Download Transcripts/2_6 8

S1: Gross Anatomy : 8:00-9:00
Scribe: Andrew Treece
Friday, February 6, 2009
Proof: Sunita Jagani
Dr. G. Salter
Superficial Face, Eyelids, Lacrimal Apparatus & Scalp
Page 1 of 6
Dr. Salter kind of jumped around from picture to picture but I tried to keep up with it the best I could. Most of it was all
included in the lecture slides as well.
Figures on Board: You have got to know the trigeminal nerve and facial nerve.
Left Diagram: Facial nerve enters the internal auditory meatus, it comes into the skull 19mm long before it divides into a
branch anteriorly, the greater petrosal nerve, which carries a lot of parasympathetic fibers that eventually reach the
lacrimal gland. The main portion of the facial nerve then extends and forms a part of the middle ear. If you have otitis
media, infection of the middle ear, a common facial nerve may be involved. This facial nerve comes out of the
stylomastoid foramen, when this comes out of the foramen it looks like the second facial nerve picture drawn on the
board. Again, the facial nerve also sends out a branch called the greater petrosal nerve anterior. The picture on the left
is of the facial nerve lying in the temporal bone. It gives off two branches in the middle ear, a branch to the smallest
muscle in the body the stapedius muscle that goes to the stapes one of the smallest bones in the body. If this muscle
contracts it keeps the stapes from going back and forth like a piston and it dampens sound. The second branch in the
middle ear is called the chorda tympani nerve, and whenever you see the palprebral think eyelid, when you see tympanic
think middle ear, so the chorda tympani is a nerve in the middle ear that looks like a chord. It has a couple of functional
components in it meaning that fibers go to two places, the blue are the sensory taste fibers to the anterior two thirds of the
tongue. The purple fibers are parasympathetic preganglion fibers that extend down to the submandibular ganglion which
is close to the submandibular gland. Postganglionic fibers then go from the ganglion to the submandibular gland and then
to the sublingual gland later on.
Mid Left Diagram: This is the facial nerve coming out of the stylomastoid foramen. It gives off branches, and when you
think of the facial nerve coming out onto the face it does so in a series of five branches. These branches supply the
muscles of facial expression, every one of them. Remember: To Zanzibar By Motor Car.
T=temporal branches (sometimes called the frontal branch because they go to the frontalis muscle)
Z=zygomatic (he wrote zanzibar but it’s zygomatic) mainly going to the orbicularis oculi muscle to close the eye
B = buccal, which means cheek (malar means cheek also) and these run with the parotid duct
M= mandibular, which runs along the margin of the mandible and supplies the inferior oral area
C= cervical, supplies the platysma muscle in the neck
Trigeminal nerve diagrams (the two on the right): Trigeminal nerve comes off the pons, and has a lot of sensory fibers
in it. Those have their cell bodies in the trigeminal ganglion. The fibers initially leading into the trigeminal ganglion where
the cell bodies are located most of those fibers are sensory so they are called central processes of the cell bodies.
Peripheral processes from this single cell body, these are sensory fibers coming in from wherever V2 goes, V1 goes, V3
goes. Cell body’s sitting right in the trigeminal ganglion, middle cranial fossa, then the sensory fibers comprise the
sensory root of the trigeminal nerve. There is also another bunch of fibers running with the sensory fibers, they are motor
fibers to eight skeletal muscles, the muscles of mastication and that is all you need to know right now. The fibers drawn
do not go with V1 or V2, they are strictly sensory. The V1 and V2 fibers are the peripheral processes of the single axons
that come down and have their cell body in the trigeminal ganglion. Then other sensory fibers run from this trigeminal
ganglion down and comprise most of the fibers in V3, but again these motor fibers sitting in the pons come out and form
the motor root of the trigeminal nerve. These motor root fibers come out and pass only with V3, and as they pass to the
periphery they supply those eight different muscles (4 of mastication, 4 others).
I. Introduction [S1]
II. Bones of the Face [S2]
III. Skull (Anterior View) [S3]
a. Note that plate numbers are on most slides with figures from Netter’s Atlas.
b. Here is the big frontal bone, which has a supraorbital notch (or foramen) where the supraorbital artery, vein, and
nerve pass. The nerve coming out of there sends sensory branches to a space inside the frontal bone called
the frontal sinus. When you press on the supraorbital nerve, a branch of V1, you transiently depolarize the
electrical impulses within that nerve and you are relieved of pain stemming from a headache for a while,
although it comes back.
c. The maxilla is the upper jaw. There is a foramen here called the infraorbital foramen where a branch of V2
comes out. Then if you follow the line from the supraorbital foramen down it would intersect the infraorbital
foramen and then intersect the mental foramen. There is a terminal cutaneous branch of V3 comes out of the
mental foramen. (Three foramen, three branches of Cranial Nerve V)
d. The maxilla is hollow because of a maxillary air sinus that lies within it.
e. You need to know where the lacrimal bone is.
S1: Gross Anatomy : 8:00-9:00
Scribe: Andrew Treece
Friday, February 6, 2009
Proof: Sunita Jagani
Dr. G. Salter
Superficial Face, Eyelids, Lacrimal Apparatus & Scalp
Page 2 of 6
f. The nasal bones are easy to break because they are really thin.
g. There is a frontal process of the maxilla extending superiorly toward the frontal bone. There is a crest on that
called the anterior lacrimal crest, and there is also a posterior lacrimal crest, and these form the boundaries of
the lacrimal fossa where the lacrimal sac sits. You can feel anterior lacrimal crest on yourself.
h. The zygomatic bone is the most frequently fractured bone in the face.
i. In the mandible you should know ramus, body, mental tubercle, mental protuberance, mental foramen (mental
means chin)
j. Note that there is an alveolar arch of the maxilla which has pockets in it that resemble the alveoli of the lungs.
The same is true for the mandible, an alveolar process that has the mandibular teeth sitting in sockets.
IV. Skull (Lateral View) [S4]
a. You need to know everything here about the mandible. The junction of the ramus and the body is called the
angle. You should know the condyloid process that has a head and neck on it, and it has a coronoid process
and between the two is the mandibular notch which can be used to access the inner portion of the face called
the infratemporal fossa.
b. There are five parts of the temporal bone: the mastoid process, the styloid process, a tympanic portion, a
squamous portion, and where the middle and inner ear lie is the petrous portion.
c. Squamous is flat, mastoid looks like a breast, tympanic plate, styloid process, and again in the inside is the
petrous bone.
d. The portion that extends towards the zygomatic bone is called the zygomatic process, and a small portion is
considered the temporal portion of the zygomatic bone. Regardless, this is called the zygomatic arch
sometimes called the zygoma, easily fractured and is the most easily fractured region, not necessarily the whole
zygomatic bone but the arch.
e. The lacrimal bone sits between the eye and nose, and the frontal process of the maxilla has the anterior lacrimal
crest while the lacrimal bone has the posterior crest. Between the two crests sits the lacrimal sac and the
nasolacrimal duct drains down into the nose after that.
f. Two alveolar arches one for the maxilla and one for the mandible.
V. Mandible (Medial View) [S5]
a. If we look on the internal aspect of the lower jaw bone we have along this condyloid process a little neck that
has a depression called the pterygoid fovea which means depression where the pterygoid muscle attaches.
b. The lingula is a little spike of bone that denotes the location of the mandibular foramen. You can palpate this to
know where to inject the inferior alveolar nerve.
c. There is a mylohyoid line, mylo referring to molar and the line extends posterior to the third molar, it begins there
if you will and then extends anteriorly. The mylohyoid muscle is there, and you have one on the other side.
d. On either side of that line you have a fossa. The upper fossa is for the sublingual gland that lies in the oral
cavity because this muscle right in here is a continuous sheet of muscle dividing the oral cavity from the neck.
e. Superior to that is the sublingual fossa for the sublingual gland lying in the oral cavity, below that is the
submandibular fossa for the submandibular gland to reside in the neck.
VI. Plate 15, Mandible of Older Person [S6]
a. If we look at an older person’s bone, it shows a mandible and how this mandible bone resorbs.
b. There are no teeth here, and if you want to put on a plate of teeth for the lower jaw for the mandible that plate
may fit over that hole, the mental foramen, which is sensory. So a plate there may cause a lot of pain.
VII. Maxillary Sinus (Relationships) [S7]
a. This is the maxilla with a hole in it, the maxillary sinus or space.
b. Some of you are getting confused with the perinasal spaces and dural venous sinus. The perinasal sinuses are
air sinus that have grown out from the nose whereas the dural venous sinuses are vascular and contain blood.
c. Notice the alveolar processes of the teeth extending up into the alveolar process for the maxilla. We will talk
about horrible pain dealing with the trigeminal nerve that may cause people to commit suicide, trigeminal
neuralgia. They usually come into the dentist’s office complaining of pain in the upper teeth, and that is V2
which supplies sensory fibers to the upper teeth so when they think they have a dental problem it is actually a
problem with the trigeminal ganglion.
VIII. Picture of Bones of Face [S8]
a. The maxilla lies inferior to the orbit, posteriorly there is an infratemporal fossa, and anteriorly is the facial surface
of the maxilla.
b. We will talk about septal cartilages and other nasal cartilages later.
IX. Muscles of Face [S10]
X. Muscles of Facial Expression[S10]
a. If you compromise the temporal branch of the facial nerve that supplies the frontalis muscle, you can’t raise the
frontalis muscle until those fibers regenerate.
b. Zygomaticus major allows you to smile.
S1: Gross Anatomy : 8:00-9:00
Scribe: Andrew Treece
Friday, February 6, 2009
Proof: Sunita Jagani
Dr. G. Salter
Superficial Face, Eyelids, Lacrimal Apparatus & Scalp
Page 3 of 6
c. Don’t worry about the Rizorius muscle.
d. Corrugator supercilii Dr. Tubbs likes to find.
e. Nasalis muscle wrinkles up the nose.
f. Procerus muscle probably won’t be asked.
XI. Muscles of Facial Expression Derived from Pharyngeal Arch 2 [S11]
a. All of the muscles of facial expression come from the second pharyngeal arch. As the muscle layer is laid down
there is a single layer of muscles, and depending upon how much we use the muscles of facial expression they
will hypertrophy accordingly. If the cadavers have been in a nursing home, there may not have been a need to
use the facial muscles to cry, smile, whatever, so they may have atrophied and not hypertrophied.
b. They all come from the second pharyngeal arch, and depending on which portion of the face they reach, they
can contract and cause movement and increase in size.
XII. Muscles of Facial Expression (side view) [S12]
a. The facial nerve fibers supply all of these muscles, and the most important fibers are the Zygomatic, Buccal, and
Mandibular branches. Who cares if you can’t raise your frontalis muscle, but closing your eye is important and
brought about by the zygomatic branches. The eye will dry out and you’ll get an ulcerated cornea.
b. The muscles of the nose are pretty important, and the muscles of the upper and lower lip are extremely
important and they are supplied by branches of the buccal branch and mandibular branch.
c. So the ones right in the middle are the most important.
d. Study these muscles on your own.
e. The orbicularis oculi muscles supply the eye. There is a part on the bone that is called the orbital portion and a
part on the eyelid that is called the palpebral portion, palpebral means eyelid.
f. The orbicularis oris (oral cavity) muscle receives the insertion of a lot of muscles that bring about the opening
and closing of the oral cavity.
g. Look for the smile muscle, the zygomaticus major, and there may or may not be a minor muscle associated with
it coming from the zygomatic bone and extending toward the oral cavity.
h. The platysma extends superiorly toward the oral cavity.
i. There is an elevator and depressor of the oral cavity, and an elevator and depressor of the angle of the mouth
when you smile the angle of your mouth turns up. So the zygomaticus muscle and the levator anguli oris
muscle elevates it. The levator labii superioris, labii means lip, so it elevates the lip. There is a depressor labii
inferioris also.
j. All of these muscles are innervated from facial nerve, and usually from the deep aspect of the muscle.
XIII. Muscles of Face, Scalp, Anterior View [S13]
a. There’s another picture to look at for review.
XIV.
Buccinator Muscle [S14]
a. This forms the major component of the cheek. If you take the tip of your tongue and stick it into your cheek, the
major component between the tip of your tongue and your cheek is the buccinator muscle. Buccal means cheek.
b. It is the muscle that trumpeters use, and is a muscle of facial expression.
c. The parotid duct pierces the muscle to enter the oral cavity. The parotid gland along with the submandibular and
sublingual glands are the three major salivary glands that produce secretions which help digestion to take place.
These glands all have openings into the oral cavity.
XV. Function of Buccinator Muscle [S15]
a. Now we said the buccinator muscle is a muscle of facial expression, but if you have a piece of food lying in
between the teeth while chewing, to keep that food in the oral cavity you contract that buccinator muscle and it
forces the food into the oral cavity proper. Sometimes if you have facial nerve palsy the food will collect out in
the vestibule of the cheek because that muscle doesn’t compress the cheek and force it back into the oral
cavity.
b. It is considered an accessory muscle of mastication.
XVI.
Superficial Arteries and veins of the face and scalp [S16]
a. This is a great slide that isn’t labeled, but it’s pretty much what we were supposed to do in lab.
b. The facial vein and artery parallel one another and extend up toward the medial angle of the eye, the medial
canthus, and the facial artery ends there and the vein begins there. Notice that the artery is anterior (a=anterior)
to the vein.
c. Remember the parotid gland is around the ear, with the duct crossing right across the anterior portion masseter
muscle and penetrates the buccal muscle.
d. There is also a superficial temporal artery and vein that should be visible in lab.
e. The frontalis muscle has a companion called the occipitalis muscle, which is also a muscle of facial expression,
and although it isn’t on the face it’s connected to the frontalis muscle which lies on the face. There is a specific
branch off of the facial nerve supplying the occipitalis muscle.
XVII. Nerves of Face [S17]
S1: Gross Anatomy : 8:00-9:00
Scribe: Andrew Treece
Friday, February 6, 2009
Proof: Sunita Jagani
Dr. G. Salter
Superficial Face, Eyelids, Lacrimal Apparatus & Scalp
Page 4 of 6
XVIII. Facial Nerve (VII) exits cranial cavity via internal auditory meatus [S18]
a. Facial nerve passes through the internal auditory canal or meatus along with the eighth nerve
XIX.
VII Emerges from Stylomastoid foramen[S19]
a. Most of its fibers that come out of the stylomastoid foramen give out the TZBMC branches and other branches
as well.
XX. Facial Nerve Branches in Parotid Gland [S20]
a. This is a depiction of the parotid gland, and the facial nerve passes through it and divides into its temporal
branches and its zygomatic branches, both of which are said to cross the zygomatic arch and extend superiorly.
b. The main function of the temporal branch is to supply the frontalis muscles.
c. The zygomatic branches supply mostly the orbicularis oculi.
d. The buccal branches surround the parotid duct. Notice most of these facial nerve fibers run horizontally,
whereas trigeminal nerve fibers run vertically.
e. The marginal mandibular branch runs along the margin of the mandible and it always runs superficial to the
artery and vein. If this nerve were cut, the depressor anguli oris, the depressor labii inferioris would be
sacrificed, and this could also happen by a cancer of the submandibular gland.
f. The cervical branch goes to the platysma muscle.
g. A little branch in the facial nerve, the posterior auricular nerve, goes back to supply more muscles of facial
expression and of the ears, some people can move their ears. Then there is the little branch that goes back to
the occipitalis muscle.
XXI.
Course of VII in Facial Canal [S21]
a. Here the facial nerve enters the internal auditory meatus, it hits a dead end where the geniculate ganglion lies
which is a sensory ganglion for the facial nerve. It is at this bend that there is a branch called the greater
petrosal nerve that comes off.
b. The facial nerve continues through the middle ear as it lies in the facial canal giving off a nerve to the stapedius
and the chorda tympani nerve.
c. Then the facial nerve comes out onto the face to divide into those muscles of facial expression branches and
the other small branches.
XXII. Bell’s Palsy [S22]
a. Now what if you have a viral infection of the facial nerve within the facial canal? Then you have Bell’s Palsy.
b. This is not just traumatic injury, this is specific pathology involving the facial nerve as it lies in the facial canal,
and it gives one an ipsilateral paralysis of the muscles of facial expression. It may give other signs. What if the
viral infection affects an area just inferior to the internal auditory meatus S[22], the nerve has already been given
off to the lacrimal gland so it is spared, but these branches downstream to the stapedius is affected, the chorda
tympani nerve taste fibers and submandibular gland fibers are affected, and of course the muscles of facial
expression are affected.
c. So if you lose the nerve to the stapedius which dampens sound, everything will sound loud. If the greater
petrosal nerve is affected, you will lose lacrimation function
d. If you affect the greater petrosal nerve then you would affect lacrimation.
e. Main idea: everything downstream is affected
XXIII. Trigeminal Nerve (V) [S23]
a. Trigeminal nerve you have to know everything about it!
b. The trigeminal ganglion contains GSA, general somatic afferent, cell bodies are located right here. That is
complement to the dorsal root ganglion or spinal ganglion of spinal nerves, just sensory fibers only.
c. All of these sensory fibers that comprise all three branches of the trigeminal nerve have their cell bodies here,
V1, V2, and V3.
XXIV. Roots of V [S24]
a. Now this is the trigeminal ganglion. This shows the posterior cranial fossa, the sixth nerve, internal auditory
meatus, and the seventh and eighth nerves.
b. This shows your posterior clinoid process and your mandibular fossa. Dr. Zehren is likely to put a tag in there
and say what causes this depression. That would be your trigeminal ganglion causing the depression.
c. There is a segregation between the sensory fibers and motor fibers (motor root should be found in lab), so pain
in the region of the trigeminal nerve, usually involving V2, is called trigeminal neuralgia, or called tick doulourex
that causes ticks and pain.
d. Pain can be so bad that they can go in and work on it, but if you cut the sensory root you may lose all sensory
info, but they have gotten specific enough to cut only specific nerve bundles.
XXV.
Vertex – Ear – Chin Line [S25]
a. This is the dermatome of the face realizing that you have dorsal rami branches (greater occipital nerve etc),
ventral rami branches (greater auricular nerve), then you have the trigeminal nerve supplying the face.
b. The slide shows the boundaries of the dermatomes.
S1: Gross Anatomy : 8:00-9:00
Scribe: Andrew Treece
Friday, February 6, 2009
Proof: Sunita Jagani
Dr. G. Salter
Superficial Face, Eyelids, Lacrimal Apparatus & Scalp
Page 5 of 6
XXVI. Cutaneous Nerves of Head and Neck [S26]
a. You have to know this!!! He just read these off.
XXVII. Vessels of Face [S27]
XXVIII. Facial Artery [S28]
a. Remember the common carotid splits into an internal and external carotid, and the internal supplies the brain
and external branch supplies the external structures via eight branches.
b. Facial artery, superficial temporal artery, transverse facial artery, two posterior branches off of the external
carotid (occipital artery, posterior auricular artery) are all important.
XXIX. Arterial Supply to the Face [S29]
a. On the face there is anastamoses from the branches of the internal carotid via the ophthalmic artery and the
external indirectly from some of its branches. This is arterial supply to the face, the red represents supply from
the external carotid, the superficial temporal artery, facial artery, and then you see supraorbital, supratrochlear
branches off of the ophthalmic artery which comes off of the internal carotid.
b. So there is anastomoses between the internal and external carotid.
XXX. Facial Vein [S30]
a. There are veins in the face which collectively drain into the external jugular or the internal jugular usually, but
some of these may drain deeply into the dural venous sinuses bringing about inflammation, thrombophlebitis,
meningitis, all kinds of things from infection entering the face and passing deeply and eventually entering the
cavernous sinus for one.
XXXI. Routes fro Spread of Infection from Facial V. into Cranial Cavity [S31]
a. Here is the angular vein and the facial vein. Facial vein begins in the angle of the eye as the angular vein which
connects via the superior ophthalmic vein and eventually reaching into the cavernous sinus.
b. The angular vein and facial vein can pass deeply via the superior ophthalmic vein or the deep facial vein.
c. The infection can be carried via those branches into the pterygoid plexus of veins and eventually reach the
cavernous sinus bringing about potential thrombophlebitis so blood passes slowly through the sinus.
XXXII. Dural Venous Sinuses [S32]
a. This brings about potential thrombophlebitis. This is manifested by ophthalmoplegia, it paralyzes the eye so all
of the extrinsic eye muscles don’t work. If you cannot move your eye you will have diplopia, where the eyes are
looking in different direction.
XXXIII. External Nose [S33]
XXXIV. Michael Jackson: Cartilaginous framework [S34]
a. There are five major cartilages: septal which is enlarged to form the lateral cartilages and the two major alar
cartilages that look like a wing.
b. You have your nostral, and rhinoplasty typically involves augmentation of the septal cartilages etc.
c. Rhinoplasty again involving the septal cartilages.
XXXV. Nose (Skeleton) [S35]
a. Five main cartilages: lateral cartilages which are lateral expansions of the septal cartilages and two major alar
cartilages. They are major because there are two minor ones. The major alar cartilage has a medial leg or crus
and a lateral crus, but out on the lateral side of the nostril is nothing but fat with no cartilage.
XXXVI. Plate 36 [S36]
(ended first session at 51:53) returned after a five minute break
XXXVII. Eyelids & Lacrimal Apparatus [S37]
XXXVIII.
Eyelids (Sagittal Section) [S38]
a. There are five layers to the eyelid:
1. Skin
2. Subskin, subcu where the cilia (eyelashes are located) and very little fat
3. Muscle layer with palpebral portion of the orbicularis oculi
4. Dense connective tissue plate called the tarsal plate and the fascia associated with it. The medial
and lateral palpebral ligaments are thickenings of this fourth tarsal fascial layer
5. Conjunctiva, thin and transparent that covers the inside of the lid and the eye. If you flip it inside
out you may see some of the tarsal (meibomian) glands in vertical streaks. These are oil glands
that secrete oil down onto the eye so the water doesn’t come onto the face.
b. Same is true for the lower lid.
c. The orbital septum is a continuation of the tarsal fascial layer (4th) which divides the superficial region from the
deep region. This has to do with a lot of infections.
XXXIX. Tarsofascial Layer of Eyelids [S39]
a. If we remove the skin and subcu and remove the palpebral portion of the muscle we are on the fourth layer so
this is the tarsofascial plane. It thickens medially and laterally as the medial and lateral palpebral ligaments. It
is continuous with the orbital septum superiorly that extends up and connects with the periorbita and periostium.
S1: Gross Anatomy : 8:00-9:00
Scribe: Andrew Treece
Friday, February 6, 2009
Proof: Sunita Jagani
Dr. G. Salter
Superficial Face, Eyelids, Lacrimal Apparatus & Scalp
Page 6 of 6
b. Have been known to tag these structures.
c. You can see the anterior lacrimal crest, posterior to which is the lacrimal sac, but notice the medial palpebral
ligament has a strong attachment to that anterior lacrimal crest. Surgeons operating on the lacrimal sac that is
plugged up and makes the tears run onto the face will go in and canulate that region.
d. The beginning of the facial vein, the angular vein, begins here also in the medial canthus of the eye.
XL. Lacrimal Apparatus [S40]
a. There is a secretory portion, a delivery portion, and there is a drainage part.
b. The secretory portion is the lacrimal gland that secretes about 90% of the tears. There are minor glands that
secrete the other 10%, but don’t worry about that.
c. The tears come down and the orbicularis oculi muscle contracts a little from lateral to medial in blinking to push
the tears medially across the eyelid like a windshield wiper and this is the delivery mechanism.
d. The drainage portion includes the plica semulinaris (semi-lunar fold of the conjunctiva), the caruncle which is just
a mound of modified skin. On either side of these are holes called the lacrimal punctum which reside on the
lacrimal papilla and these holes receive the tears. These lead to canaliculi (small canal) which carry the tears to
the lacrimal sac and then the nasolacrimal duct takes it down into the nose.
XLI.
Plate 82 [S41]
a. In your dissection, you remove the medial palpebral ligament and look for the lacrimal sac.
b. The lacrimal sac drains tears into the inferior meatus of the nose via the nasolacrimal duct.
c. Sometimes the duct can be occluded and tears can spill over onto the face, and this is called epiphora.
XLII.
Innervation of Lacrimal Gland [S42]
a. Now how is the lacrimal gland innervated?
b. The facial nerve comes off of the brain stem, the greater petrosal nerve has preganglionic parasympathetic
fibers running in it, the presynaptic fibers go to a parasympathetic ganglion called the pterygopaltine ganglion,
synapse, and then postsynaptic fibers in order to get to the lacrimal gland hitch a ride on V2 which then hitches
a ride on with V1.
XLIII. Plate 45, 4th Ed. [43]
a. Trigeminal ganglion with the maxillary going through the foramen rotundum.
b. The zygomatic nerve divides into a branch that comes out right on the zygomatic bone called the
zygomaticofacial foramen and nerve. The zygomaticotemporal nerve comes out of the temporal region and
supplies the hairless portion of skin there.
c. Notice there is a connection in the zygomaticotemporal and the lacrimal nerve. This communicating branch
carries parasympathetic fibers from the pterygopaltine ganglion which come in and synapse, the postganglionic
fibers run up to V2, they run in the zygomatic nerve and connect to V1 via the lacrimal branch which carries
secretory fibers to the lacrimal gland.
d. Understand that you can produce a dry eye by destruction of the facial nerve because of several things. It could
be because of destroying the innervation of the orbicularis oculi or destroying the innervation of the lacrimal
gland.
XLIV. Scalp [S44]
XLV. S.C.A.L.P. [S45]
a. Skin
b. Connective Tissue which is dense where the main blood vessels and nerves lie
c. Aponeurosis which is between the frontalis muscle and occipitalis muscle which is called the occipitofrontal
aponeurosis. It is a wide flat tendon between the two muscles.
d. Loose connective tissue, the danger zone because infection here can drain via the emissary veins into the
dural sinuses
e. Pericranium
XLVI. Nerves and Arteries of Scalp [S46]
a. So the major blood vessels and nerves lie in the second layer.
b. Supratrochlear and supraorbital coming from the ophthalmic, superficial temporal which is the last branch from
the external carotid, posterior auricular from the external carotid, occipital artery.
c. The nerves are V1 (supraorbital and supratrochlear), V2 (zygomaticotemporal), V3 (auriculotemporal)
d. V1,V2, and V3 all help to supply the scalp.
e. Ventral rami (lesser occipital), dorsal rami (greater occipital and occipitalic tertius) All of those lie in that second
layer, and notice how they all anastamose with each other, so if you hit your head you may bleed profusely
because they are all connected.
(end time 15:10)