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Anatomy Second Semester Oral Quiz Review1/29/2013 5:21:00 AM
1) Demonstrate the organization of the three layers of the
pericardial sac and explain their role in the occurrence of pericardial
tamponade.
The pericardial sac begins externally with a tough fibrous layer of dense
connective tissue. Internal to that is the serous parietal pericardium, and,
like the lung, there is a visceral pericardium attached directly to the organ
parenchyme, that here, is the myocardium.
Pericardial tamponade is an acute type of pericardial effusion. Due to the
tough outer layer of the pericardial sac, there is a finite space that fluid may
accumulate in, and while it does so, puts a great deal of pressure on the
ventricles, reducing stroke volume. The cause of the effusion can be
myocardial rupture, pericarditis, trauma, neoplasm, and cardiac surgery.
Pressure is relieved by pericardiocentesis (needle inserted from the skin by
ultrasound guidance)
2) Demonstrate the transverse and oblique sinuses of the
pericardium, describing their borders (arterial and venous) and
explain their use in cardiac surgery.
After the pericardial sac has been opened anteriorly, a finger can be passed
through the transverse pericardial sinus posterior to the aorta and
pulmonary trunk. The transverse pericardial sinus is between the venous
and arterial mesocardia, namely, the ascending aorta and pulmonary artery
cranio-ventrally and the superior vena cava dorsally.
The transverse pericardial sinus is especially important to cardiac surgeons.
By passing a surgical clamp or placing a ligature around these vessels,
inserting the tubes of a coronary bypass machine, and then tightening the
ligature, surgeons can stop or divert the circulation of blood in these large
arteries while performing cardiac surgery.
The oblique pericardial sinus lies posterior to the heart (dorsal) and is
bounded
 Anteriorly by serous pericardium of the left atrium
 Posteriorly by the parietal pericardium of the pericardial sac
 Superiorly and laterally by the reflection of serous pericardium
around the four pulmonary veins, SVC & IVC
Lift the apex of the heart and place fingers posterior to the heart to identify
the oblique pericardial sinus. This space is utilized during cardiac surgery to
manually massage and manipulate the heart.
3) Demonstrate the four borders of the heart seen in the anterior
view (inferior, superior, left or right pulmonary) and describe the
structures composing each border.
Right border (from superior to inferior)
 SVC
 Right atrium
 IVC
Left border (from superior to inferior)
 Arch of the aorta (aortic knob on film)
 Pulmonary trunk (knob)
 Left auricle
 Left ventricle
4) Demonstrate the four surfaces of the heart (anterior, posterior,
left & right lateral, inferior & superior) ….[that’s six for those
counting] and describe the structures composing each surface.
Superior: where the great vessels are located
Inferior (floor): directed downward and dorsally, is formed by both ventricles
and rests on the central tendon
Right Lateral: Right atrium, ventricle and vena cavae
Left Lateral: Left auricle, atrium and ventricle
Posterior: Left atrium, vena cavae, pulmonary veins, coronary sinus
Anterior: The apex of the heart, formed by both ventricles, and the left
auricle and right atrium compose the anterior aspect of the heart.
5) Demonstrate the components present in the right atrium and
right ventricle and explain the clinical aspects of right sided failure.
The right atrium receives venous, oxygen-poor blood, from the systemic
circulation via the superior vena cava (SVC), inferior vena cava (IVC), and
(posteriorly) the coronary sinus. The pectinate muscles extend from the
crista terminalis (vertical muscular ridge on the internal surface of the
anterior right atrial wall.) The crista terminalis separates the rough
pectinate surface from the smooth surface posterior, termed the sinus
venarum. The fossa ovale is also visible, a region of the interatrial
septum, which, in the patient’s embryonic life, served as a right-to-left
shunt, known as the foramen ovale. The smooth interior portion of the
anterior right atrial wall is what remains of the sinus venarum.
The right ventricle receives from blood from the right atrium via the
tricuspid valve. The chordae tendineae are ligaments that connect each
cusp to the papillary muscles, closing each cusp when the papillary
muscles are contracting. The valve has a septal, anterior and posterior
valve. Tracking the anterior papillary muscle inferiorly, one can locate the
muscular moderator band (aka septomarginal trabeculae) and follow it to
the ventricular septum. The moderator band carries the right bundle
branch from the AV node. The trabeculae carnea is the term for the
musculature of the right ventricular wall. The conus arteriosus is the
narrowing, smooth walled portion of the ventricle located left and superiorly,
leading to the pulmonary valve, which also has three cusps; anterior, right
and left cusps.
When the right ventricle begins to lose efficiency (losing ejection fraction)
Common clinical symptoms of right-sided heart failure:
 Dyspnea
 Peripheral edema
 Jugular vein distension (JVD)
 Nocturia
 Hepatomegaly
Common causes of right-sided heart failure:
 Coronary artery disease (CAD)
 Left-sided heart failure
 COPD or chronic bronchitis / emphysema alone
 Congestive Heart Failure (CHF)
 Pulmonary embolism (PE)
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Valvular disease / damage / defect
Anemia (associated)
Hyperthyroidism
6) Demonstrate the components present in the left atrium and left
ventricle and explain the clinical findings in left sided failure.
The left atrium receives oxygen-rich blood from the pulmonary venous
system (2 veins per lung). These pulmonary veins dump into the posterior
region of the left atrium. Blood passes from the left atrium to the left
ventricle via the mitral valve (aka bicuspid valve).
The left ventricle receives oxygen-rich blood and is responsible for pumping
that into the systemic circulation. With a much thicker myocardium than the
right ventricle, the left also has two papillary muscles, (one per mitral cusp).
Blood is ejected through the aortic (semilunar) valve into the ascending
aorta. From the ascending aorta, you can see the 3 sac-like depressions
called aortic sinuses. From these sinuses you can find the coronary artery
and vein branch points.
Left-sided heart failure is associated with these symptoms & findings:
 Increased work to breath
 Rales or crackles upon auscultation (lung bases)
 Pulmonary edema
 Pulmonary effusion
 Cyanosis
 Cough, frothy
 Hemoptysis
 Needs to elevate head
 Decreased urine production
 Fatigue, weakness
 Paraoxysmal nocturnal dyspnea
 Weight gain
 Laterally displaced heart apex beat
 Gallop rhythm
Common causes of left-sided heart failure:

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MI
Myocarditis
High blood pressure
Valvular damage, defect, disease
Hypothryroidism
7) Demonstrate the course of the great vessels in and out of the
heart and explain the two ‘crosses’ present in the heart.
Identify
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
them on your own heart:
Pulmonary veins
Pulmonary arteries
Ascending aorta
Inferior & Superior Vena Cavae
The two crosses of the great vessels are (1) between the pulmonary veins
and the vena cavae and (2) aorta and the pulmonary trunk (45° from floor)
(Thanks reader)
8) Describe and identify the sites of auscultation of the cardiac
sounds on your partner.
A(ortic) region: Between 2nd & 3rd intercostal spaces, immediately lateral to
sternum (RUSB)
P(ulmonary) region: Left 2nd intercostal space, immediately lateral to
T(ricuspid) region:
sternum (LUSB)
to 6th intercostal spaces, at lower left sternal border
4th
(LLSB)
M(itral) region: between 5th and 6th intercostal spaces on the left
mid-clavicular line
Note!
The below image shows the tricuspid region too far to the right.
Please note the auscultation of the tricuspid is on the left border, not
right.
Week 25
1/29/2013 5:21:00 AM
1.) Demonstrate the major coronary arteries (see pictures below @
#2) and discuss the mechanism for generating systole in the
coronary system
During systole, the contraction of the ventricular musculature compresses
and occludes the coronary vasculature. At the moment of contraction, blood
is pushes into the venous system to the coronary sinus. Also, some blood is
pushed back into the epicardial vessels (superficial, large portions of
coronary arteries), which act as capacitors.
2.) Describe the cardiac veins and demonstrate their presence where
possible on the heart
3.) Describe the conductile system of the heart and demonstrate its
components wherever possible on the heart.
Beginning with the sinoatrial node, which is located on the lateroposterior
aspect of the right atrium. (may be visible on exterior surface). The SA
node is the pacemaker of the heart and demonstrates phase 4
depolarization, a.k.a. automaticity. A given depolarization travels next to
the atrioventricular node, located between the atria & ventricles. The AV
node shows the slowest conduction velocity, which permits complete
ventricular filling before the contraction of the myocardium occurs.
The impulse then travels through the bundle of His, which runs along the
interventricular septum as right and left bundle branches. At the apex of the
heart, the bundle branches lead to the Purkinje fiber system. The Purkinje
fibers provide electrical conduction to the ventricles, transmitting a paced
interval.
4.) Describe the sympathetic innervation of the heart and
demonstrate its components wherever possible on the heart and
great vessels.
(See answer for #5 below)
5.) Describe the sympathetic innervation of the heart and
demonstrate its components wherever possible on the heart and
great vessels.
Sympathetic Innervation
 Preganglionic: T1 to T4(T5)
 Postganglionic: Cervical ganglia and cardiac sympathetic nerves
Parasympathetic Innervation
 Preganglionic: vagal nuclei and vagal cardiac nerves
 Postganglionic: Cardiac ganglia and cardiac plexus
Related anatomy
 The cardiac plexus is divided into two regions
o Superficial


Posterior to arch of aorta, anterior to pulmonary trunk
Formed by superior cardiac branch of left sympathetic
trunk and lower superior cervical cardiac branch of the
left vagus nerve
o Deep
 Anterior to tracheal bifurcation, posterior to arch of
aorta, superior to pulmonary arterial split
 Formed by cardiac nerves by the cervical ganglia of
sympathetic trunk and the cardiac branches of the vagal


and recurrent laryngeal nerves
 Splits into left and right branches
If possible, locate the vagus, recurrent laryngeal, sympathetic trunk
(T1-T4/5) & splanchnic nerves
Note, the left vagus nerve innervates the AV node & the right vagus
innervates the SA node
6.) Demonstrate the approximate location of the four cardiac valves
on a PA chest film and describe the auscultation points for each
valve.
As you can see below: (not a PA chest film) but helpful
 Follow the anterior 3rd rib on the right (aortic valve)
 Follow the anterior 3rd rib of the left (pulmonary valve)
 Follow the anterior 5th rib on the right (tricuspid valve)
 Follow the anterior 4th rib on the left (mitral/bicuspid valve)
The locations for auscultation are more clearly seen in the photo, the valve
locations are a bit difficult to see, but they’re there.
Week 26
1/29/2013 5:21:00 AM
Demonstrate the branches of the ophthalmic division of the
trigeminal nerve and describe the nerve fiber components or specific
function of those branches
Ophthalmic nerve fibers carried
 Somatic afferent (GSA)
o Sensation to the
 Upper face
 Ciliary body
 Cornea
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
Iris
Portions of nasal mucosa
Sphenoidal sinus
Frontal sinus
Tentorium cerebelli
Posterior dura mater
Posterior area of falx cerebri
Branches of the ophthalmic division of the trigeminal nerve


Nasociliary nerve
o Branch to sensory root of ciliary ganglion
 Sensation from eye ball components
o Posterior ethmoidal nerve
 Sensation from posterior ethmoidal air cells
o Long ciliary nerve
 Carry sympathetic fibers from stellate ganglion to the
dilator pupillae muscle
 Sensation from sclera, choroid, iris, cornea
o Infratrochlear nerve
 Sensation from skin just medial to palpebral fissure
o Anterior ethmoidal nerve
 Sensation from anterior ethmoidal air cells
Frontal nerve
o Supratrochlear nerve
 Sensation from
 midline, inferior forehead


 conjunctiva
 skin of upper eyelid
o Supraorbital nerve
 Sensation from
 Frontal sinus
 Conjunctiva
 Skin of the forehead (2 branches)
Lacrimal nerve
o Sensation to the lacrimal gland & conjunctiva
Recurrent meningeal branch to tentorium, falx
Demonstrate the branches of the maxillary division of the trigeminal
nerve and describe the nerve fiber components or specific function
of those branches
Maxillary nerve fibers carried
 Somatic afferent (GSA)
o Sensation to
 Maxillary

 Nasal cavities
 Sinuses
 Palate
 Mid-face
Visceral efferent pathway (GVE)
o Lacrimal nerve (V1) conveys parasympathetic fibers from CN
VII originating by the zygomatic branch of V2 from the
pterygopalatine ganglion
Branches of the maxillary division of the trigeminal nerve
Pathway
 Passes from trigeminal ganglion through the cavernous sinus and
exits via foramen rotundum
 Crosses pterygopalatine fossa
 Enters orbit at infraorbital fissure
 Traverses the infraorbital groove and emerges on the face via the
infraorbital foramen
In the cranium
 Middle meningeal nerve
From pterygopalatine fossa
 Infraorbital nerve
 Zygomatic nerve
 Nasal branches
 Superior alveolar nerves (posterior superior, middle superior)
 Palatine nerves (greater & lesser palatine nerves)
 Pharyngeal nerve
In the infraorbital fissure
 Anterior superior alveolar nerve
 Infraorbital nerve
On the face
 Inferior palpebral nerve
 Superior labial nerve
Demonstrate the branches of the mandibular division of the
trigeminal describe the nerve fiber components or specific functions
of those branches
Mandibular nerve fibers carried (via foramen ovale)
 Special visceral efferent (BE)
o To muscles of mastication
 Visceral efferent (GVE)
o Lingual nerve to chorda tympani
Branches of mandibular division of trigeminal
 From main trunk

o Meningeal branch (enters cranium via foramen spinosum)
 Sensory to the dura mater
o Medial pterygoid nerve (motor)
 Tensor tympani
 Tensor veli palatine
Anterior division
o Masseteric nerve (motor)
o Deep temporal nerves (ant & post) motor
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
o Buccal (sensory!!) nerve
o Lateral pterygoid nerve (motor)
Posterior division
o Auriculotemporal nerve (sensory)
 Parasympathetic fibers from CN IX to the parotid gland
o Lingual nerve (sensory)
 parasympathetic fibers from CN VII
o Inferior alveolar nerve (sensory)
Motor to
o Mylohyoid muscle
o Anterior digastic muscle
Demonstrate the muscles of mastication, including their specific
action, attachments, innervation and suggest muscle strength tests
to determine function
Masseter muscle
 Action: elevation and protraction of the mandible
 Superficial head
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

Origin: Zygomatic process of maxilla, anterior 2/3 zygomatic
arch
Insertion: Angle and lower half of ramus of mandible
Deep head
Origin: posterior 1/3 of zygomatic arch
Insertion: upper half of ramus, coronoid process of mandible
Innervation: Masseteric Nerve, from V3
Strength testing: Ask patient to clench their teeth, and then open
mouth, while palpating the masseter muscle
Temporalis muscle
 Action: elevation and retraction of the mandible
 Origin: temporal lines of parietal bone, temporal fossa
 Insertion: runs medial to zygoma to the coronoid process of
Mandible
 Innervation: deep temporal nerves, from V3
 Strength testing: Ask patient to clench teeth, open mouth, while
palpating the temporalis muscle (via temples)
Lateral pterygoid muscle
 Actions:
o bilateral - depression & protrusion of mandible
o unilateral – contralateral excursion of mandible
 Superior head
Origin: infratemporal surface/crest of greater wing of
sphenoid bone
Insertion: Articular disc, TMJ capsule
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
Inferior head
Origin: lateral surface of lateral pterygoid plate
Insertion: neck of mandibular condyle
Innervation: lateral pterygoid nerve, from V3
Strength testing: ask patient to open their mouth against
resistance, then ask to move mandible laterally
against resistance
Medial pterygoid muscle
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Actions:
o Bilateral – elevation of mandible
o Unilateral – assist ‘laterals’ in contralateral excursion
Superficial head
Origin: Maxillary tuberosity
Deep head (much larger)
Origin: medial surface of lateral pterygoid plate
Common Insertion: Medial angle of the mandible
Innervation: nerve to medial pterygoid, via V3
Strength testing: ask patient to open mouth and clench teeth while
palpatng the masseteric region. (Resistive lateral
excursion tests both pterygoids).
Demonstrate the branches of the facial nerve and describe the nerve
fiber components or specific function of those branches
Facial nerve fibers carried




Special visceral efferent (BE)
o Facial nucleus
 Facial expression musculature
 Stylohyoid muscle
 Posterior belly of digastric muscle
 Stapedius muscle
Visceral efferent (GVE)
o Superior salivatory nucleus
 Synapse at pterygopalatine and submandibular ganglion
 Lacrimal gland
 Submandibular gland
 Glands of nasal mucosa & both palates
 Sublingual glands
 Small salivary glands of the tongue dorsum
o Also, visceral efferents form the parotid plexus
Special visceral afferent
o Nucleus of the solitary tract (NST)
 Chorda tympani, carrying gustatory fibers from tongue
 (taste)
Somatic afferent (GSA)
o Sensation from
 Auricle
 Skin of auditory canal
 Outer tympanic membrane
o Via CN VII to the principal sensory nucleus of CN V
Branching inside petrous portion of temporal bone
 Greater petrosal nerve (GVE)

Stapedial nerve (BE)
o To stapedius muscle
 Chorda tympani (GVE, SA)
Branching outside the cranium
 Posterior auricular branch
 Branch to digastric & stylohyoid
 Temporal branch*
 Zygomatic branch*
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

Buccal branch*
Marginal branch*
Cervical branch*
*superficial branches to muscles of facial expression
Below:picture shows the labeling of each branch of the superficial facial
nerve, post-parotid.
Demonstrate two dissection approaches to the pterygopalatine
ganglion, including which structures must be removed or displaces
in order to see the walls of the pterygopalatine fossa
Note: Only going from my experience with my donor on this answer
1.) Anterior approach
 Reflect the masseter muscle, tendon of temporalis
 Remove the superior portion of the mandible, from the angle to the
TMJ

Examine the nerve and vascular components present between the
medial and lateral pterygoid muscles
2.) Posterior approach
 Must have ‘face-off’ cut performed on your cadaver
o Posterior to trachea, anterior to styloid processes of skull and
longus musculature
 Position the face ‘face-down’ and approach the ganglion from the
posterior
 The medial pterygoids are appreciable, as is the maxillary artery
and its divisions. The ganglion is located between the two
pterygoid muscles, so carefully pick or reflect the medial pterygoid
to reveal the nerves
Week 27
1/29/2013 5:21:00 AM
1.) Demonstrate the pterygopalatine ganglion and associated nerves
and discuss the outward clinical manifestations of pterygopalatine
ganglion failure and pterygopalatine ganglion hyperfunction
(sphenopalatine neuralgia). Contrast with submandibular ganglion
and otic ganglion failure.
Pterygopalatine ganglion branches
 Nasopalatine
 Greater palatine
 Lesser palatine

Pharyngeal branch of maxillary nerve
Failure
o Numb canines, lateral incisors, molars
o Numb hard palate
o Difficulty swallowing
Sphenopalatine Neuralgia
 Ice cream headache
 Also, cluster headache patterns have been described by
hyperfunction of this ganglion
Otic ganglion failure
 The otic ganglion supplies parasympathetic innervation to the
parotid gland
 Failure here would manifest itself through a lack of enzymatic saliva
supplied to the oral cavity
Submandibular ganglion failure
 Failure to produce saliva (produces nearly 70% of saliva to mouth)
2.) Demonstrate the muscles of the tongue and describe their
innervation (nerves and specific fibers carried).
Extrinsic (BE nerves)
 Genioglossus muscle
o Hypoglossal nerve
o From mandible
 Hyoglossus muscle
o Hypoglossal nerve
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
Intrinsic
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o From hyoid bone
Styloglossus muscle
o Hypoglossal nerve
o From styloid process
Palatoglossus muscle
o Pharyngeal branch of vagus nerve
o From palatine aponeurosis
(All Hypoglossal nerve, BE fibers)
Superior longitudinal muscle
o Along superior surface of tongue
Inferior longitudinal muscle
o Lines the sides of tongue
Verticalis muscle
o Middle of tongue, joins both longitudinal muscles
Transversus muscle
o Divides the middle of the tongue
3.) Describe the act of swallowing, paying attention to voluntary
acts vs involuntary components, including which muscles are used
during use phase and their innervation.
A.) Oral Phase
This phase is voluntary whose sole purpose is to prepare a bolus from the
food placed in the mouth, aside from parasympathetic salivation
 Moistening
o Parasympathetic (chorda tympani: CN VII, lesser petrosal: CN
IX)
 Mastication
o Voluntary motor (V3) and buccinators (VII)
 Trough formation
o Intrinsic muscles force bolus to posterior tongue (XII)
 Movement of bolus to posterior oropharynx
o Once the bolus reaches the palatoglossal arch, as propelled
by intrinsic and extrinsic tongue muscles (XII), the
pharyngeal phase (involuntary, takes over)
B. Pharyngeal Phase (involuntary reflex)
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
Closure of the nasopharynx
o Soft palate is tensed, (tensor palatini, (V3))
o Soft palate is elevated, (levator palatini, (XI, X)
o Approximation of pharynx towards posterior soft palate
 Palatopharyngeus m (IX, X)
 Superior constrictor (IX, X)
Pharynx prepares to receive bolus
o Pharynx is pulled superiorly, forward by
 Stylopharyngeus (IX)
 Salpingopharyngeus (IX, X)
 Palatopharyngeus (IX, X)
Opening of the auditory tube
o Actions of levator palatini, tensor palatini, and
salpingopharyngeus open auditory tube
 Pressure equalizes between nasopharynx & middle ear
Closure of the oropharynx
o Kept shut by palatoglossus (IX, X)
Laryngeal closure & elevation
o Vocal fold closure, adduction, is essential to avoid aspiration
during swallowing
 Lateral cricoarytenoids (X, recurrent laryngeal)
 Oblique, transverse heads of arytenoids (X, recurrent
laryngeal)
o Creates a swallowing apnea
o Swallowing occurs during expiration usually
o Laryngeal elevation by
 stylopharyngeus
 salpingopharyngeus


 palatopharyngeus
 inferior constrictor
Hyoid elevation
o Digastric and stylohyoid m. (V & VII)
Bolus transits pharynx
o Movement occurs by pharyngeal peristalsis
o Sequential contraction by superior, middle and inferior
constrictor muscles
C. Esophageal Phase (Involuntary)
 Esophageal peristalsis
o Bolus is propelled first by striated muscle (recurrent
laryngeal, X)
o Then by smooth muscle, (X), at a rate of 3-5cm/s
o Relaxation of upper and lower esophageal sphincters
necessary
 Relaxation phase
o The larynx, hyoid, pharynx move inferiorly mostly by elastic
recoil of muscles that constricted earlier
4.) Demonstrate the structures within the tympanic (middle ear)
cavity, including ossicles, musculature and neurovascular
components, including identification of which type of fibers the
nerves carry.
Ossicles
 Malleus (bound to tympanic membrane)
 Incus (connecting arm to stapes)
 Stapes (most likely not seen on dissection)
Muscles
 Stapedius (CN VII)
 Tensor tympani (CN V: medial pterygoid nerve, from V3)
Neurovasculature
 Chorda tympani (GVE, SA)
o Sensory taste fibers from anterior 2/3 of tongue
o Presynaptic parasympathetic fibers to the submandibular
ganglion, providing secretomotor innervation to the
submandibular and sublingual salivary glands
o * Sensation from the middle ear is provided by the
glossopharyngeal nerve
5.) Describe otitis media and why it affects children more often than
adults, specifically in relation to the structures that can be
demonstrated in the cadaver dissections.
Otitis media is an inflammation of the middle ear / Eustachian tube. It
affects children more than adults for two developmental reasons. Initially,
the young skull has a very short external auditory meatus and a
horizontally-oriented Eustachian tube. Therefore, there isn’t an
immunoprotective advantage of hair and cerumen with a lengthened
external auditory meatus and when a pathogen causes AOM (acute otitis
media) in a child, the smaller and horizontal Eustachian tube makes it very
difficult for the middle ear to drain itself of pathogen and associated fluids.
Above, see the difference locations of the external auditoy meatus between
the fetal and adult skull.
6.) Demonstrate the structures of the inner ear and describe the
innervation (specific fibers carried) and vascular supply within the
petrous part of the temporal bone.
Cochlea (basic anatomy)
 Oval window


Round window
Spiraling tubular organ, subdivided into 3 tubes
o Scala tympani
o Scala media
 Organ of Corti, endolymph-filled
o Scala vestibuli

Modiolus is the central axis of the spiral, contains spiral ganglia
from CN VIII (SA)
 Helicotrema, at apex of media and vestibuli
Vestibule
 Saccule
o up and down head movements
 Utricle
o Linear, horizontal head movements
Semicircular canals
 3 loops, oriented in 3D (x,y,z) dimensions
All sensed by vestibular branch of CN VIII
Vascular supply to the inner ear is provided by the labryrinthine artery, a
branch from the basilar artery.
7.) Demonstrate the craniovertebral joints and describe the
attachments of the alar ligament, cruciform ligament and tectorial
membrane / posterior longitudinal ligament within the vertebral
canal.
Alar ligament
 from sides of dens to tubercles of medial occipital condyle
Cruciform ligament
 Vertical portion, from body of axis to basilar occiput
 Transverse portion, posterior to dens, from one side of atlas to the
other
Tectorial membrane / PLL
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

Tectorial membrane is an extension of the PLL superiorly
Fixed at posterior surface of the atlas
Attaches to the basilar groove of occiput, anterior to foramen
magnum, and is continuous with the dura
Week 28
1/29/2013 5:21:00 AM
1. Demonstrate the extraocular muscles of the eye, including
identification of their attachments and innervation.
Notes:



All rectus musculature + the superior oblique originate from the
annulus and insert of different aspects of the eyeball.
The actions of each muscle are not required for this objective (see
#2)
Don’t forget about the superior oblique’s course through the
trochlea
2. Describe the extraocular muscle strength test (H pattern) to
determine isolated function of individual muscles. Put one of your
peers through this test and identify which muscle is tested in each
position.
The below image is for the left eye. Mirror image of this would be the right
eye. Practice with a friend. The oblique muscle actions are isolated when
the eye is adducted, and the inferior superior rectus muscles are isolated
when abducted.
3. Demonstrate the nerves of the orbit, identify the branches and
indicate which specific fibers those branches carry.
CN II: optic nerve (SA)
CN III: oculomotor nerve (BE)
 Superior ramus to levator palpebrae superioris & superior rectus
 Inferior ramus to rest of oculomotor muscles
CN IV: trochlear nerve to superior oblique m (BE)
CN V:
 Ophthalmic (GSA)
o Nasociliary (GSA)
 Anterior & posterior ethmoidal
 Infratrochlear
 Long ciliary nerve
o Lacrimal (GSA)
 Communicates with zygomatic branch from maxillary
nerve (V2) which provides post-synaptic
parasympathetic innervation (pterygopalatine ganglion)
to the lacrimal gland (GVE)
o Frontal (GSA)
 Supratrochlear n.
 Supraorbital n.
CN VI: Abducens nerve to lateral rectus m
4. Demonstrate the arterial supply and venous drainage of the orbit,
including sites of anastomosis.
The first branch of the internal carotid artery (ICA) is the ophthalmic artery.
From the ophthalmic artery, we have an orbital group of branches and an
ocular group of branches.
Orbital
 Lacrimal
 Supraorbital
 Ethmoidal branches
 Internal palpebral
 Frontal
 Nasal
Ocular
 Long & short ciliary branches
 Anterior ciliary
 Central retinal
 Muscular
Anastamoses (with branches of the ECA)
 Note the picture, the anastomoses include the two eyelid arches
and at the infraorbital region with the facial artery
Venous Drainage
 Vortex veins
o They drain the actual eye, superior drains into superior
ophthalmic vein, inferior vortex veins drain into the inferior
ophthalmic vein.
 Superior & inferior ophthalmic veins
o Drain into the cavernous sinus
o
o
5. Demonstrate the lacrimal gland, including discussion of its
innervation in regards to specific branches and fibers. Be able to
detail the drainage of tears from the orbit.
Situated on the superior lateral aspect of the eyeball, the lacrimal gland has
both parasympathetic and sympathetic fibers.
Parasympathetic


Originating from the lacrimal nucleus supplying the facial nerve, the
facial nerve gives off the greater petrosal nerve.
Meets the deep petrosal nerve and travels to the pterygopalatine
ganglion
 Once through the infraorbital fissure, the zygomatic branch carries
these post-synaptic fibers to the lacrimal nerve to the gland
Sympathetic
 Originating from the superior cervical ganglion (stellate) and travels
along middle meningeal artery

Merge with deep petrosal nerve, which joins the greater petrosal
(see above)
 Does not synapse in pterygopalatine ganglion
 Continue with the zygomatic branch to the lacrimal**
Tear Drainage
 Two regions of ductage; orbital and palpebral
 Tears from eye are collected in the lacrimal punta, which are small
holes in the eyelid
 These pass tears to the lacrimal sac, which drains via the
nasolacrimal duct into the inferior nasal meatus
6. Demonstrate the cavernous sinus and the cranial nerves in its
lateral wall. Describe potential routes of infection that can impact
this space.
The lateral wall of the sinus is occupied by cranial nerves III, IV, V1, V2.
Infection is possible by the following routes:
 From the external face (danger area of the face)

o Routed through the superior or inferior ophthalmic veins
o Or deep facial vein, pterygoid plexus of veins @ foramen
ovale
Infection can spread by cavernous sinus thrombosis, which will
originate from:
o Sphenoid sinus
o Ethmoidal air cells
o Nasal furuncle
o Dental infections