucosa of the maxillary sinus.
4) PTERYGOPALATINE NN. --- These short nerves connect V2 with the pterygopalatine ganglion. They
contain primarily sensory fibers (GSA) of V2 which pass through the ganglion WITHOUT SYNAPSE to be
distributed to the pharynx, palate and nasal cavity. The branches of distribution to these areas are
illustrated in the following plate.
 Clinical relevance: infraorbital nerve
 Trigeminal nerve often involved in referred pain
 Pain from abcessed tooth can be described as ocular pain! – overload!
XIII. [S13] Maxillary Nerve (V2) Medial View
a. Looking from this view, again here is our main branch and here is our ganglion. You wouldn’t usually be able to
see that because the palatine canal is covered by a thin bony lamina. You might be able to see the ganglion
because it’s located more or less immediately behind the sphenopalatine foramen.
b. Here is our medial aspect: you can see the ganglion and the nerves descending into the oral cavity and those
are the greater and lesser palatine nerves.
i. Greater palatine nerve supplies the hard palate
ii. Lesser palatine nerve supplies the soft palate posteriorly.
c. Here is the canal that runs through the body of the sphenoid or the base of the pterygoid process and that’s the
nerve of the pterygoid canal formed by the greater petrosal nerve and the deep petrosal nerve.
d. Here again, is the little branch to the pharynx called the pharyngeal branch.
e. In this MEDIAL VIEW of the pterygopalatine ganglion some of the OTHER (INDIRECT) BRANCHES OF V2 can
be seen:
1) PHARYNGEAL BR. --- Sensory to the roof of the pharynx (above the auditory tube).
2) GR. & LSR. PALATINE NN. --- Sensory to the hard and soft palates (resp.).
3) POST. SUP. & POST. INF. LAT. NASAL BRS. --- Sensory to the lateral wall of the nasal cavity.
4) NASOPALATINE N. --- Sensory to the septum (med. wall) of the nasal cavity.
 Also note the PTERYGOID CANAL (containing a nerve of the same name) which passes from
the f. lacerum through the sphenoid to open into the post. wall of the pterygopalatine fossa.
XIV.
[S14] Pterygoplatine ganglion
a. This is the parasympathetic ganglion of the head. The fibers that synapse here are parasympathetic fibers and
you know that there are only 4 cranial nerves that have parasympathetic fibers. The greater petrosal nerve has
fibers from the intermediofacial nerve, cranial nerve #7. Again this is a paramedian section: the orbit and the
nasal cavities have been open.
b. This is your cranial cavity and take note of your internal auditory meatus with the facial nerve and the
vestibulocochlear nerve entering into the petrous bone.
c. The facial nerve has its own sensory ganglion, the geniculate ganglion. In this region, this little nerve comes off
and that’s the greater petrosal nerve and it crosses the area of the foramen of lacerum and foramen ovale and
enters the pterygoid canal. It then synapses in this ganglion here. The parasympathetic fibers then attach
Neuro: 8:00 - 9:00
Scribe: Brittney Wise
Thursday, March 12, 2009
Proof: Laura Adams
Dr. Bimczok
Pterygopalatine Fossa, Nose and Paranasal Sinuses
Page 4 of 10
themselves to all these fibers of the maxillary nerve that we have already talked about and they go into the nasal
cavity to supply the nasal glands because that’s where we need parasympathetic innervation.
d. We also have glands in the palate, the palatine glands, so again the parasympathetic fibers of the greater
petrosal nerve after synapasing at the ganglion attach themselves to the greater and lesser palatine nerve of the
maxillary and innervate the glands of the palate.
e. The most important gland that is innervated by the fibers of the greater petrosal nerve is the lacrimal gland.
f. Why don’t we just call it the greater petrosal nerve (not sure what she’s talking about here)? Because we have
other fibers attaching to it (the structures labeled in green).
i. They are sympathetic fibers that run together with the parasympathetic fibers as the deep petrosal nerve in
the pterygoid canal and they come like any other sympathetic fibers in the head and come off of the
sympathetic ganglion of the neck region and they attach themselves to the internal carotid as a carotid
plexus and actually the internal carotid nerve and goes through the carotid canal.
ii. Then these fibers attach to this greater petrosal nerve and also run with all these fibers. They don’t
innervate the glands directly but they innervate the blood vessels and if you reduce the blood supply to a
gland part of the secretions are reduced.
g. SQ: inaudible
h. ANSWER: The sympathetic fibers travel with the carotid artery. The parasympathetic fibers come off the facial
nerve in the region of the geniculate ganglion.
i. The PTERYGOPALATINE GANGLION is a parasympathetic ganglion. Only presynaptic parasympathetic fibers
from the gr. petrosal br. of VII synapse in this ganglion (GSA fibers from V2 and postsynaptic sympathetic fibers
from the deep petrosal n. pass through the ganglion without synapse). Postsynaptic parasympathetic fibers
supply the gls. of the orbit (lacrimal gl.), roof of the nasopharynx, palate and nasal cavity (secretomotor). (Note:
the postsynaptic sympathetic fibers in the deep petrosal n. are destined mainly for blood vessels). Very strange
XV.
[S15] Parasympathetic and sympathetic fibers to lacrimal gland
a. The Pterygopalatine ganglion supplies the lacrimal gland. The is a lateral view: here is the orbit, maxillary sinus
with these branches to the teeth, and here is the ganglion in the PPF and here is V2. You can’t really see the
greater petrosal nerve.
b. The parasympathetic fibers that get to the lacrimal gland attach themselves to the zygomatic nerve which runs
into the orbit through the inferior orbital fissure and then you have a communicating branch that has fibers that
then attach themselves to the lacrimal nerve that comes off V1. The lacrimal nerve brings those
parasympathetic fibers to the lacrimal gland.
c. SUMMARY: You have parasympathetic fibers from the facial nerve; they synapse in the ganglion, attach
themselves to the zygomatic nerve off of V1, have a communicating branch to the lacrimal nerve off of V1 and
innervate the lacrimal gland.
d. Clinical relevance: infraorbital nerve. Trigeminal nerve often involved in referred pain. Pain from abscessed
tooth can be described as ocular pain! – overload!
XVI.
[S16] Pterygopalatine ganglion
a. Here again is the cartoon showing you the Vidian nerve which enters through the pterygoid canal into the PPF
and then the fibers attach themselves to all these other nerves off V2.
b. She has included a hyperlink on this slide that will take you to the University of Toronto’s website that allows to
you study this material further. (I did not include all of the details she used to describe this website but here is
the link to it: http://brodel.med.utoronto.ca/~dianak/testMRP/fossa.html)
i. SQ: inaudible
ii. ANSWER: No you are thinking parasympathetic fibers. No, the parasympathetic fibers and the
sympathetic fibers attach themselves to V2 and the ones going to the lacrimal gland have a communication
between V2 and V1.
iii. SQ: inaudible
iv. ANSWER: So the question is what fibers travel with V1 and which fibers run with V2. Basically all the
fibers coming through the pterygoid canal which are the parasympathetic and sympathetic fibers, attach to
fibers of V2, but we need to get some fibers to the lacrimal gland and there is no branch of V2 going to the
lacrimal gland, V1 does this. That is why you have this communicating branch that brings the fibers that
have attached to V2 out to V1. They just travel together.
XVII. [S17] The Nose
a. How do we get into the nose via the PPF? We have got to take one of these exit routes, but which one would
you take to the nose? Answer: the sphenopalatine foramen.
b. Functions:
i. Breathing
ii. smell (olfaction)
Neuro: 8:00 - 9:00
Scribe: Brittney Wise
Thursday, March 12, 2009
Proof: Laura Adams
Dr. Bimczok
Pterygopalatine Fossa, Nose and Paranasal Sinuses
Page 5 of 10
iii. warm inspired air (the air we breathe is warmed up and humidified in the nose; about 1 liter of fluid a day is
added to the air we breathe in)
iv. humidify inspired air (90%)
v. trap foreign objects (hair in the vestibule of the nose and a thick mucus layer trap these objects)
vi. immune defense (Secretory IgA)
vii. speech (nasal sounding consonants like “m” and “n”)
XVIII. [S18] Skeleton of the external nose
a. She skipped this one but I don’t know that it was intentional.
b. The EXTERNAL NOSE has both a BONY & CARTILAGINOUS FRAMEWORK. The bones are the nasal,
frontal and maxilla (frontal pr.). The cartilages are the septal, lat. nasal and gr. alar.
XIX.
[S19] Muscles, nerves and arteries of the external nose (muscles)
a. Muscles of facial expression are innervated by CN #7. We have 4 muscles that attach to the nose:
i. Procerus muscle
ii. Depressor septi muscle
iii. Nasalis muscle (the most important one … this shows the transverse portion)
iv. Muscular levator labii superoris alaque nasi
b. Various mm. of ext. nose (mm. of facial expression, innervated by VII).
c. Cutaneous innervation by brs. of V1 and V2.
d. Vessels by branches of ophthalmic and facial aa.
XX.
[S20] Muscles, nerves and arteries of the external nose (nerves)
a. We just discussed the infraorbital nerve which is a branch of V2.
b. The superior posterior part of the nose is supplied by nerves off of V1 (specifically the nasociliary branch of V1).
These include the infratrochlear and the external nasal nerve off the anterior ethmoidal nerve.
c. We have combined innervation of the nose by V1 and V2.
XXI.
[S21] Muscles, nerves and arteries of the external nose (arteries)
a. The arteries get even more complicated:
i. infraorbital artery supplies the lateral part of the nose off of the maxillary artery that we just looked at
ii. coming off the opthalamic artery are the dorsal nasal artery and the external nasal artery which is a branch
of the anterior ethmoidal artery (these actually come off the ICA).
iii. a 3rd artery that helps supply the lateral nose and that is the lateral nasal artery off of the facial artery, which
is an earlier branch of the ECA
XXII.
[S22] External Nose
a. Anatomists tend to think of the nose as being analogous to an iceberg. There are a ton of structures
underneath the nose, aka the majority of the iceberg is below water.
XXIII. [S23] Nasal Cavity
a. Here you can see the external nose and the nasal cavity which is where the functional part of the nose is
located. You should know the 3 nasal concha: Superior, Middle, Inferior
i. Air actually passes through these 3 concha through the superior, middle, and inferior nasal meatus.
b. You can see your nasal cavity, nasal vestibule (covered by normal skin), and the nasal part of the pharynx. The
connection between the nasal cavity and the nasopharynx is called the choanae.
XXIV. [S24] Functional regions of the nose
a. She told us that the sense of smell was located in the nose, but it’s a very minor portion located in the superior
part of the nose around the superior nasal concha and around the superior part of the nasal septum. There are
only about 1.3cm of mucosa that are associated with olfactory mucosa.
b. The remaining region is called the respiratory region. In the vestibules you have normal skin that’s kind of the
same skin as you have on the face.
c. The respiratory region is covered by respiratory epithelium.
d. The nasal cavity consists of three regions:
A. Nasal vestibule is a small dilated space just internal to the naris that is lined with skin and contains
hairs (filter air)
B. Respiratory region is the largest part of the nasal cavity. It has a rich neurovascular supply, and is
lined by respiratory epithelium composed mainly of ciliated and mucous cells (thus air is warmed and
moistened as is passes over this epithelium).
C. Olfactory region is small. It is lined by olfactory epithelium which contains olfactory neurons, the
axons of which constitute the olfactory n. (I) (The sense of smell in man is poor compared to animals such
as dogs)
XXV. [S25] Bones of the Nasal Cavity
a. This shows the medial aspect of the nasal cavity. On the left the nasal septum has been removed. On the right
the nasal septum is still in place.
Neuro: 8:00 - 9:00
Scribe: Brittney Wise
Thursday, March 12, 2009
Proof: Laura Adams
Dr. Bimczok
Pterygopalatine Fossa, Nose and Paranasal Sinuses
Page 6 of 10
b. The PPF is behind the sphenoid bone. The blue is the “L” shaped palatine bone with your perpendicular plate
and the horizontal plate forming the palate. The rest of the palate is formed by the maxillary bone. You also
have the sphenoid bone with the body and the pterygoid processes.
c. The superior portion is formed by the ethmoid bones and you can see that all of this sort of pinkish (I think she
meant purple). The superior and middle nasal concha are extensions of the ethmoid bone.
d. The inferior concha is separate bone and that’s why it has a different color.
e. There is a small part of the lacrimal bone that forms part of the nasal cavity.
f. The nasal bone and the frontal bone are also 2 other bones that make up the nasal cavity.
g. If we look at the nasal septum you can see the ethmoid bone, the nasal bone, and you also see the
cartilaginous part of the septum (this is not bone!)
h. There is also a bone here that is unpaired and that is the vomer (green in the diagram). You can see an
indentation of this bone and this is where the nasopalatine nerve runs (one of the medial nasal branches of the
maxillary nerve).
XXVI. [S26] Bones of the Nasal Cavity
a. The bones get a little more complicated because when you remove the middle nasal concha you see a couple
more structures that you need to identify. They are important for the connections of the paranasal sinuses with
the nose.
b. This is a hoop shaped process. A hoop shaped process in anatomy is called an uncinate process, same as on
the vertebra of the neck.
c. The ethmoidal bulla is bulbous shaped and is an outgrowth of the ethmoid bone. Between this bulla and the
uncinate process we have something that’s kind of shaped like a ½ moon and that is the semilunar hiatus.
d. In this dissection the MID. NASAL CONCHA HAS BEEN CUT AWAY TO EXPOSE SOME DEEPER
STRUCTURES. The ETHMOIDAL BULLA is a bulge produced by the mid. ethmoidal air cells. Inferior to the
bullla is a curved ridge of bone called the UNCINATE PR. Between the bulla and uncinate pr. is a curved
groove, the SEMILUNAR HIATUS, which receives the openings of some of the paranasal sinuses.
XXVII. [S27] Nerves of the Nasal Cavity
a. Again, the sense of smell is located in the superior part of the nasal cavity and we have a number of small fibers
off of the olfactory bulb transversing the cribiform plate of the ethmoid bone and they supply this olfactory region
up here.
b. As in the external nose you have fibers off of V2 which enter the nose through the sphenopalatine foramen and
supply the mucosa of the posterior part of the nasal cavity. You have lateral and medial branches that run along
the septum. The most important medial branch, the one that forms this indentation in the vomer, is the
nasopalatine nerve. It actually extends into the oral cavity as well through the incisive canal.
c. Again, the more superior anterior portion of the nasal cavity is supplied by fibers off of V1 off the anterior
ethmoidal nerve.
d. A black line showed up on the screen to differentiate the areas innervated by V1 and V2.
e. The NERVE SUPPLY OF THE NASAL CAVITY is well illustrated in this plate. The NERVES OF GENERAL
SENSATION (GSA) ARE BRS. OF V1 & V2. The ANT. ETHMOIDAL N. (V1) supplies the anterosuperior part of
both the septum and lat. wall. The remainder of the septum is supplied by the NASOPALATINE N. (V2), while
the remainder of the lat. wall is by the POST. SUP. & POST. INF. LAT. NASAL BRS. OF V2.
XXVIII. [S28] Arteries of the Nasal Cavity
a. Most of these are the same as the nerves.
i. You have the anterior ethmoidal arteries with some external nasal branches on the outside
ii. You have the opthalamic artery which is a branch of the ICA
iii. Here again is the sphenopalatine foramen where the sphenopalatine artery enters the nasal cavity from the
pterygopalatine fossa which has all these branches
iv. If you look at the septum you can see that the branches of the ethmoidal artery and the sphenopalatine
artery anastimose in this region. You have a number of arteries here. This is a region where a lot of nose
bleeds occur because it’s very vascular. It is clinically important and has a specific name which is the
“Kiesselbach area”.
b. SQ: Why do nose bleeds happen?
c. ANSWER: Sometimes they can be mechanical or maybe differences in local blood pressure, I really am not
sure.
d. The Kiesselbach area is still located in the cartilaginous part of the nose so it is flexible and if you have a small
child with a nose bleed you can pinch the nose here and compress the blood vessels and stop the bleeding.
e. The ARTERIAL SUPPLY to the nasal cavity is from the SPHENOPALATINE A. and the ANT. & POST.
ETHMOIDAL AA. The sphenopalatine a. enters the nasal cavity through the sphenopalatine f. and divides into
brs. for both the septum and lat. wall. (The ant. and post. ethmoidal aa. do the same.)
Neuro: 8:00 - 9:00
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Thursday, March 12, 2009
Proof: Laura Adams
Dr. Bimczok
Pterygopalatine Fossa, Nose and Paranasal Sinuses
Page 7 of 10
f. In the REGION OF THE ANTEROINFERIOR PART OF THE SEPTUM the sphenopalatine a. anastomoses with
the septal br. of the sup. labial a. and with the gr. palatine a. This is the region where EPISTAXIS
(NOSEBLEED) USUALLY OCCURS. Epistaxis may be the result of trauma, infections or hypertension . If it is
so severe that it cannot be controlled by the usual means ligation of the ext. carotid a. may be required.
XXIX. [S29] Veins of the Nasal Cavity
a. You don’t have to know the veins in dental you just need to remember that you have the anterior and posterior
ethmoid veins and they drain into the cavernous sinus. You know that there is always a risk of infection,
thrombosis, and damage to all these structures running through it.
b. The sphenopalatine vein drains through the pterygoid plexus in the infratemporal fossa.
c. The pterygoplexus is also connected to the cavernous sinus (via anastomosis) so here is another location for a
risk of infection that can lead into the cavernous sinus.
d. Veins draining the nasal cavity generally follow the arteries:
a. Veins draining anterior region of nasal cavity drain to facial v.
b. Veins draining posterior region of nasal cavity drain to pterygoid plexus.
c. Veins draining superior region of nasal cavity drain to sup. ophthalmic v. (which in turn goes to
cavernous sinus).
d. In some individuals, an additional vein (emissary v.) passes superiorly through the f. caecum to join
the anterior end of superior saggital sinus
XXX. [S30] Paranasal Sinuses
a. Mucosa-lined outgrowths of the nasal cavity; this sounds complex but this is exactly what happens during
development; the mucosa buds into the bones of the head and this creates air-filled spaces.
b. One important function seems to just be reduction of bone mass. This reduction makes our heads lighter.
c. The picture on the slide is of an elephant’s head and all of the spongy area is where you would find the
paranasal sinuses.
d. Resonating chambers (voice); this is a function seen in humans
e. NO-production (immune functions)
i. the mucosa can make NO which has an immune function and reduces the risk of infection in the sinus
f. Orbit is surrounded by sinuses. Roof of maxillary sinus – orbital plate – only 0.5 – 1 mm. Need to include info
on lacrimal canal!
XXXI. [S31] Paranasal Sinuses
a. There are 4 paired paranasal sinuses that are names after the bones of where they are located so there are a
total of 8 altogether.
i. The largest one is the maxillary sinus located in the maxilla.
ii. The frontal sinus in the frontal bone.
iii. The ethmoidal sinuses (cells) in the ethmoid bone. There are several smaller spaces here.
iv. More posteriorly we have the sphenoid sinus in the body of the sphenoid bone.
b.
The PARANASAL SINUSES are AIR-FILLED SPACES WITHIN THE FRONTAL, SPHENOID, ETHMOID
AND MAXILLARY BONES. All of the sinuses are paired (even the sphenoid) and all open into the nasal cavity
because they develop as outgrowths of that cavity. The paranasal sinuses are lined with mucous membranes
that contain cilia. They vary considerably in size between individuals and may be asymetrical in the same
person. The ethmoid sinus consists of a series of small cells (3-18) rather than a single space.
The FUNCTIONS which have been ascribed to the paranasal sinuses are numerous. Among these are:
1) act as resonating chambers for the voice 2) lighten the skull 3) bring about an equal distribution of weight in
the head (this could explain their asymetry in some individuals) 4) add moisture (in the form of mucus) to the
nasal cavity and 5) produce nitric oxide! (In a recent study it was shown that exhaled nitric oxide in humans
originates mainly from the sinuses, and it was speculated that this contributes to the control of bacteria and to
the functioning of the epithelial cilia). The morphology of the frontal sinus is also useful in forensic medicine
because it can be used to identify skeletal remains.
DRAINAGE of the sinuses is by ciliary action and perhaps by suction during blowing of the nose.
Sometimes the sinuses become infected (sinusitis) and do not drain properly.
XXXII. [S32] Chart (Empty; see slide 36 for complete chart)
a. The most important thing clinically is the spatial relationships, so what is the sinus next to. Sinus infections are
frequent, so if the sinus is infected it might damage neighboring structures.
b. The drainage site is where the sinus is actually connected to the nasal cavity.
XXXIII. [S33] Sphenoid sinus and ethmoidal cells
a. If you just look at the picture it might be obvious as to what structures you might damage. Let’s start with the
sphenoid sinus in the body of the sphenoid bone.
b. Do you have any ideas what the sphenoid sinus is close to? Answer: the pons, basilar artery, and optic
nerve/chiasm, ICA, anterior cranial cavity (medially we have the orbit).
Neuro: 8:00 - 9:00
Scribe: Brittney Wise
Thursday, March 12, 2009
Proof: Laura Adams
Dr. Bimczok
Pterygopalatine Fossa, Nose and Paranasal Sinuses
Page 8 of 10
c. Same for the ethmoidal cells you have the cranial cavity, nasal cavity, and the orbit is located laterally.
d. Sphenoid sinus is related to pituitary gland superiorly, nasopharynx inferiorly, nasal cavity anteriorly (note
opening in its anterior wall leading to sphenoethmoidal recess), and the pons posteriorly. Pituitary gland can be
approached surgically through nasal cavity and sphenoid sinus.
e. Nerve and blood supply to sinus is via pharyngeal n. (V2) and posterior ethmoidal n. (V1), and corresponding
arteries.
XXXIV. [S34] Frontal and Maxillary Sinus
a. It’s easier to identify surrounding structures for the frontal sinus. There’s the cranial cavity and the orbit.
b. The maxillary sinus is the most frequently infected and it’s close to the orbit and close to the roots of the teeth./
She told us about the problem re: referred pain that some of the nerves that run through the mucosa of the sinus
can feel pain if the sinus is infected and you might think that it’s pain in the teeth.
c. Of course there is risk that the infection from an infected tooth can spread and go into the maxillary sinus.
Sometimes this lamina between the maxillary sinus and the teeth is really thin and sometimes you only have
mucosa and not really a bony layer. So, if you extract a maxillary tooth with not so straight root you can create a
fistula into the maxillary sinus and then you have a great risk for increased infection.
d. You can also get referred pain from the maxillary sinus into the orbit and you can also have infection of the orbit
through the sinus infection.
e.
The MAXILLARY SINUS is the largest (15 mL) of the paranasal sinuses and IS THE MOST IMP. SINUS
FOR THE PRACTICE OF DENTISTRY. Note its RELATIONSHIPS: 1) FACE (anteriorly) 2)
INFRATEMPORAL & PTERYGOPALATINE FOSSAE (posteriorly) 3) ORBIT (superiorly) and *4) ALVEOLAR
PR. OF MAXILLA (WITH ROOTS OF MOLAR TEETH --- AND SOMETIMES PREMOLARS AND CANINE AS
WELL) (inferiorly). The relationships of the maxillary sinus to the roots of the teeth is imp. because tooth
infections can spread into the sinus. Extractions may also result in breaking off the root tips which may become
lodged in the sinus.
The OPENING OF THE MAXILLARY SINUS into the mid. meatus is HIGH on the med. wall of the sinus -- a poor location in terms of drainage. Because of this fact the maxillary sinus is the sinus most frequently
infected. Sometimes MAXILLARY SINUSITIS IS ACCOMPANIED BY TOOTHACHE. This is because the
mucosa lining of the sinus is innervated by the three superior alveolar nerves --- the same nerves that innervate
the maxillary teeth. This is an example of referred pain. In some cases of sinusitis it may be necessay to
surgically widen the opening into the nasal cavity. The approach used is through the thin bone of the canine
fossa. The three superior alveolar aa. supply blood to the sinus.
XXXV. [S35] Chart (with Relationships column filled in)
a. Keep in mind infection routes, but also especially through the sphenoid sinus (this is what she said but I can’t
make sense of it). There can be surgical approaches to various structures. So, you can go through the sinuses
and get to a lot of these closely related structures surgically.
XXXVI. [S36] Chart (with Relationships and Drainage site columns filled in)
a. NOTE: I didn’t include statements that she read directly off the chart below.
b. Drainage site are where outgrowths from the nasal cavity started in embryonic or just normal development.
c. The frontal sinus drains into the middle nasal meatus as do most of the other sinuses. The maxillary sinus
drains into the semilunar hiatus, which is still in the middle nasal meatus. Remember it’s that part between the
bulla and the uncinate process.
d. The middle cells drain right on this bulla.
e. The sphenoid sinus is located posteriorly and superiorly so it actually drains superior to the superior nasal
concha which is the sphenoethmoidal recess.
Sinus
Relationships
Drainage site
Nerve Supply
Frontal
Orbit; anterior cranial fossa
Middle nasal meatus
Supraorbital nerve and
artery
Maxillary
Nasal cavity, orbit, maxillary
Semilunar hiatus (in
Anterior, middle, and
teeth
middle nasal meatus)
posterior superior alveolar
nerves and arteries
Ethmoidal (cells)
Anterior
Nasal cavity, orbit, cranial fossa Semilunar hiatus
Anterior and posterior
ethmoidal nerves and
Middle
Ethmoidal bulla
arteries (of nasocilliary
Posterior
Superior nasal meatus
nerves and arteries
Sphenoid
Pons, basilar artery, optic
Sphenoethmoidal recess
Lateral posterior superior
chiasm and nerves, pituitary,
nasal nerve, posterior
nasal cavity, nasopharynx,
ethmoidal nerve and artery
cavernous sinus
Neuro: 8:00 - 9:00
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Dr. Bimczok
Pterygopalatine Fossa, Nose and Paranasal Sinuses
Scribe: Brittney Wise
Proof: Laura Adams
Page 9 of 10
XXXVII. [S37] Access to Paranasal Sinuses (medial section of the nasal cavity)
a. All the nasal concha have been sectioned away. Here is your pharynx, your sphenoid sinus, and this has a
small connection to the area above the superior nasal concha.
b. The posterior ethmoidal cells open in the superior nasal meatus and you can also see your middle nasal meatus
with the bulla and the opening of the middle ethmoid cells. You can also see the semilunar hiatus. The
uncinate process would border it anteriorly and this is where the maxillary sinus and the anterior ethmoid cells
drain. You have the opening of the frontal sinus still in the middle nasal meatus but more anteriorly.
c. In the inferior nasal meatus we have the drainage of the nasal lacrimal duct.
d. The OPENINGS OF THE PARANASAL SINUSES INTO THE NASAL CAVITY are shown (note that the mid.
and inf. conchae have been removed). The SPHENOID SINUS opens through its ant. wall into the
sphenoethmoidal recess. The FRONTAL SINUS opens into the ant. part of the mid. meatus. The MAXILLARY
SINUS opens into the post. part of the semilunar hiatus. The ETHMOIDAL CELLS are divided into ant., mid.
and post. groups. The ANT. GROUP opens into the ant. part of the semilunar hiatus, the MID. GROUP onto the
ethmoidal bulla and the POST. GROUP into the sup. meatus. The NASOLACRIMAL DUCT (from the lacrimal
sac) empties into the ant. part of the inf. meatus.
XXXVIII.
[S38] Maxillary Sinus
a. This is a frontal section of the head showing the orbit, nasal cavity, and your maxillary sinus which is sort of
triangular shaped. It is also showing you the inferior and middle nasal concha. So you can identify your middle
nasal meatus here and the drainage site is up a little bit.
b. It looks a little bit unpractical to have a closed room in the head that drains on the superior aspect of that cavity.
This is a reason why you get a buildup of fluid in this maxillary sinus and you can imagine how this would affect
the roots of the teeth.
c. So, what would you do for a sinus infection? You can imagine that you could drill a hole in the bottom and that it
would all drain, which might seem more practical. That’s not actually what we do today. Anatomy is more
logical than you might think.
d. This is what the mucosal lining of the maxillary sinus in the nose looks like. The respiratory epithelial cells are
the epithelia that cover the surface of the sinus. They have tiny hair-like cilia on top and those cilia can move
the mucus along. This is what happens in all of your airways. This system is very efficient.
e. The way this works in the maxillary sinus is all directed so the cilia direct the mucus flow toward this opening.
f. So, what you do today for a sinus infection is you remove parts of the uncinate process and the middle concha
and just enlarge this opening to enable thick mucus to flow out more easily and to get more air into the sinus. If
you have more air the risk of getting an anaerobic infection is reduced.
g. Clinic: Sinusitis can easily penetrate into the orbit – can lead to infection of orbital connective tissue termed
orbital cellulitis.
The MAXILLARY SINUS is the largest of the paranasal sinuses and IS THE MOST IMP. SINUS FOR
THE PRACTICE OF DENTISTRY. Note its RELATIONSHIPS: 1) FACE (anteriorly) 2) INFRATEMPORAL &
PTERYGOPALATINE FOSSAE (posteriorly) 3) ORBIT (superiorly) and *4) ALVEOLAR PR. OF MAXILLA
(WITH ROOTS OF MOLAR TEETH --- AND SOMETIMES PREMOLARS AND CANINE AS WELL) (inferiorly).
The relationships of the maxillary sinus to the roots of the teeth is imp. because tooth infections can spread into
the sinus. Extractions may also result in breaking off the root tips which may become lodged in the sinus.
The OPENING OF THE MAXILLARY SINUS into the mid. meatus is HIGH on the med. wall of the sinus -- a poor location in terms of drainage. Because of this fact the maxillary sinus is the sinus most frequently
infected. Sometimes MAXILLARY SINUSITIS IS ACCOMPANIED BY TOOTHACHE. This is because the
mucosa lining of the sinus is innervated by the three superior alveolar nerves --- the same nerves that innervate
the maxillary teeth. This is an example of referred pain. In some cases of sinusitis it may be necessay to
surgically widen the opening into the nasal cavity. The approach used is through the thin bone of the canine
fossa. The three superior alveolar aa. supply blood to the sinus.
XXXIX. [S39] Chart (same as in slide 36)
a. Refer to chart above (it’s filled in from what was shown in class)
b. Remember when we dissected the orbit we looked at the supraorbital nerve that actually went along the frontal
sinus, so that supplies the frontal sinus.
c. The superior alveolar artery supplies all the teeth of the maxilla so the anterior, middle, and posterior alveolar
nerves supply the maxillary sinus. Remember the referred pain from these nerves.
d. For the ethmoid cells it’s the ethmoidal nerves and arteries that come off the nasociliary nerve.
e. The sphenoid sinus is located posteriorly so it’s supplied by the lateral posterior, superior nasal nerves. That is
just basically the lateral branches that come out of the sphenoethmoid foramen and the posterior ethmoidal
nerve and artery.
Neuro: 8:00 - 9:00
Scribe: Brittney Wise
Thursday, March 12, 2009
Proof: Laura Adams
Dr. Bimczok
Pterygopalatine Fossa, Nose and Paranasal Sinuses
Page 10 of 10
XL. [S40-43] Dissection
a. This is an inferior view of the hard palate. You are going to remove the mucosa of the hard palate and try to find
the greater and lesser palatine nerve that run along it. They come out of the palatine canal or palatine foramen
which is opposite the 3rd molar (the last molar).
b. We are then going to do a bit more dissection of the pharynx. Last time we looked at the auditory tube and the
muscles that life and stretch the soft palate (the levator palatini and the tensor palatini which is more lateral.
c. We are then going to look at the salpingopharyngial muscle, the palatopharyngeal muscle, and the palatoglossal
muscle. Between the palatoglossal and the palatopharyngeal muscle is where the palatine tonsil is located. If
you remove the tonisil you can see the glossopharyngeal nerve (CN #9) and some arteries and veins.
d. For tomorrow, for all these nasal nerves, we are going to look at the nasal septum. Again, remove the mucosa
and try and find the nasopalatine nerve. Also look at the different bones. You should also try to locate the
opening of the sphenopalatine foramen.
e. Of course, we want to see the drainage sites of the paranasal sinuses. They are mostly in the middle nasal
meatus but they are hidden by the middle nasal concha. You have to remove the middle nasal concha so that
you can see the bulla and the semilunar hiatus and find all these openings. You should also try and put a probe
into the sphenoethmoidal foramen into the sphenoid sinus.
f. We can also have a look at the pterygopalatine ganglion. At this step you will have removed all of the concha
and you should remove the mucosa that’s in the posterior part of the nasal cavity and you should be able to see
the greater and lesser palatine running through a canal that’s covered by a thin bony layer. Again, here you can
see the sphenopalatine foramen with the ganglion. So, you can put a probe through that canal and break off the
lamina that covers it and then pry apart the nerves and the sphenopalatine artery.
g. You should also try and find the nerve of the pterygoid canal coming off that ganglion.
h. The EXTERNAL NOSE has both a BONY & CARTILAGINOUS FRAMEWORK. The bones are the nasal,
frontal and maxilla (frontal pr.). The cartilages are the septal, lat. nasal and gr. alar.
XLI.
[S44] Picture
[end 59:22 min]