Review

2. TERMINOLOGY
 Cranial cavity: This compartment houses the brain, its associated meninges and
blood supply and the twelve pairs of cranial nerves.
 Orbits: Pyramidal-shaped cavities in the facial skeleton, the orbits contain and
protect the eyes and their muscles, nerves and vessels, and most of the lacrimal
apparatus.
 Ear: Each ear is divided into external, middle and inner portions; the middle and
inner ears are located entirely within the “petrous portion” of the temporal bone, the
external ear is located in the temporal bone and in the face.
 Nose: This superior-most portion of the respiratory system is divided into right and
left nasal cavities by the midline nasal septum.
 Oral cavity: This compartment houses the teeth, tongue, two of the three pairs of
major salivary glands and their associated nerves and vessels.

3. WHAT ARE THE COMPARTMENTS OF THE NECK
 Deep muscular compartment: Enclosed within the prevertebral layer of the deep
cervical fascia; this compartment contains the cervical vertebral column and its
associated muscles.
 Visceral compartment: Enclosed by the pretracheal layer of the deep cervical fascia;
this compartment contains the cervical viscera (pharynx/esophagus, larynx/trachea,
thyroid gland) and their associated nerves and vessels.
 Carotid sheath: Enclosed by contributions from all three layers of the deep cervical
fascia; this compartment contains the common carotid and internal carotid arteries,
the internal jugular vein and the vagus nerve (CN X).
 The investing (superficial) layer of the deep cervical fascia encloses all three deep
compartments and surrounds the neck like a cervical collar; on each side it splits to
“invest” two muscles (trapezius and sternocleidomastoid) and two salivary glands
(parotid and submandibular).

4. NAME 3 SYNOVIAL JOINTS IN THE HEAD
 Temporomandibular joint (TMJ): this singular joint occurs between the right and left
condyles of the mandible and the right and left mandibular fossae of the temporal
bones, respectively
 Each articulation is divided in two by an intervening fibrocartilaginous disc
 Movements allowed include protrusion and retrusion, and rotation (elevation and
depression) of the mandible.
 Atlanto-occipital joints: between the lateral masses of the C1 vertebra and the
occipital condyles of the skull
 primary movements permitted at these joints are flexion and extension
 Interossicular joints: between the maleus and incus and between the incus and the
stapes of the middle ear
 the mobile chain of auditory ossicles transmits vibrations from the tympanic
membrane (eardrum) to the sensory organs of the inner ear.

5. INTERNAL CAROTID ARTERY
 From the carotid bifurcation, the internal carotid artery ascends vertically within
the neck without branching and enters the carotid canal of the temporal bone.
Upon exiting the carotid canal the internal carotid artery passes through the
cavernous sinus. Posterior to the optic canal the internal carotid artery pierces
the dural roof of the cavernous sinus and gives off the ophthalmic artery. It then
enters the subarachnoid space at the base of the brain where it terminates as
the middle and anterior cerebral arteries.

6. EXTERNAL CAROTID ARTERY
 From the carotid bifurcation the external carotid artery exits the carotid sheath
and ascends, slightly anterior to the internal carotid artery, to enter the
substance of the parotid gland. Within the gland the external carotid artery
gives rise to its two terminal branches: the superficial temporal artery and the
maxillary artery.
 Within the neck the external carotid artery gives rise to the following clinically
important branches:
 Superior thyroid artery. This artery descends to supply the thyroid gland.
 Lingual artery. This artery supplies structures in the floor of the oral cavity
(i.e., Tongue, mucosa, sublingual gland).
 Facial artery. This artery supplies the muscles of facial expression, the
lacrimal sac and the anterior aspect of the nasal septum.
 Posterior auricular. This artery supplies the scalp posterior to the ear
(auricle).
 Occipital artery. This artery supplies the posterior aspect of the scalp.

7. WHICH ARTERIES SUPPLY THE HEAD AND NECK
AND WHAT ARE THEIR ORIGINS
 Common carotid  Internal carotid
 Subclavian  Vertebral-Basilar
 On the right side from the Brachiocephalic trunk
 On the left side direct from the aortic arch

8. HOW DOES THE VERTEBRAL ARTERY ENTER
THE CRANIAL CAVITY
 The vertebral artery is the FIRST branch of the subclavian
 It branches between the subclavian outlet and the interscalene triangle
 Ascends through the transverse foramina starting at C6
 Passes along superior surface of posterior arch of C1
 Enters through the foramen magnum

9. DESCRIBE THE DRAINAGE OF THE CRANIAL
CAVITY
 The dural venous sinuses empty into the Internal jugular veins
 Dural venous sinuses are the endothelial- lined channels between the layers
of the dura mater
 NO VALVES OR SMOOTH MUSCLE
 Extracranial veins empty into internal jugular vein or subclavian
 The internal jugular and subclavian  brachiocephalic  superior vena cava
 Intra and extra-cranial veins communicate via EMISSARY VEINS
 IMPORTANT ROUTE OF INFECTIONS

10. DESCRIBE THE LOCATION OF THE DEEP
CERVICAL CHAIN
 The deep cervical chain consists of 15-30 nodes that lie along the carotid
sheath, deep to the sternocleidomastoid muscle.
 Deep cervical nodes are subdivided into two groups based upon their location
relative to the superior belly of the omohyoid muscle: Superior and Inferior

12. THE SKULL

13. SUTURES
 Sutures are tension-adapted growth centers of the skull; new bone tissue is
deposited at sutures (along the margins of both bones) in direct response to the
tension generated within them as the brain, eyes, nasal septum, nasal mucosa,
and tongue expand, and as the teeth develop and erupt into occlusion.
 Sutures normally fuse after growth has ceased. Some sutures, especially
those of the calvaria fuse long after the growth has ceased. For example,
fusion of the sagittal and coronal sutures typically begins sometime between
the ages of 30 and 40 years.

14. OSSIFICATION
 The bone of the skull is produced through both endochondral and
intramembranous ossification.
 Most of the bone of the basicranium (ethmoid and portions of frontal, sphenoid,
temporals and occipital) is preformed in cartilage
 Bone of the calvaria (parietal and portions of frontal, sphenoid, temporals and
occipital) and most of the bones of the face are preformed in membrane.

15. DESCRIBE THE FUNCTION OF CRANIAL
FONTANELLES DURING PARTURITION.
 The softness of the cranial bones of the neonate and their loose connections at
sutures enable the skull to change shape (mold) as it passes through the birth
canal.
 Anterior, anterolateral (sphenoid) and posterolateral (mastoid)

16. PALATINE, VOMER, ZYGOMATIC BONES
Mandible

17. IDENTIFY THE CLINICAL SIGNIFICANCE OF THE
ANTERIOR FONTANELLE IN NEONATES.
 Palpation of the fontanelles is a part of the physical examination of an infant
 A bulging or tense fontanelle indicates raised intracranial pressure
 A sunken fontanelle indicates dehydration
 Cerebral arteries cause pulsation and blood samples can be obtained here

18. IDENTIFY THE BONE IN THE SKULL THAT
HOUSES THE CAROTID CANAL
 Petrous Temporal Bone
 Also inner and middle ear and facial canal
 Structures of the inner ear = cochlea, semicircular canals
 Structures of middle ear = Auditory Ossicles = malleus, incus, and stapes
 The internal carotid artery exits the petrous bone, enters the cavernous
sinus, does a big wiggle and then branches into the ACA and MCA

19. LIST THE FOUR BONES INVADED BY
PARANASAL AIR SINUSES DURING BIRTH
 Frontal
 Ethmoid
 Sphenoid
 Maxillary

21. THE SKULL
 The neurocranium is further divided
into the cranial base (basicranium)
and the calvaria. The calvaria
consists of the flat bones that form
the walls and roof of the
neurocranium.
 Viscerocranium: frontal, maxilla,
nasal, zygomatic, palatine,
mandible

22. WHAT IS THE CAUSE OF CRANIOSYNOSTOSIS?
 Premature fusion of sutures

23. WHAT ARE THE COMPONENTS OF THE NASAL
SEPTUM
 Vomer
 Perpendicular plate
of ethmoid
 Nasal septum
cartilage

24. NAME TWO IMPORTANT GROWTH CARTILAGES
OF THE SKULL
 Spheno-occipital synchondrosis
 Nasal septum cartilage
 Can be affected by achondroplasia!

25. Pterion
(“P” is silent)
Mastoid process
Styloid process
Ramus of mandible
Body of mandible Angle of mandible

26. PTERYGOPALATINE FOSSA
Pterygopalatine fossa
(“P” is silent)

27. THE INTERNAL CAROTID ARTERY PASSES OVER
WHICH FORAMEN BEFORING ENTERING
CANAL?
 Foramen lacerum

28. NAME THE SEGMENTS OF THE INTERNAL
CAROTID
 Certical cervical segment in the neck, followed by a sharp horizontal bend as
the internal carotid enters the temporal bone as the petrous segment.
 Cavernous segment as the internal carotid begins an S-shaped turn, also
known as the carotid siphon, within the cavernous sinus.
 Passes the anterior clinoid process to pierce the dura and bends posteriorly to
enter the subarachnoid space as the supraclinoid, or intracranial segment.
 Main branches of the supraclinoid internal carotid artery can be remembered by
the mnemonic OPAAM: Ophthalmic, Posterior communicating, Anterior
choroidal, Anterior cerebral, and Middle cerebral arteries.
 The ophthalmic artery usually arises from the bend in the internal carotid just
after it enters the dura. The ophthalmic artery enters the optic foramen with the
optic nerve and provides the main blood supply to the retina.

31. MIDDLE EAR IS LOCATED LATERAL OR MEDIAL
TO THE SEMICIRCULAR CANALS?
 Lateral

36. IN WHAT LOBE DOES THE LATERAL (SYLVIAN)
FISSURE TERMINATE?
 The Parietal Lobe

37. NAME FOUR FUNCTIONS OF THE TEMPORAL LOBE
 Speech
 Memory
 Olfaction
 Audition

38. NAME THE TWO BLOOD SUPPLIES OF THE BRAIN
 Vertebral-Basilar
 Temporal
 Occipital
 Brain stem
 Cerebellum
 Internal Carotid
 Diencephalon
 Frontal
 Parietal
 Basal Ganglia
 Internal Capsule
 VERY LITTLE MIXING

41. NAME TWO KEY SYMPTOMS OF A BLOCKAGE OF THE
VERTEBRAL-BASILAR CIRCULATION
 Vision problems (occipital)
 Dizziness (cerebellum)

42. NAME THE BRANCHES OF THE VERTEBRAL
ARTERIES
 PICA
 Anterior Spinal
 Posterior Spinal
 Basilar

43. PICA
 PICA runs circumferentially around the medulla
 Gives off penetrating branches that supply the dorsolateral medulla and the
choroid plexus of the fourth ventricle.
 PICA then continues superiorly to supply posterior and inferior parts of the
cerebellum and cerebellar peduncles.

44. ANTERIOR SPINAL
 Supplies median and paramedian aspects of the medulla oblongata and
anterior 2/3 of spinal cord

45. NAME THE BRANCHES OF THE BASILAR ARTERY
 AICA
 Pontine
 Superior Cerebellar
 Posterior Cerebral Artery

46. AICA
 Travels along the caudal end of the middle cerebellar peduncle
 Supplies the upper medulla and lower pons, and the anterior inferior surface of
the cerebellum.

47. SUPERIOR CEREBELLAR
 Travels along the pons and middle cerebellar peduncle
 Supplies the superior cerebellum

48. POSTERIOR CEREBRAL ARTERIES
 The basilar artery branches at the level of the midbrain and each posterior
cerebral artery supplies:
• MEDIAL and INFERIOR surface of the temporal and occipital lobes,
 Thalamus
 Internal structures
 Hippocampus*
 Occlusion of PCA may lead to visual field deficits. Patients may be unable to
drive or read, resulting in major limitations in their quality of life, despite normal
motor function.
 Thalamic involvement can produce sensory loss or thalamic pain syndrome, a
hypersensitivity to pain.

49. NAME THE BRANCHES OF THE INTERNAL
CAROTID SYSTEM
 Opthalmic artery
 Middle cerebral artery
 Anterior cerebral artery
 Anterior choroidal artery
 Lenticulostriate arteries

50. OPTHALMIC
 Supplies orbit, eye and scalp
 Shade going down over one eye
 RISK OF FUTURE STROKE

51. MIDDLE CEREBRAL ARTERIES
 Runs laterally between the temporal lobe and the frontal lobe to emerge from
the LATERAL sulcus (sylvian fissure).
 Each MCA divides into several branches to supply the LATERAL surface of the
hemisphere, including the primary motor and primary sensory areas of cortex,
located in the pre-central and post-central gyri.

52. ANTERIOR CEREBRAL ARTERIES
 Runs along the medial surface of each cerebral hemisphere and curves
dorsally and caudally to lie superior to the corpus callosum – wraps around
corpus callosum
 The ACAs supply the MEDIAL portions of the frontal and parietal lobes as well
as the corpus callosum.
 Distal branches of the ACAs supply the MEDIAL surface of the parietal lobe,
including the paracentral lobule.

53. LENTICULOSTRIATE ARTERIES
 Small arteries arising from the middle and anterior cerebral arteries that
penetrate the brain in the anterior perforated substance
 Supply deep structures: basal ganglia and internal capsule
 These small vessels arise from the initial portions of the middle cerebral artery
before it enters the Sylvian fissure and they penetrate the anterior perforated
substance to supply large regions of the basal ganglia and internal capsule.
 Lacunar infarct

54. ANTERIOR CHOROIDAL ARTERIES
 Branch off INTERNAL CAROTID
 Supplies the optic tracts and the posterior limb of the internal capsule.
 Its territory includes portions of the globus pallidus, putamen, thalamus
(sometimes involving part of the lateral geniculate nucleus), and the posterior
limb of the internal capsule extending up to the lateral ventricle
 Recall that the posterior limb of the internal capsule contains important motor
pathways through the corticobulbar and corticospinal tracts. Thus, lacunar
infarction in either the lenticulostriate or anterior choroidal territories often
causes contralateral hemiparesis

55. OPTIC CHIASM
 The point of intersection between the optic nerve CN II and the optic tracts

56. DAMAGE TO THE FRONTAL LOBE IMPAIRS…
 the ability to make decisions, including anticipating the future consequences of
an action and responding appropriately in social situations.

57. THE CINGULATE GYRUS IS INVOLVED IN…
 The cingulate gyrus is a prominent part of the limbic system, which plays a role
in emotion, behavior, long-term memory and olfaction.

58. A PATIENT WHO HAS DIFFICULTY RECOGNIZING
ONE SIDE OF THEIR BODY MAY HAVE DAMAGE
TO THIS REGION
 Inferior parietal lobule

59. THE INSULAR CORTEX IS INVOLVED IN…
 Taste
 Visceral physiological function
 Nicotine addiction

60. Blood vessel Deficit
Left MCA Right hemiplegia,
hemianesthesia, homonymous
hemianopia and global aphasia.
Left gaze preference.
Right MCA Left hemiplegia,
hemianesthesia, homonymous
hemianopia and profound left
hemineglect. Right gaze
preference.
ACA Contralateral leg weakness and
sensory loss, grasp reflex,
frontal lobe behavioral
abnormalities
PCA Right homonymous
hemianopia. Infarcts extending
to thalamus and internal
capsule may cause
hemiparesis or hemianesthesia

61. LACUNAR SYNDROMES

63. GIVEN HORIZONTAL, CORONAL OR
MIDSAGITTAL SECTIONS OF THE BRAIN,
IDENTIFY THE VASCULAR TERRITORIES OF MCA,
ACA, PCA, PICA, SCA, AICA, AND THE ANTERIOR
CHOROIDAL AND LENTICULOSTRIATE ARTERIES.

67. NAME THE ARTERIES THAT SUPPLY MEDIAL
BRAINSTEM STRUCTURES. NAME THE ARTERIES
THAT SUPPLY DORSOLATERAL BRAINSTEM
STRUCTURES.
 Medial: Basilar, Anterior Spinal Artery
 Dorsolateral: PICA, SCA, PCA

69. NAME THE BLOOD VESSELS THAT SUPPLY THE
SPINAL CORD.
 The Spinal Cord is supplied by the vertebral
arteries and the anterior and posterior spinal
arteries.
 Paramedian branches penetrate along the
ventro-medial fissure.
 Circumferential branches penetrate white
matter on the lateral aspect of the cord to
supply ventral and lateral portions of the cord”

70. DEFINE A BERRY ANEURYSM. DISCUSS THE
SIGNIFICANCE OF BERRY ANEURYSMS IN
SUBARACHNOID HEMORRHAGE.
 A berry or saccular aneurysm is an
aneurism that arises in the small branching
points of arteries near the circle of Willis
 Abnormal widening due to weakness of
vessel
 Although a cerebral aneurysm may be
present without symptoms, the most
common initial symptom of a cerebral
saccular aneurysm is a sudden headache
from a subarachnoid hemorrhage (SAH).
 85% in anterior circulation
 Subhyaloid hemorrhages are
pathognomonic for subarachnoid
hemorrhage

72. LIST THE THREE DIVISIONS OF CN V
(TRIGEMINAL) AND IDENTIFY THE NERVE
COMPONENTS CARRIED BY EACH.
 V1 - Opthalmic
 sensory only
 V2 - Maxillary
 sensory only
 V3 - Mandibular
 sensory + motor root
innervations muscles of
mastication (masseter,
temporalis, medial and
lateral pterygoids and
some other smaller ones

73. THE FACIAL NERVE EXITS THE SKULL THROUGH
THE ________?
 Stylomastoid foramen

74. LIST THE THREE PRIMARY BRANCHES OF CN VII
(FACIAL) AND DESCRIBE THEIR FUNCTIONS.
 “Motor”
 Motor to muscles of facial expression; motor to stapedius muscle of middle
ear
 Greater petrosal
 Delivers preganglionic parasympathetic fibers to pterygopalatine ganglion
 Chorda tympani
 Delivers preganglionic parasympathetic fibers to submandibular ganglion;
taste sensation from anterior 2/3 of tongue

75. IDENTIFY THE SENSORY AND AUTONOMIC
FUNCTIONS OF CN IX (GLOSSOPHARYNGEAL).
 Somatic Sensory from posterior 1/3 of tongue, nasopharynx, oropharynx,
tympanic cavity & internal surface of tympanic membrane, posterior soft palate
 Taste sensation from posterior 1/3 of tongue
 Visceral sensation from carotid body and carotid sinus
 Autonomic preganglionic parasympathetic innervation to otic ganglion (parotid
gland)

76. IDENTIFY THE SENSORY, MOTOR AND
AUTONOMIC FUNCTIONS OF CN X (VAGUS).
 Superior laryngeal nerve
 Sensory from larynx superior to the vocal folds (internal branch); motor to
cricothyroid and cricopharyngeus muscles (external branch)
 Inferior (recurrent) laryngeal nerve
 Sensory from vocal folds and inferior larynx
 Motor to all intrinsic laryngeal muscles except cricothyroid
 Additional branches
 Sensory from dura, auricle, external auditory meatus, laryngopharynx
 Visceral sensory from carotid body and carotid sinus, thoracic and abdominal
viscera
 Motor to pharynx, uvula and elevator of soft palate
 Autonomic preganglionic parasympathetic innervation to terminal ganglia in walls
of thoracic and abdominal viscera

77. LIST THE THREE CRANIAL NERVES THAT CARRY
SPECIAL SENSORY FIBERS AND IDENTIFY THE
MODALITY TO WHICH EACH IS DEDICATED.
 CN I - Olfactory - Smell
 CN II - Optic - Vision
 CN VIII - Vestibulocochlear – Hearing and balance

78. LIST THE TWELVE CRANIAL NERVES AND
IDENTIFY THE FORAMINA OF THE CRANIAL
BASE THAT TRANSMIT THEM FROM THE
CRANIAL CAVITY.
 CN I – Olfactory - Cribriform plate of ethmoid bone to nasal cavity
 CN II – Optic - Optic canal of sphenoid bone to orbit
 CN III – Oculomotor - Superior orbital fissure to orbit
 CN IV – Trochlear - Superior orbital fissure to orbit
 CN V – Trigeminal
 Opthalmic – Superior orbital fissure
 Maxillary – Foramen rotundum
 Mandibular – foramen ovale
 CN VI – Abducens - Superior orbital fissure to orbit
 CN VII – Facial – Internal acoustic meatus and out stylomastoid foramen
 CN VIII – Vestibulocochlear – Internal acoustic meatus
 CN IX – Glossopharyngeal – Jugular foramen
 CN X – Vagus – Jugular foramen
 CN XI – Spinal Accessory – Enters foramen magnum, exits jugular foramen
 CN XII – Hypoglossal – Hypoglossal canal

80. LIST THE NERVES THAT PROVIDE SENSORY
INNERVATION TO THE DURA AND DESCRIBE
THEIR GENERAL DISTRIBUTION.
 Anterior fossa: trigeminal nerve – V1. V2. V3
 Posterior fossa: C1-3 and, Vagus nerves

81. WHICH THREE CRANIAL NERVES ARE MIXED
NERVES?
 Facial
 Glossopharyngeal
 Vagus
 Also Trigeminal…

84. LAYERS OF HEAD/NECK
 Skin
 Connective tissue (Dense) – External blood vessels are here
 Aponeurosis of the epicranium
 Loose connective tissue
 Pericranium – Diploe
 Emissary veins
 Periosteal Dura mater
 Meningeal Dura mater – meningeal arteries, dural venous sinuses
 Bridging veins, Arachnoid granulations
 Arachnoid mater
 Subarachnoid Space – Cerebral/cerebellar arteries/veins
 Pia Mater
 Brain

86. THE CAUDAL BORDER OF THE PARIETAL LOBE IS
BEST SEEN IN WHAT VIEW
 Medial : the parieto-occipital sulcus is apparent in this view.

87. WHAT LIES BETWEEN THE TWO CEREBRAL
PEDUNCLES?
 Interpeduncular fossa: exit of oculomotor nerve
 Mamillary bodies

88. THE PRECENTRAL AND POSTCENTRAL GYRI
COME TOGETHER TO FORM THE…
 Paracentral lobule

89. THE INTRAPARIETAL SULCUS DIVIDES THESE
TWO STRUCTURES
 Superior and Inferior Parietal Lobules

90. IN THE OCCIPATAL LOBE, THE _____ FISSURE
DIVIDES THE ______ AND _______
 Calcarine
 Cuneus : upper retina – lower visual field
 Lingual gyrus: lower retina – upper visual field

91. THE CAUDAL PORTION OF THE SUPERIOR
TEMPORAL GYRUS HAS SMALL OBLIQUE GYRI
 Transverse temporal gyri (of Heschl)
 Primary auditory cortex

92. THESE GYRI CAN BE VIEWED ON THE INFERIOR
SURFACE OF THE BRAIN
 Parahippocampal gyrus (medial)
 Uncus
 Occipito-temporal

93. NAME THE FOUR PARTS OF THE CORPUS
CALLOSUM FROM ROSTRAL TO CAUDAL
 Rostrum
 Genu
 Body
 Splenium

94. NAME THE 5 COMMISSURES
 Corpus callosum
 Anterior commissure
 Posterior commissure
 Fornix
 Optic chiasm

95. WHAT IS THE RELATION OF THE
HYPOTHALAMUS TO THE THALAMUS
 The hypothalamus is the rostral and inferior border of the thalami.
 The hypothalamus is a smaller brain structure that comprises the inferolateral
borders of the third ventricle.
 The third ventricle forms the medial border of the hypothalamus.
 The anterior border of the hypothalamus is the lamina terminalis, a thin sheet
of neural tissue that marks the rostral boundary of the original neural tube
from which the brain and spinal cord developed.
 The optic chiasm (mentioned above) is the rostral border of the
hypothalamus.
 The mammillary bodies form the caudal border of the hypothalamus
 The hypothalamus also includes the infundibulum, which is the pituitary stalk
connecting the pituitary to the hypothalamus. The hypothalamus has
homeostatic and reproductive functions.

96. NAME THE IMPORTANT CISTERNS IN THE
CRANIAL CAVITY
 Cerebellomedullary cistern
 Superior cistern
 Interpeduncular cistern
 Pontine cistern
 Chiasmatic cistern
 Cistern of lateral fossa
 Lumbar cistern

97. THE CSF ESCAPES TO THE SUBARACHNOID
SPACE THROUGH…
 Lateral foramina of Luschka
 Midline median aperture of Magendie

99. CHOROID PLEXUS
 Choroid Plexus = highly specialized tissue with elaborate folds and many villi
projecting into the four large ventricles of the brain
 Found on the roofs of the third/fourth ventricles and in parts of the two lateral
ventricular walls = regions where the ependymal lining directly contacts pia
mater
 FUNCTION = remove water from blood and release it as CSF
 CSF = clear, containing Na, K, and Cl ions but little protein
 Produced continuously and provides the ions required for CNS neuronal activity
and also serves as a shock absorber

100. NAME THE THIN MEMBRANE THAT SEPARATES
THE LATERAL VENTRICLES
 Septum Pallucidum

101. WHAT IS THE RESULT OF A BUILDUP OF CSF
 Hydrocephalus

102. EACH VENTRICLE IS ASSOCIATED WITH A
PRINCIPLE BRAIN REGION..
 Lateral ventricle – telencephalon
 Third Ventricle – diencephalon
 Cerebral aqueduct – midbrain - MESENCEPHALON
 Fourth ventricle – medulla and pons –
METENCEPHALON/MYELENCEPHALON

103. WHAT NERVE EXITS THE BRAIN AT THE SULCUS
THAT DIVIDES THE OLIVES FROM THE
MEDULLARY PYRAMIDS
 Hypoglossal nerve

104. THE SUPERIOR COLLICULI ARE INVOLVED IN…
 Coordinating eye movements – SEEING
 Inferior - auditory

105. A THIN SHEET OF NEURAL TISSUE THAT MARKS
THE ROSTRAL BOUNDARY OF THE ORIGINAL
NEURAL TUBE FROM WHICH THE BRAIN AND
SPINAL CORD DEVELOPED
 Lamina Terminalis – anterior border of hypothalamus

107. IDENTIFY THE ARTERY OF ORIGIN OF THE
MIDDLE MENINGEAL ARTERY
 External carotid artery → Maxillary artery → Middle meningeal artery
 Middle meningeal through foramen spinosum

108. DISCUSS THE SIGNIFICANCE OF THE MIDDLE
MENINGEAL ARTERY WITH RESPECT TO
CALVARIAL FRACTURES AND EPIDURAL
(EXTRADURAL) HEMORRHAGE.
 The middle meningeal artery lies under the thin pterion bone. A strong blow to
the side of the head can cause this bone to fracture. A fracture in the pterion is
called a calvarial fracture and commonly causes tears in the middle meningeal
arteries below. These tears lead to bleeding into the epidural space called
epidural (extradural) hemorrhage.

109. DISTINGUISH A DURAL VENOUS SINUS FROM A
PARANASAL SINUS.
 Dural Venous Sinus
 Between dural layers
 Contains blood and CSF
 Paranasal sinus
 Between cranial bones around nose
 Contains air

110. VENOUS DRAINAGE OF THE BRAIN…
 Cerebral veins→ Superior sagittal sinus→ confluence of sinuses→ transverse sinus (usually
right)→ becomes sigmoid sinuses → Internal jugular vein
 Inferior sagittal sinus→ straight sinus→ confluence of sinuses→ transverse sinus (usually left)
→ becomes sigmoid sinuses→ Internal jugular vein
 Drainage is asymmetric in that the superior sagittal sinus drains into right transverse
 Ophthalmic veins, middle cerebral veins, sphenoparietal sinus → cavernous sinus  Superior
petrosal sinus→ transverse sinuses→ becomes sigmoid sinuses→ Internal jugular vein
 Inferior petrosal sinus→ Internal jugular vein
 Carvernous sinus drains into both the superior and inferior petrosal sinuses

111. DOES THE SUPERIOR SAGITTAL SINUS USUALLY
DRAIN INTO THE RIGHT OR LEFT TRANSVERSE?
 Right
 Straight Sinus goes to left

113. DISCUSS THE SIGNIFICANCE OF THE BASILAR
PLEXUS AND OCCIPITAL SINUSES IN THE
METASTASIS OF CANCER TO THE VERTEBRAE
AND BRAIN.
 The occipital sinus, along with the basilar plexus (a.k.a transverse sinuses) of
veins located on the basioccipital clivus communicate with the internal vertebral
venous plexus through the foramen magnum.
 Because these venous channels are valveless, compression of the thorax,
abdomen and pelvis (during coughing or heavy straining) may force venous
blood from these regions into the internal vertebral venous system and
subsequently into the dural venous sinuses.
 As a result, pus in abscesses and tumor cells in these regions may spread to
the vertebrae and brain.

114. DEFINE “BRIDGING” VEINS. DISCUSS THE
SIGNIFICANCE OF BRIDGING VEINS TO DURAL
BORDER (SUBDURAL) HEMATOMAS.
 “Cerebral and cerebellar veins - veins which drain brain tissue – drain to the
dural venous sinuses. These veins are often referred to as “bridging veins”
because they must “bridge” the subarachnoid space in order to gain access to
and open into the dural venous sinuses.
 In light of this, extravasated blood from a torn bridging vein collects between
the dura and the arachnoid and results in a subdural (dural border) hemorrhage

118. LIST THE SEVEN (7) STRUCTURES CONTAINED
WITHIN THE CAVERNOUS SINUS OR ITS WALL.
 Embedded
 Oculomotor
 Trochlear
 Opthalmic CN V1
 Maxillary CN V2
 Pass through
 Abducens
 Internal Carotid

121. CSF IS RECYCLED INTO THE VENOUS SYSTEM
THROUGH THESE STRUCTURES
 Arachnoid granulations  superior sagittal sinus

122. DURAL VENOUS SINUSES LIE AT THE
SEPARATION OF THESE TWO STRUCTURES
 The periosteal and meningeal dural layers

123. THE STRAIGHT SINUS IS FORMED BY THE …
 Inferior sagittal sinus and the great cerebral vein (of Galen)

124. THE SICKLE-SHAPED FOLD OF DURA THAT
EXTENDS INTO THE LONGITUDINAL CEREBRAL
FISSURE OF THE BRAIN,
 Cerebral Falx
 Attachment: Crista Galli

125. TRANSVERSELY-ORIENTED FOLD OF DURA
WITHIN THE TRANSVERSE CEREBRAL FISSURE.
 Cerebellar Tentorium
 Attachment: Petrosal arch

126. LATERAL TO THE CEREBRAL FALX WHICH
ARTERY CAN BE IDENTIFIED WITHIN THE DURA?
 Middle meningeal artery

127. THE SIGMOID SINUS BEGINS WHERE…
 By definition the sigmoid sinus begins where the superior petrosal sinus joins
the transverse sinus
 internal jugular vein begins where the inferior petrosal sinus joins the sigmoid
sinus

129. WHAT THREE STRUCTURES COMPOSE THE
SELLA TURCICA
 Hypophyseal fossa
 Anterior clinoid process
 Dorsum sellae
 HOUSES PITUITARY GLAND

130. THE OLFACTORY BULB SITS WITHIN THIS
STRUCTURE
 Cribiform plate

131. AT WHAT LEVEL DOES THE CAROTID
BIFURCATIONS OCCUR?
 C5

132. THE OPTHALMIC ARTERY TRAVELS WITH THE
________ AND IS A BRANCH OF THE _________
 Optic nerve
 Internal carotid artery

134. DESCRIBE THE FUNCTIONS OF THE FOLLOWING
MUSCLES OF FACIAL EXPRESSION:
ORBICULARIS OCULI (ORBITAL AND PALPEBRAL
PARTS), ORBICULARIS ORIS, BUCCINATOR.
 Orbicularis oculi - Blinking. Keeps your cornea and sclera wet by spreading
“lacrimal fluid” over it.
 Palpebral part - involuntary, closes eye gently (blinking)
 Orbital part - voluntary, more forceful as in photophobia
 Orbicularis oris - seals lips and prevents drooling
 Buccinator - keeps food out of the oral vestibule

135. IDENTIFY WHERE THE MOTOR PORTION OF CN
VII IS VULNERABLE TO INJURY.
 The motor portion of CN VII is vulnerable to injury in neonatal skulls during
forceps delivery due to the absence of the mastoid and styloid processes.
 Otherwise, they can be damaged from any superficial lacerations due to their
superficial location on the face. The facial nerve (motor portion) emerges from
the stylomastoid foramen and enters the parotid gland then branches.
 Also, these facial nerves can be affected in cold weather.

137. DEFINE BELL (BELL’S) PALSY AND LIST ITS
COMMON SYMPTOMS.
 Bell Palsy is an idiopathic injury of the facial nerve resulting in facial paralysis.
 It is thought that inflammation of the facial nerve where it exits the facial canal
causes pressure that impinges on that nerve, damaging the nerve and blocking
conduction.
 Herpes simplex-mediated inflammation is the most common cause of Bell’s
Palsy
 Symptoms include:
 Sudden onset of unilateral facial paralysis
 Sagging Eyebrows
 Inability to close eyes
 Disappearance of nasolabial fold
 Mouth drawn on non-affected side

138. DESCRIBE HOW THE MOTOR PORTION OF CN VII
IS ASSESSED IN A NEUROLOGICAL EXAM.
 Neurological Exam of Motor portion CN VII include:
 Testing Corneal Reflex (involuntary blinking in response of a foreign body
touching the eye)
 Ability to smile, squint and raise eyebrow
 Sound Sensitivity
 From handout: functional testing of the occipitofrontalis muscle (frontal belly) is
used to assess deficits in the facial nerve.

139. DISCUSS TRIGEMINAL NEURALGIA AND
IDENTIFY THE DIVISION OF CN V MOST OFTEN
AFFECTED.
 Trigeminal neuralgia - intense nerve pain (“lightning-like”) that lasts for 15
minutes or more
 There’s often a patch of skin called the “trigger zone” that is hypersensitive to
touch and precipitates the neuralgia
 Maxillary nerve most often affected.

140. LIST THE FIVE LAYERS OF THE SCALP. IDENTIFY
THE LAYER IN WHICH THE ARTERIES AND VEINS
OF THE SCALP ARE LOCATED.
 Skin
 Connective tissue (Dense) - Blood vessels are here.
 Aponeurosis of the epicranium
 Loose connective tissue
 Pericranium

141. DESCRIBE THE FUNCTION OF THE FRONTALIS
PORTION OF THE EPICRANIUS MUSCLE.
 Also known as the epicranius muscle, the two bellies of the occipitofrontalis
muscle are joined by the epicranial aponeurosis.
 Raises the eyebrows and wrinkles the forehead.
 Test for facial nerve function.

142. LIST THE ARTERIES THAT SUPPLY THE SCALP.
IDENTIFY WHICH OF THESE ARTERIES ARE
BRANCHES OF THE EXTERNAL CAROTID
ARTERY AND WHICH ARE BRANCHES OF THE
INTERNAL CAROTID ARTERY.
 Internal carotid artery:
 ophthalmic artery → supratrochlear and supraorbital arteries
 External carotid artery:
 superficial temporal artery
 posterior auricular artery
 occipital artery

144. THE SCALP CONTAINS NUMEROUS VESSELS
AND NERVES.
Branches of ophthalmic
artery (a direct branch of
internal carotid artery)
Direct branches of
external carotid artery

145. IDENTIFY THE DANGER SPACE OF THE SCALP
AND DISCUSS ITS SIGNIFICANCE WITH
RESPECT TO THE SPREAD OF SCALP
INFECTIONS.
 Danger space of the scalp: Loose Connective tissue layer
 Infections in the loose connective tissue layer can also spread to the cranial
cavity via emissary veins. Because the occipital belly of the occipitofrontalis
muscle attaches firmly to the occipital bone, and the epicranial aponeurosis
attaches firmly to the zygomatic arches, infections or blood in the “danger
space” cannot spread into the neck.
 However, because the frontal belly of the occipitofrontalis muscle inserts into
skin, infections and blood in the “danger space” can and do spread to the
eyelids and bridge of the nose

146. DESCRIBE EMISSARY VEINS. DISCUSS THE
SIGNIFICANCE OF EMISSARY VEINS TO THE
SPREAD OF FACE & SCALP INFECTIONS TO THE
CRANIAL CAVITY.
 Emissary veins are a connection between the dural venous sinuses and the
veins of the scalp. Emissary veins travel through small foramina in the calvaria.
Infections in the loose connective tissue layer of the scalp can spread through
these valveless veins and reach the cranial cavity.

147. IDENTIFY THE TWO PRINCIPAL ROUTES
THROUGH WHICH VENOUS BLOOD FROM THE
FACE AND SCALP CAN FLOW TO THE
CAVERNOUS SINUS.
 The pterygoid plexus is located on the surfaces of the pterygoid muscles.
These structures are located in the infratemporal fossa. The pterygoid plexus
connects to the cavernous sinus.
 Venous blood from the face drains via the facial vein. The pterygoid plexus
communicates with the facial vein via the deep facial vein and ophthalmic vein.
 Venous blood from the anterior scalp reaches the cavernous sinus via branches
of the ophthalmic vein on the scalp. These are presumably named the
supratrochlear and supraorbital veins.

149. LIST THE STRUCTURES POTENTIALLY AFFECTED
IN CAVERNOUS SINUS THROMBOPHLEBITIS
 Abducens nerve (CN VI)—most commonly affected
 Internal carotid artery
 Oculomotor nerve (CN III)
 Trochlear nerve (CN IV)
 Opthalmic branch of the trigeminal nerve (CN V1)
 Maxillary branch of the trigeminal nerve (CN V2)
 (Pituitary gland)

150. CAVERNOUS SINUS

151. IDENTIFY THE BONY ARTICULATIONS OF THE
TEMPOROMANDIBULAR JOINT. LIST THE
MOVEMENTS ALLOWED AT THIS JOINT.
 The temporomandibular joint (TMJ) occurs between the mandibular fossa of the
temporal bone and the condyle of the mandible.
 Four movements are allowed at this joint:
 Protrusion
 Retraction
 Elevation
 Depression

152. RELATE THE MOVEMENTS AT THE TMJ TO THE
ARTICULAR DISC INCLUDED WITHIN
 The articular disk within the TMJ divides it into two separate synovial capsules
 Superior capsule—allows for gliding movements within the mandibular fossa
(protrusion/retraction)
 Inferior capsule—allows for rotation of the mandibular condyle against the
articular disk (elevation/depression)
 The coordination of these two “joints” allow the mouth to open widely.

154. LIST THE FOUR MUSCLES OF MASTICATION AND
IDENTIFY THEIR ACTION(S) AT THE
TEMPOROMANDIBULAR JOINT
 Masseter: elevation, retraction (deep fibers)
 Temporalis: elevation, retraction (posterior fibers)
 Lateral pterygoid: protrusion
 Medial pterygoid: protrusion, elevation
 Innervated by V3

155. IDENTIFY THE SENSORY DOMAINS OF THE
FOLLOWING SENSORY BRANCHES OF V3:
AURICULOTEMPORAL, BUCCAL, LINGUAL,
INFERIOR ALVEOLAR, MENTAL
 Buccal: skin and mucosa of cheek (Maxillary)
 Inferior alveolar: gingivae and teeth of lower jaw (Maxillary)
 Auriculotemporal: outer surface of tympanic membrane (Mandibular)
 Lingual: tongue (Mandibular)
 Mental: anterior aspects of the chin and lower lip as well as the buccal gingivae
of the mandibular anterior teeth and the premolars
 Inferior auricular  mandibular

158. IDENTIFY THE FASCIAL LAYER OF ORIGIN OF
THE PAROTID SHEATH. DISCUSS THE
SIGNIFICANCE OF THE PAROTID SHEATH WITH
RESPECT TO THE PAIN ASSOCIATED WITH
PAROTID INFECTIONS.
 Origin of parotid sheath: the investing (superficial) layer of the deep cervical
fascia (head and neck handout)
 Role of sheath in pain associated with parotid infections: Infection causes
inflammation and swelling of the parotid gland. Severe pain occurs because the
parotid sheath limits swelling.

159. IDENTIFY THE STRUCTURES AT RISK OF INJURY
IN A PAROTIDECTOMY AND IN FACIAL
LACERATIONS.
 Branches of facial nerve along with the parotid duct
 External carotid artery
 Surgery on the parotid gland may damage the auriculotemporal nerve of CN V
and cause loss of sensation in the auriculotemporal area. The nerve also
carries postganglionic sympathetic nerve fibers to the sweat glands of the head
and postganglionic parasympathetic nerve fibers to the parotid gland for
salivation. If this nerve is severed, aberrant regeneration may cause sweating
whenever the person eats (Frey syndrome) –

160. LIST THE FOUR CLINICALLY IMPORTANT
GROUPS OF LYMPH NODES OF THE
PERICERVICAL COLLAR AND DESCRIBE, IN
GENERAL TERMS, THE ANATOMICAL LOCATIONS
OF EACH.
 Parotid nodes - attached to the superficial surface of the parotid gland and
embedded within it (lowest members are sometimes referred to as “superficial
cervical nodes”)
 Submandibular nodes - attached to superficial surface of submandibular gland
and embedded within it
 Submental nodes - located inferior to the chin in anterior neck
 Mastoid nodes – superior to sternocleidomastoid muscle

163. IDENTIFY THE STRUCTURES OF THE HEAD AND
NECK INNERVATED BY THE SYMPATHETIC
NERVOUS SYSTEM.
 Body wall viscera
 Sweat glands
 Arrector pili muscles
 Smooth muscle in the walls of blood vessels
 Dilator pupillae – “muscle” of the iris formed by myoepithelium
 Superior tarsal muscle – muscle of the upper eyelid
 Salivary glands

164. IDENTIFY THE PARAVERTEBRAL (CHAIN)
GANGLIA THAT CONTAIN THE POSTGANGLIONIC
SYMPATHETIC NEURONS THAT INNERVATE
THESE STRUCTURES.
 The paravertebral (chain) ganglia involved are located in the cervical region
and have fused into three cervical ganglia: superior, middle, and inferior:
 Superior cervical ganglion – C1-C4
 Middle cervical ganglion – C5-C6
 Inferior cervical ganglion – C7-C8 & usually one or more thoracic ganglia
creating the cervicothoracic or “stellate” ganglia

165. IDENTIFY THE SPINAL CORD SEGMENTS THAT
CONTAIN THE PREGANGLIONIC SYMPATHETIC
NEURONS INVOLVED IN THE INNERVATION OF
HEAD & NECK STRUCTURES.
 T1-T4

166. LIST THE SYMPTOMS OF HORNER’S SYNDROME
AND IDENTIFY ITS ETIOLOGY.
 Horner’s syndrome results from the interruption of a cervical sympathetic trunk
and is manifested by the absence of sympathetically stimulated functions on
the ipsilateral side of the head. This disruption of the sympathetic supply to the
head and neck can be a consequence of many pathological conditions and is
often a product of compression of the sympathetic chain, especially seen in
lung tumors.
 Symptoms:
 Ptosis – drooping of superior eyelid – due to loss of function of superior
tarsal muscle
 Miosis – constriction of the pupil – due to unopposed action of constrictor
pupillae muscle
 Anhidrosis – absence of sweating – due to loss of sympathetic innervation to
sweat glands
 Vasodilation – redness and increased temperature of the skin

167. IDENTIFY THE CRANIAL NERVE ASSOCIATED
WITH EACH PHARYNGEAL ARCH. IDENTIFY THE
SKELETAL ELEMENTS DERIVED FROM ARCHES
Arch Nerve Cartilage
1 V2 Maxillary
V3 Mandibular
Malleus, incus, sphenomandibular
ligament
2 Facial CNVII Stapes, styloid process, stylohyoid
ligament and lesser horns of hyoid bone
3 Glossopharyngeal CNIX Greater horns of hyoid bone
4 Superior laryngeal CNX Thyroid cartilage
6 Recurrent laryngeal CNX Cricoid cartilage

168. IDENTIFY THE STRUCTURES DERIVED FROM
PHARYNGEAL POUCHES 2-4.
Pharyngeal
pouch
Structure Derived
1 Tympanic cavity, auditory tube, tympanic membrane
2 Primordium of palatine tonsil
3 Inferior parathyroid gland, thymus
4 Superior parathyroid gland, ultimobranchial body 
parafollicular C cells

169. DESCRIBE THE DEVELOPMENTAL BASIS OF A
PYRAMIDAL LOBE OF THE THYROID GLAND AND
ACCESSORY GLANDULAR TISSUE.
 Thyroid gland initially appears as a median epithelial thickening in the floor of
the primitive pharynx
 It then descends in the neck anterior to the developing hyoid bone and
laryngeal cartilages to its final position anterior to the trachea
 During the descent, it receives follicular cells derived from the ultimobranchial
body as well as the superior and inferior parathyroid glands
 It also remains connected to the tongue during the descent by a narrow
thyroglossal duct; however, once it gets into its final position the thyroglossal
duct should degenerate
 The pyramidal lobe of the thyroid occurs in individuals when the distal portion of
the thyroglossal duct persists instead of degenerating.

170. DISTINGUISH A THYROGLOSSAL DUCT CYST FROM A
LATERAL CERVICAL CYST.
Thyroglossal duct cyst Lateral cervical cyst
Cause Remnants of thyroglossal
duct persis and give rise to
cyst.
Failed degeneration of cervical sinus.
Location Tongue or midline neck, just
inferior to hyoid bone.
Anterior to anterior border of
sternocleidomastoid muscle.
Presentation Duct moves superiorly with
protrusion of tongue.
Presents in late childhood,
accumulation of fluid  painless
swelling in neck, may form fistula

171. DESCRIBE THE DEVELOPMENTAL BASIS OF
ECTOPIC PARATHYROID GLANDS
 Because of their extensive migrations during early embryogenesis, parathyroid
glands and components of the thymus gland are often found in abnormal sites.
Ectopic thymic tissue is typically found in the neck; ectopic inferior parathyroid
glands are often found either at the carotid bifurcation or in the superior
mediastinum.

172. LIST THE PRIMARY CHARACTERISTICS OF
CATCH-22 SYNDROMES AND RELATE THESE TO
PHARYNGEAL ARCH DEVELOPMENT &
DIFFERENTIATION.
 CATCH is the acronym for the sx seen in syndromes involving Chromosome 22 deletions.
These symptoms are associated with malformation of Neural Crest Cell derived tissues of
the 3rd and 4th pharyngeal arches
 C: cardiac defects
 A: abnormal facies
 T: thymic aplasia causes immune problems
 C: cleft palate
 H: hypocalcemia secondary to parathyroid aplasia
 Chromosome 22q11 (small arm of 22) deletion syndromes:
 DiGeorge Syndrome
 Velocardiofacial Syndrome
 Conotruncal Anomaly Face Syndrome

173. IDENTIFY THE SPINAL NERVES THAT FORM THE
CERVICAL PLEXUS AND THEIR CUTANEOUS
BRANCHES.
 Cervical Plexus is formed by: Ventral Primary Rami of C1 - C4 Spinal Nerves
 C1: Lesser Occipital Nerve
 C2: Great Auricular Nerve
 C3: Transverse Cervical Nerve
 C4: Supraclavicular Nerve
 “Sometimes considered part of the cervical plexus”: C5: Phrenic Nerve
 Innervation:
 neck muscles derived from ventral dermomyotomes of cervical somites
 skin of anterior and lateral neck
 portion of the face and shoulder

174. DESCRIBE THE ACTION OF THE
STERNOCLEIDOMASTOID MUSCLE (WHEN
ACTING BOTH UNILATERALLY AND
BILATERALLY) AND IDENTIFY ITS INNERVATION.
 Sternocleidomastoid:
 Origin: sternum + medial ⅓ of clavical; Inserts: mastoid process
 Action: to see it: http://www.youtube.com/watch?v=4ueRbHZh4js
 Unilaterally: tilts the head to the same side while rotating the face in the
opposite direction
 Bilaterally: flex cervical spine to bring the chin towards the manubrium
 Innervation: Cranial Nerve XI: Spinal Accessory Nerve

175. DEFINE TORTICOLLIS AND DESCRIBE ITS
TYPICAL PRESENTATION.
 Torticollis (“twisted neck”):
 Contraction or shortening of the cervical muscles, often congenital
 Produces a twisting of the head and slanting of the head
 Typical presentation: at birth due to fibrous tissue tumor in the SCM m.
 “The most common type of congenital torticollis results from a fibrous tissue
tumor that develops in the sternocleidomastoid muscle before or shortly after
birth. When torticollis occurs prenatally, the abnormal position of the infant’s
head usually necessitates a breech delivery.”
 Head tilted laterally towards muscle and rotated to opposite side.

177. IDENTIFY WHERE IN THE NECK THE SPINAL
ACCESSORY NERVE CAN BE INJURED AND THE
FUNCTIONAL DEFICITS EXPECTED WITH THIS
INJURY.
 The Spinal Accessory Nerve crosses through the Posterior (Occipital) Triangle
of the neck
 Expected deficits due to CN XI injury:
 Paralysis of trapezius
 impossible to abduct arm past 90 degrees
 can’t shrug shoulders
 Also innervates sternocleidomastoid
 so.. can’t/weaker flexion of cervical spine or lateral bending of cervical
spine.

179. POSTERIOR TRIANGLE OF NECK
 Borders:
 Anterior: Posterior border of the SCM
 Posterior: Anterior border of the trapezius muscle
 Inferior: Middle 1/3 of the clavicle
 Posterior triangle is further divided into “occipital” and “supraclavicular” triangles by
the inferior belly of the omohyoid muscle
 Contents
 Spinal accessory nerve
 Phrenic nerve
 Cervical plexus cutaneous branches
 External jugular vein
 Subclavian artery

180. ANTERIOR TRIANGLE OF NECK
 Anterior border of the sternocleidomastoid muscle
 Anterior midline of the neck
 Inferior border of mandible.
 Anterior triangle is further divided into:
 “Muscular” (containing the “infrahyoid” muscles),
 “Submandibular” (between the anterior and posterior digastric muscles and
the inferior border of the mandible and containing the submandibular gland)
 “Submental” (between the right and left anterior digastric muscles, inferior to
the chin)
 “Carotid” triangles.

181. INFRAHYOID MUSCLES
 Sternohyoid
 Sternothyroid
 Thyrohyoid
 Omohyoid
 Note that the omohyoid muscle consists of superior and inferior bellies.

182. SUPRAHYOID MUSCLES
 Anterior belly of digastric muscle
 Mylohyoid muscle
 The mylohyoid muscle marks the boundary between the oral cavity and
neck. Structures located superior to the mylohyoid muscle are located in the
oral cavity; structures located inferior to the mylohyoid are located in the
neck.
 Deep to submandibular gland
 Posterior digastric
 Stylohyoid

183. THE CAROTID SHEATH
 Internal jugular
 Common carotid
 Vagus nerve
 Sympathetic chain is located posterior to carotid sheath

184. IDENTIFY THE VERTEBRAL LEVELS OF THE
FOLLOWING PALPABLE STRUCTURES OF THE
NECK: SUPERIOR BORDER OF THE THYROID
CARTILAGE, CRICOID CARTILAGE.
 Superior border of thyroid cartilage – lies opposite the C5 vertebra
 Cricoid cartilage – located at level of C6 vertebra
 - Marks transition between larynx/trachea (respiratory) and pharynx/esophagus
(digestive)

185. STELLATE GANGLION BLOCK
 Stellate Ganglion Nerve Block – injection of anesthetic into sympathetic tissue
 Done above stellate ganglion with enough anesthetic to spread up and down
sympathetic trunk
 - relieve vasoconstriction after frostbite or microsurgery of hand
 - Treat Reynaud phenomenon (reduced blood to toes and fingers because of
cold temperatures or emotional stress) and hyperhydrosis (excessive
sweating) of the hand
 Needle insertion between trachea medially and sternocleiomastoid and
common carotid laterally using cricoid cartilage as a landmark.
 If successful, the following occurs:
 Vasodilation – blood vessels of head, neck, upper limb
 Horner syndrome: Miosis, Ptosis, Hemianhydrosis

186. CERVICAL PLEXUS BLOCK
 Cervical plexus nerve block – needle inserted at vertebral level C3
 USE: superficial surgery on neck or thyroid gland, pain management
 Landmark: line connecting mastoid process to transverse process of C6
 *Note: enough anesthetic injected to spread up and down here too

187. IDENTIFY THE TRANSVERSE LEVEL OF THE
CAROTID BIFURCATION IN THE NECK AND THE
SURFACE LANDMARK USED TO LOCATE IT.
 Bifurcation of the common carotid artery
 Common carotid --> internal and external carotid
 Occurs in anterior triangle of the neck at level of C5
 Superior border of thyroid cartilage
 Surface landmark: thyroid cartilage*

188. DISTINGUISH THE FUNCTIONS OF THE CAROTID
SINUS AND CAROTID BODY.
 Carotid sinus – pressure receptor, sensory information carried by CN IX and
CN X
 Carotid body – oxygen chemoreceptor, info also carried by CN IX and CN X

189. IDENTIFY WHERE IN THE NECK THE CAROTID
PULSE CAN BE PALPATED AND DISCUSS
POTENTIAL COMPLICATIONS OF THIS
PROCEDURE.
 Carotid pulse – palpated at superior border of thyroid cartilage (C5)
 Complication: Pressure on carotid sinus can cause reflex drop in blood
pressure and HR Palpation should be somewhere inferior to superior border of
thyroid cartilage
 Most clinicians prefer to use cricoid cartilage (C6).
 When taking the carotid pulse in the neck, the common carotid artery is
compressed against the enlarged anterior tubercle of the C6 vertebra. For this
reason, this tubercle is referred to as the carotid tubercle.

190. VERTEBRATE PROMINENS
 When the neck is fully flexed, the long spinous process of the C7 vertebra
projects more than that of nearby vertebra and can therefore be easily
recognized. For this reason the C7 vertebra is known clinically as the vertebra
prominens.

191. LIST THE THREE LAYERS OF THE DEEP
CERVICAL FASCIA AND THE FOUR CERVICAL
COMPARTMENTS THEY DEFINE. DEFINE THE
"BUCCOPHARYNGEAL FASCIA" AND DESCRIBE
ITS LOCATION.
 Prevertebral – surrounding cervical spine and muscles associated with it
 Pretracheal – surrounding viscera of neck (larynx/trachea, pharynx/esophagus)
and thyroid gland
 Buccopharyngeal fascia – portion of pretracheal fascia located posterior to
wall of pharynx
 Investing – outermost layer of deep cervical fascia (invests parotid gland,
submandibular gland, sternocleidomastoid, and trapezius)

192. FASCIA

193. IDENTIFY THE LAYERS OF THE DEEP CERVICAL
FASCIA THAT BOUND THE RETROPHARYNGEAL
SPACE. DESCRIBE THE CLINICAL SIGNIFICANCE
OF THIS SPACE.
 Retropharyngeal space
 buccopharyngeal fascia anteriorly
 paravertebral fascia posteriorly
 Clinical significance
 Chief avenue for spread of infection from the mouth, the nose, and the throat
to the medastinum of the thorax
 Difficulties in breathng, compression of esophagus, can spread to heart!

194. LIST THE STRUCTURES ENCLOSED WITHIN THE
CAROTID SHEATH
 Carotid artery
 Internal jugular vein
 Vagus Nerve

195. DISTINGUISH A CRICOTHYROIDOTOMY FROM A
TRACHEOSTOMY. IDENTIFY THE STRUCTURES AT
POTENTIAL RISK OF INJURY IN TRACHEOSTOMY.
 Cricothyroidotomy
 incision made in the median cricothyroid ligament
 used to quickly establish a temporary airway due to the absence of major
vessels in this location
 only used in emergencies because you may accidentally injure the vocal
folds
 Tracheostomy
 Tube insterted between 2nd and 3rd rings of tracheal cartilage.
 Structures at potential risk of injury:
 Inferior thyroid veins
 Thyroid ima artery
 Thmus gland in infants

196. DESCRIBE THE TYPICAL LOCATIONS OF THE
SUPERIOR AND INFERIOR PARATHYROID
GLANDS.
 Superior and inferior parathyroid glands
 internal to the connective tissue sheath of the thyroid gland, on the posterior
surface of each lobe
 Arterial supply: inferior thyroid artery

197. ARTERIAL SUPPLY OF THYROID GLAND
 External carotid  superior thyroid artery
 Subclavian  thyrocervical trunk  inferior thryoid artery
 Ima artery
 Venous drainage to superior, middle, inferior thyroid veins  IJV
 Recurrent laryngeal nerves run along posterior surface

199. IDENTIFY THE BRAIN STRUCTURES IMPORTANT
FOR LANGUAGE
 Transverse gyri of heschl: primary auditory cortex
 Supramarginal and angular gyrii of inferior parietal lobe: Wernicke’s area
 Pars triangularis and pars opercularis of inferior frontal gyrus: Broca’s area
 All supplied by MCA

201. SUBSTANTIA NIGRA
 Midbrain structure where dopaminergic neurons are localized
 The substantia nigra is visible, just dorsal to the cerebral.
 The substantia nigra has a ventral portion called the substantia nigra pars
reticulata, which contains cells very similar to those of the internal segment
of the globus pallidus. The internal segment of the globus pallidus and the
substantia nigra pars reticulata are separated from each other by the internal
capsule, in much the same way that it separates the caudate and putamen.
 The more dorsal substantia nigra pars compacta contains the darkly
pigmented dopaminergic neurons that give this nucleus its name.
Degeneration of these dopaminergic neurons is an important pathogenetic
mechanism in Parkinson’s disease.

203. STRIATUM
 The caudate and putamen are histologically and embryologically closely related
and can be thought of as a single large nucleus called the striatum.
 The striatum receives virtually all inputs to the basal ganglia.
 The caudate and putamen are separated by penetrating fibers of the internal
capsule but remain joined in some places by cellular bridges. The cellular
bridges appear as stripes, or striations, connecting the caudate and putamen in
histological sections, giving rise to the name “striatum.”

204. LENTIFORM NUCLEUS
Medial to the putamen lies the globus pallidus (or pallidum), meaning “pale
globe,” so named because of the many myelinated fibers traversing this region.
The globus pallidus has an internal segment and an external. The putamen and
globus pallidus together are called the lenticularorlentiform (meaning “lentil- or
lens-shaped”) nucleus.

206. THE CAUDATE AND THALAMUS ARE ALWAYS
MEDIAL TO THE INTERNAL CAPSULE, WHILE
THE LENTIFORM NUCLEUS (PUTAMEN AND
GLOBUS PALLIDUS) IS ALWAYS LATERAL TO THE
INTERNAL CAPSULE

208. The fornix is an axon tract which carries fibers
from the hippocampus to the hypothalamus.
The hippocampal commissure carries axons
connecting the left and right hippocampal
formations.

209. Bilateral internal cerebral veins join
with basal veins to form the great
cerebral vein (of Galen) posterior to
the pineal gland. These veins are all
part of the brain’s deep venous
drainage. The pineal gland is a
melatonin-producing endocrine gland
which regulates circadian rhythm.

211. STATE THE STRUCTURES THAT FORM THE
LATERAL WALLS AND THE FLOOR OF THE THIRD
VENTRICLE.
 Lateral walls of the third ventricle are formed by the thalamus and
hypothalamus
 The floor is formed by the optic chiasm, the mammillary bodies, the
infundibulum and the tuber cinereum
 The tuber cinereum is a hollow eminence of gray matter situated between the
mammillary bodies and the optic chiasm. The tuber cinereum is part of the
hypothalamus. Infundibulum and infundibular stalk (of the brain) are alternative
names for the pituitary stalk, the connection between the hypothalamus and the
pars nervosa hypophyseos

212. IDENTIFY THE AMYGDALOID BODY AND STATE
ITS FUNCTIONAL SIGNIFICANCE.
 Large rounded mass of gray matter in the anterior part of the temporal horn. It
is continuous with the medial cortex of the temporal lobe in the region of the
uncus. Although it is sometimes included with basal ganglia, the amygdaloid
body is functionally a key structure in the limbic system, which include functions
such as emotional reactions, decision making, and memory.

213. DISTINGUISH BETWEEN THE FIBER TRACTS
THAT TRAVEL IN THE ANTERIOR LIMB AND THE
POSTERIOR LIMB OF THE INTERNAL CAPSULE.
NAME THE FIBER TRACTS THAT TRAVEL IN THE
GENU OF THE INTERNAL CAPSULE.
 Anterior Limb: Part of the internal capsule located between the lentiform nucleus
laterally and the head of the caudate medially. Contains the frontal corticopontine as
well as the fibers connecting the thalamus and frontal cortex (anterior thalamic
radiation)
 Posterior Limb: Separates the thalamus on the medial side of the lentiform nucleus
on the lateral side. Contains the corticospinal tract (pyramidal tract), sensory
radiation, the corticopontine and the corticoreticular systems as well as thalamic
radiation.
 Genu: Located between anterior and posterior limb. Contains corticobulbar fibers

217. SYLVIUS STRUCTURES
 Corpus callosum
 Anterior horn of the lateral ventricle
 Posterior horn of the lateral ventricle
 Temporal (inferior) horn of the lateral ventricle
 Hippocampus
 Fornix
 Hippocampal commissure
 Pineal body
 Superior and inferior colliculi
 Thalamus (internal medullary lamina and pulvinar) Caudate nucleus (head and tail)
 Lentiform nucleus (external capsule, claustrum, extreme capsule, patamen, globus
pallidus)
 Striatum (putamen and head of caudate) Amygdaloid body
 Internal capsule (anterior and posterior limb)

220. IDENTIFY THE BONES THAT FORM THE ROOF,
LATERAL WALL, MEDIAL WALL AND FLOOR OF
THE BONY ORBIT.
 roof = frontal bone and lesser wing of sphenoid bone
 lateral wall = zygomatic bone and greater wing of sphenoid bone
 medial wall = ethmoid bone and lacrimal bone
 floor = maxillary bone and palatine bone

221. WHAT STRUCTURES PASS THROUGH THE
SUPERIOR ORBITAL FISSURE AND SUPERIOR
ORBITAL FORAMEN
 Superior Orbital Fissure:
 oculomotor nerve (cranial nerve [CN] III),
 trochlear nerve (CN IV),
 ophthalmic nerves (branches of the ophthalmic division of the trigeminal
nerve [CN V1),
 abducens nerve (CN VI), and
 superior ophthalmic vein
 Superior orbital foramen
 supraorbital branch of opthalmic nerve,
 supraorbital artery, and
 superior ophthalmic vein

222. WHAT STRUCTURES PASS THROUGH THE
INFERIOR ORBITAL FISSURE AND INFERIOR
ORBITAL FORAMEN
 Inferior Orbital Fissure:
 infraorbital nerve and zygomatic nerve (branches of the maxillary n. = CN
V2),
 infraorbital artery
 Inferior Orbital Canal/Foramen (Infraorbital Foramen and Groove):
 infraorbital nerve,
 infraorbital artery
 Inferior opthalmic vein

223. IDENTIFY THE STRUCTURES THAT PASS
THROUGH THE OPTIC CANAL AND
NASOLACRIMAL CANAL
 Optic Canal:
 optic nerve (CN II) and
 ophthalmic artery (a branch of the internal carotid artery).
 Nasolacrimal Canal:
 nasolacrimal duct from the lacrimal sac to the inferior nasal meatus.

224. THE INFERIOR ORBITAL FISSURE IS
CONTINUOUS WITH…
 Pterygopalatine fossa
 This space is also continuous with the foramen rotundum
 The infraorbital and zygomatic branches of the maxillary nerve enter the
posterior aspect of the orbit from the pterygopalatine fossa.

225. IN WHAT AREAS IS THE ORBITAL WEAK?
 The medial and inferior walls of the orbit are thin due to the adjacent ethmoidal
air cells and maxillary sinus, respectively
 Because the margins of the orbit are significantly stronger than its walls, blows
to the orbit may result in either a separation and displacement of bones at
sutures, or a fracture of one or more of its walls (“blowout” fracture). Fractures
of the medial wall may involve the ethmoid or sphenoid sinuses; fractures of the
inferior wall may affect the maxillary sinus and infraorbital nerve. Extra-ocular
muscles can also get trapped within the broken orbital walls.

226. ORBITAL SEPTUM
 The orbital septum is a
fibrous membrane that
passes from the tarsal plates
to the margins of the orbit
 Can limit spread of infection
or confine infection to orbit

227. DEFINE PAPILLEDEMA & IDENTIFY ITS
ANATOMICAL BASIS.
 A noninflammatory edema of the optic disc (papilla) due to increased
intracranial pressure usually caused by brain tumors, subdural hematoma, or
hydrocephalus. It usually does not alter visual acuity, but may cause bilateral
enlarged blind spots.

228. EXTRAOCULAR MUSCLES
 Levator palpebrae superioris: CN III, Elevates upper eyelid
 Superior Oblique: CN IV Depresses, abducts, intorts
 Inferior Oblique: CN III Elevates, abducts, extorts
 Superior Rectus: CN III Elevates, adducts, intorts
 Medial Rectus: CN III Adducts
 Inferior Rectus: CN III Depresses, adducts, extorts
 Lateral Rectus: CN VI Abducts

229. IDENTIFY WHERE THESE NERVES ARE
VULNERABLE AND DESCRIBE THE FUNCTIONAL
DEFICITS ASSOCIATED: CN III, CN IV AND CN VI.
 CN III (down and out)
 Aneurysm of the posterior cerebral or superior cerebellar arteries
 Cavernous sinus infections
 Rapidly increasing intracranial pressure often compresses CN III against petrous temporal
 Functional deficit: interruption of motor to EOM and levator palpebrae superioris; interruption of
preganglionic parasympathetic nerve fibers to ciliary ganglion
 CN IV (vertical diplopia, head turned due to extorsion)
 Rarely paralyzed alone
 Cavernous sinus infections
 Functional deficit: interruption of motor to superior oblique
 CN VI (affected eye is deviated medially)
 Stretched when intracranial pressure rises
 Space occupying lesion within the cranial cavity (tumor) may compress nerve
 Often first nerve affected in cavernous sinus infections
 Functional deficit: interruption of motor to lateral rectus

230. LIST THE THREE LAYERS (COATS, TUNICS) OF
THE EYEBALL. IDENTIFY THE COMPONENTS OF
THE CORNEOSCLERAL (OUTER) AND UVEAL
(MIDDLE) TUNICS
 Corneoscleral Tunic (tunica fibrosa)
 Cornea : avascular structure highly innervated by branches of CN V1
 Sclera: white, opaque structure that provides attachments for the extraocular eye
muscles
 Corneoscleral Junction (limbus) : junction of the transparent cornea and the opaque
sclera
 contains a trabecular network and the canal of schlemm, which are involved in the
flow of aqueous humor
 Uveal Tunic (tunica vasculosa)
 Choroid : pigmented vascular bed that lies immediately deep to the corneoscleral tunic
 Stroma of the ciliary body: ciliary muscle is circularly arranged around the entire
circumference of the ciliary body and is innervated by the parasympathetic nervous
system
 Stroma of the iris: contains the dilator pupillae muscle and sphincter pupillae muscle
 Retinal Tunic (neural coat)

231. THE VESSELS OBSERVED ON THE ANTERIOR OF
ASPECT OF THE SCLERA LIE WITHIN WHAT
LAYER?
 The conjunctiva

232. LEVATOR PALPEBRA SUPERIORIS
 Insertion: superior tarsal plate
 Action: elevates upper eyelid and opens palpebral fissure
 Innervation: CN III
 Third nerve palsy*

233. SUPERIOR TARSAL MUSCLE
 Stretches between the levator palbebrae superioris tendon and the superior
tarsal plate. This small slip of smooth muscle assists the levator palpebrae
superioris in elevating the upper eyelid.
 Loss of function of the superior tarsal muscle (via loss of sympathetic input)
results in a partial ptosis of the upper eyelid. Loss of sympathetic output will
further result in a pin-point pupil due to loss of function of the dilator pupillae

234. WHAT ARE THE TWO THIN MUCOUS
MEMBRANES THAT COVER THE INSIDE OF THE
EYELIDS AND THE SURFACE OF THE EYE?
 Palpebral conjunctiva
 Bulbar conjunctiva
 Contains small visible blood vessels
 Form conjunctival sac
 Conjunctivitis is inflammation of the conjunctiva
 Can be dangerous w/ N. gonorrhea or C. trachomatis
 CORNEA IS AVASCULAR

235. LIST THE STRUCTURES OF THE EYE THAT CAN
BE OBSERVED WITH AN OPHTHALMOSCOPE.
 Fundus of the eye (retina, optic disc, macula, fovea, posterior pole).
 Optic disc will be on medial/nasal side, allowing you to distinguish which eye is
being viewed

236. IS THE MACULA NASAL OR TEMPORAL TO THE
OPTIC DISC?
 Temporal

237. LIST THE TWO MUSCLES OF THE IRIDIAL
STROMA AND IDENTIFY THEIR FUNCTIONS.
IDENTIFY THE DIVISION OF THE AUTONOMIC
NERVOUS SYSTEM RESPONSIBLE FOR
INNERVATING EACH.
 Dilator pupillae muscle = pupil dilation; sympathetic innervation
 Sphincter pupillae muscle = pupil constriction (miosis); parasympathetic
innervation

238. ACCOMMODATION
• Close vision: ciliary
muscle contracts,
zonulus fibers relax,
lens becomes
rounder.
• Distant vision: ciliary
muscle relaxes, more
tension on zonulus
fibers, lens becomes
flatter.

239. DESCRIBE THE DEVELOPMENTAL BASIS OF
CYCLOPIA AND COLOBOMA.
 Coloboma:
 Normally, choroid fissure allows passage of hyaloid artery to eye and then fuses during
7th week of development
 Failure of choroid fissure to fuse completely (can occur at the level of the iris, retina, or
optic nerve) causes coloboma
 Correlates strongly with congenital heart defects
 Cyclopia
 Prechordal mesoderm is essential for division of a single primordial eye field into two
separate eye fields
 Expression of Pax6 (“eye selector”) gene gives rise to development of eye field
 Prechordal mesoderm signaling suppresses Pax6 signaling in midline of single primordial
eye field, dividing it into two
 Disruption signaling causes incorrect spacing of eyes or birth with a single eye =
hypotelorism/holoprosencephaly/cyclopia
 Also prevents descent of nose between the eyes, causing a superiorly displaced proboscis

240. DESCRIBE THE DEVELOPMENTAL FATES OF THE
LENS PLACODE, INNER AND OUTER LAYERS OF
THE OPTIC CUP AND THE HYALOID ARTERY.
 Fate of the Optic Cup
 Outer layer → pigmented layer of the retina
 Inner layer → neural layer of the retina
 Hyaloid artery → central artery of the retinas
 Lens placode → lens vesicle

241. DESCRIBE THE FUNCTIONS OF THE FOLLOWING
TARSAL GLANDS, CONJUNCTIVAL SAC,
EYELASHES, CILIARY GLANDS.
 Tarsal glands (aka meibomian glands) = The lipid secretions of the tarsal glands
reduce surface tension, which has the effect of preventing the spilling of lacrimal fluid
out of the eyelids.
 Conjunctival sac = the space formed between the palpebral and the bulbar
conjunctiva
 specialized form of mucosal bursa that enables the eyelids to move freely
(frictionless) over the surface of the eye as they open and close
 Eyelashes = hairs on the edge of the eyelid that prevent debris from contacting the
eye and provide sensitive mechanoreceptive feedback to protect the eye.
 Ciliary glands = modified apocrine sweat glands found on the margin of the eyelid;
empty into adjacent lashes, adding lipid content to tear film, thus reducing
evaporation.

242. DESCRIBE THE CORNEAL REFLEX AND IDENTIFY
ITS AFFERENT (SENSORY) AND EFFERENT
(MOTOR) LIMBS.
 Corneal reflex = involuntary blinking of the eyelids when the cornea is
stimulated/touched OR when there’s noise greater than 40-60 dB (protective)
 Afferent/sensory limb: CN V1 (ophthalmic branch of trigeminal)
 Efferent/motor limb: CN VII (Facial nerve – temporal and zygomatic
branches)

244. DESCRIBE THE FUNCTION OF THE FOLLOWING
STRUCTURES: LACRIMAL GLANDS, LACRIMAL
CANALICULI, LACRIMAL SAC, NASOLACRIMAL
DUCT
 Lacrimal glands: located in the superior lateral aspect of each orbit and secrete
lacrimal fluid
 Lacrimal canaliculi: drains the tears from the surface of the eye
 Lacrimal sac: connects the lacrimal canaliculi to the nasolacrimal duct
 Nasolacrimal Duct: conveys lacrimal fluid into the nasal cavity; it is transmitted
via the nasolacrimal canal and it goes from the lacrimal sac to the inferior nasal
meatus.

245. GREATER PETROSAL NERVE AND
PTERYGOPALATINE GANGLION.
 Greater Petrosal Nerve: (branch of CN VII) innervates the lacrimal glands;
carries preganglionic parasympathetic fibers to the pterygopalatine ganglion
which then sends fibers to the lacrimal gland via the maxillary and opthalmic
nerves.
 Pterygopalatine ganglion: area where the preganglionic axons from the superior
salivary nucleus and the lacrimal nucleus (which run with CN VII) enter and
then synapse with the postganglionic parasympathetic neurons. These
postganglionic parasympathetic neurons then leave the pterygopalatine
ganglion and run with the zygomaticofacial branch of CN V2 and the lacrimal
branch of CNV1 to innervate the lacrimal gland.

246. DESCRIBE THE FLOW OF LACRIMAL FLUID AND
THE ROLE OF BLINKING IN THIS PROCESS. LIST
THE POTENTIAL COMPLICATIONS OF DRY EYE.
 Lacrimal glands make lacrimal fluid → flows through excretory ducts into
conjunctival sac → fluid gathers in the lacrimal lake → gets drawn into puncta
by capillary action → flows through lacrimal canaliculi at inner corner of eyelids
→ enters lacrimal sac → nasolacrimal duct → nasal cavity (inferior nasal
meatus)
 Blinking helps spread lacrimal fluid over the surface of the eye.
 Complications of dry eye: Ulcers, risk of eye infections; eye inflammation →
scarring and vision problems; makes it hard to do regular activities.

248. LIST THE THREE SUBDIVISIONS OF THE
PHARYNX AND IDENTIFY THEIR ANATOMICAL
BOUNDARIES
 Nasopharynx, oropharynx, laryngopharynx (hypopharynx)
 When elevated against the posterior pharyngeal wall during swallowing, the soft
palate and uvula distinguish the nasopharynx above from the oropharynx
below.
 The paired palatoglossal folds mark the transition from oral cavity to
oropharynx.
 The larynx is located between the laryngeal inlet and the inferior border of the
sectioned cricoid cartilage.
 The laryngopharynx (hypopharynx) is that portion of the pharynx located
posterior to the laryngeal inlet and larynx

250. IDENTIFY THE MUSCLES THAT FORM THE
ANTERIOR AND POSTERIOR PILLARS OF THE
TONSILLAR FOSSA
 Palatoglossal
 Palatopharyngeus

251. DESCRIBE HOW TO ELICIT THE GAG REFLEX
AND IDENTIFY ITS AFFERENT AND EFFERENT
LIMBS
 Stimulation of the glossopharyngeal nerve in the oropharyngeal isthmus elicits
the gag reflex, which is a reflex contraction of the palatoglossus and
palatopharyngeus muscles. Both of these muscles receive their motor input
from the vagus nerve.

252. COMPARE THE FLOW OF LYMPH FROM THE TIP
OF THE TONGUE WITH THAT OF MORE
POSTERIOR REGIONS OF THE TONGUE.
 Lymph from the lateral margins of the tongue, as well as the lateral aspects of
the lower lip, drain principally to the submandibular lymph nodes located inferior
to the body of the mandible.
 Lymph from the apex of the tongue, frenulum, and central portion of the lower
lip drains to the submental lymph nodes located inferior to the chin.
 Lymph from the central and posterior aspects of the dorsum of the tongue
drain principally to the jugulodigastric node – the largest member of the
superior group of the deep cervical chain.

253. LIST THE THREE PAIRS OF SALIVARY GLANDS
AND INDICATE WHERE IN THE ORAL CAVITY
EACH DRAINS
 Sublingual - drains into the sublingual fold in the floor of the mouth
 Submandibular - drains on the frenulum of the tongue
 Parotid - drains into the roof of the oral vestibule lateral to the 2nd maxillary
molar

254. IDENTIFY THE PARASYMPATHETIC GANGLION
THAT PROVIDES SECRETOMOTOR INNERVATION
TO THE PAROTID GLAND. IDENTIFY THE CN THAT
SUPPLIES THE PRESYNAPTIC FIBERS.
 Otic Parasympathetic Ganglion provides secretomotor innervation to the
parotid gland
 Glossopharyngeal nerve (CN IX) provides presynaptic fibers to the otic
parasympathetic ganglia.

256. IDENTIFY THE PARASYMPATHETIC GANGLION
THAT INNERVATES THE SUBMANDIBULAR AND
SUBLINGUAL GLANDS. IDENTIFY THE BRANCH
OF THE FACIAL NERVE THAT SUPPLIES THE
PRESYNAPTIC FIBERS
 The Submandibular parasympathetic ganglia provide secretomotor innervation
to the submandibular and sublingual glands
 The Chorda Tympani branch of the Facial Nerve supplies the presynaptic fibers
to the submandibular parasympathetic ganglia.

258. TRIGEMINAL NERVE
 The trigeminal nerve exits the brainstem from the ventrolateral pons.
 The ophthalmic division (V1) travels through the inferior part of the cavernous
sinus to exit the skull via the superior orbital fissure. The maxillary division (V2)
exits via the foramen rotundum and the mandibular division (V3) via the
foramen ovale.
 Sensory: Sensation for the face, mouth, anterior two-thirds of the tongue, nasal
sinuses, and supratentorial dura.
 Motor (V3): Muscles of mastication: masseter, temporalis, med./lat. Pterygoid
m.
 Zygomatic n (V2): postganglionic parasympathetic fibers from pterygopalatine
ganglion to lacrimal gland
 Auricolutemporal n (V3): postganglionic fibers to parotid gland

259. FACIAL NERVE
 Facial nucleus is located more caudally than the trigeminal nucleus in the pons.
 Nerve exits at the pontomedullary junction, and enters the internal auditory
meatus to travel in the petrous temporal bone with CN VIII.
 Geniculate ganglion: taste sensation in the anterior 2/3 of the tongue, and
general somatic sensation near the external auditory meatus.
 Motor: exits the skull at the stylomastoid foramen, passes through the parotid
gland and divides into five major branchial motor branches: temporal,
zygomatic, buccal, mandibular, and cervical.
 Other smaller branchial motor branches innervate the stapedius, occipitalis,
posterior belly of the digastric, and stylohyoid muscles.
 Greater petrosal: preganglionic fibers to pterygopalatine ganglion
 Chorda tympani: preganglionic fibers with lingual n. (V3) to submandibular
ganglion

260. GLOSSOPHARYNGEAL NERVE
 Exits the brainstem as several rootlets along the upper ventrolateral medulla,
just below the pontomedullary junction and just below CN VIII, between the
inferior olive and the inferior cerebellar peduncle
 Exits skull via jugular foramen
 Sensory: sensation of touch, pain, and temperature from the posterior one-third
of the tongue, pharynx, middle ear, and a region near the external auditory
meatus
 Taste: posterior 1/3 of tongue
 Motor: stylopharyngeus m.  Gag reflex
 Lesser petrosal n.: Parasympathetic preganglionic fibers to otic ganglion
(parotid)

261. DISTINGUISH THE EXTERNAL NOSE FROM THE
INTERNAL NOSE. DISTINGUISH THE ANTERIOR
NARES FROM THE POSTERIOR CHOANAE.
 The external nose projects from the face.
 The internal nose is contained within the bones of the skull.
 The anterior nares are the external portion of the nostrils; they open into the
nasal cavity and allow the inhalation and exhalation of air (wiki)
 The posterior choanae are the openings into the nasopharynx from the nasal
cavities

262. LIST THE THREE COMPONENTS OF THE NASAL
SEPTUM.
 Perpendicular plate of ethmoid bone
 Vomer
 Septal nasal cartilage

263. IDENTIFY WHERE THESE STRUCTURES OPEN
INTO THE NASAL CAVITY: FRONTAL SINUS,
ANTERIOR, MIDDLE AND POSTERIOR ETHMOID
AIR CELLS, SPHENOID SINUS, MAXILLARY
SINUS, NASOLACRIMAL DUCT
 Posterior ethmoid air cells → superior meatus
 Sphenoid sinus → sphenoethmoidal recess
 Anterior ethmoid air cells → semilunar hiatus in the middle meatus
 Frontal sinus → semilunar hiatus in the middle meatus
 Maxillary sinus → semilunar hiatus in the middle meatus
 Middle ethmoid air cells → ethmoidal bulla in middle meatus
 Nasolacrimal duct from the eye → inferior meatus

264. IDENTIFY THE BRANCH OF THE TRIGEMINAL
NERVE THAT PROVIDES SENSORY INNERVATION
TO THE FOLLOWING STRUCTURES: FRONTAL
SINUS, MAXILLARY SINUS, ETHMOIDAL AIR
CELLS, SPHENOID SINUS.
 Frontal sinus: Ophthalmic branch of trigeminal (CN V1)
 Ethmoidal air cells: Ophthalmic branch of trigeminal (CN V1)
 Sphenoid sinus: Ophthalmic branch of trigeminal (CN V1)
 Maxillary sinus: Maxillary branch of trigeminal (CN V2)

265. DESCRIBE THE LOCATION OF THE OLFACTORY
EPITHELIUM IN THE NOSE. REVIEW THE
RELATIONSHIP OF THE OLFACTORY NERVE (CNI)
TO THE CRIBRIFORM PLATE.
 Olfactory epithelium is present in the superior region of the lateral nasal wall
 The cribriform plate supports the olfactory bulb of CN I and has numerous
perforations (foramina) that allow for individual filaments of the olfactory nerve
to pass through to the nasal cavity.

266. DISTINGUISH THE AREAS OF THE LATERAL AND
MEDIAL NASAL WALLS INNERVATED BY
BRANCHES OF THE OPHTHALMIC, MAXILLARY
AND OLFACTORY NERVES.
 The opthalmic artery branches
into anterior and posterior
ethmoidal arteries. These supply
the anterior/superior portion of
the medial and lateral nasal
walls
 The maxillary artery branches
into the sphenopalatine artery,
which supplies the
posterior/inferior portion of the
medial and lateral nasal walls

267. DEFINE EPISTAXIS. DESCRIBE THE LOCATION OF
KIESSELBACH’S AREA IN THE NASAL CAVITY
AND IDENTIFY THE BRANCHES OF THE
EXTERNAL CAROTID ARTERY THAT CONTRIBUTE
 Epistaxis: bleeding from the nose (nosebleed)
 Kiesselbach’s area:
 Located along the anterior aspect of the nasal septum
 Area of extensive anastomosis between branches of the ophthalmic, maxillary,
and facial arteries

268. DEFINE RHINITIS AND LIST THE FIVE LOCATIONS
TO WHICH INFECTIONS OF THE NASAL CAVITIES
CAN SPREAD
 Rhinitis: swelling and inflammation of the nasal mucosa
 5 locations of spread:
 Anterior cranial fossa via the cribriform foramina
 Nasopharynx via the posterior choanae
 Middle ear via the auditory tube
 Paranasal sinuses (resulting in sinusitis)
 Lacrimal apparatus and conjunctiva via the nasolacrimal duct

269. IDENTIFY THE STRUCTURES POTENTIALLY
AFFECTED IN INFECTIONS OF THE ETHMOID
SINUSES.
 Dural sheath of optic nerve → optic neuritis
 Optic nerve in the optic canal → potential blindness
 Infections of the ethmoid sinuses (ethmoidal air cells) may break through the
fragile medial wall of the orbit. Spread of infection from these cells could affect
the dural sheath of the optic nerve, causing optic neuritis. If severe, infections
of the ethmoid sinuses can also cause blindness by spreading to the optic
nerve in the optic canal.

270. DESCRIBE THE ANATOMICAL BASIS FOR
MAXILLARY SINUS INFECTIONS.
 Clinicians usually refer to the maxillary sinus as the antrum (cavity or chamber).
Due to the high position of their drainage ostia (openings), drainage of the
maxillary air sinuses (antra) is impeded, which likely accounts for the high
incidence of maxillary sinus infections.

271. LIST THE FIVE (5) LYMPHATIC TISSUES THAT
FORM “WALDEYER’S RING” AND DESCRIBE
THEIR LOCATIONS.
 Both the nasopharynx and oropharynx are richly endowed with mucosa-associated
lymphoid tissue (MALT)
 Waldeyer’s Ring: aggregation of lymphoid tissues guarding the openings of the
digestive and respiratory tracts.
 Consists of palatine, lingual, pharyngeal, and tubal tonsillar tissues, MALT
tissue between tonsils

272. IDENTIFY THE STRUCTURES AT RISK OF INJURY
IN TONSILLECTOMY AND DESCRIBE THE
FUNCTIONAL DEFICITS THAT RESULT. DEFINE
ADENOIDITIS.
 A tonsillectomy risks injury to the Glossopharyngeal Nerve (CN IX)
 This nerve is the afferent nerve for the Gag Reflex, which receives motor
activation from the Vagus Nerve (CN X). Damage to CN IX would result in a
loss of the gag reflex.
 Adenoiditis: Inflammation of the Pharyngeal Tonsil.

273. DESCRIBE THE CLINICAL SIGNIFICANCE OF THE
“TONSILLAR” NODE OF THE DEEP CERVICAL
CHAIN.
 The “Tonsillar” node, officially known as the Jugulo-Digastric node is frequently
enlarged when the palatine tonsil is inflamed, and therefore signifies the
presence of tonsillitis.

274. DISTINGUISH THE TRUE VOCAL FOLDS FROM
THE FALSE VOCAL (VESTIBULAR) FOLDS
ANATOMICALLY.

275. SUPERIOR LARYNGEAL NERVE (CN X)
 Superior Laryngeal Nerve:
 Internal Branch: Sensory nerve
 Innervates the mucosa between the root of the tongue and the vocal cords.
 External Branch: Motor nerve
 Provides motor innervation to the cricopharyngeus and cricothyroid muscles.
 Cricothyroid muscle: only intrinsic muscle of the larynx innervated by the superior
laryngeal nerve.
 Cause of Injury:
 Puncture of the piriform recess by a sharp object lodged in the throat
 Damage to the superior laryngeal nerve can result when ligating the superior thyroid
artery during thyroidectomy
 Consequence:
 Weak voice with loss of projection, and the vocal cord on the affected side appears
flaccid
 Difficulty swallowing

276. RECURRENT LARYNGEAL NERVE (CN X)
 Sensory: larynx mucosa inferior to the vocal cords
 Motor: intrinsic laryngeal muscles (Except cricopharyngeus and cricothyroid)
 Cause of Injury:
 Thyroidectomy
 Consequence of injury:
 Unilateral damage to the recurrent laryngeal nerve can result from dissection
around the ligament of Berry or ligation of the inferior thyroid artery during
thyroidectomy. Results in hoarse voice, inability to speak for long periods,
and movement of the vocal fold on the affected side toward midline
 Bilateral damage to the recurrent laryngeal nerve results from same
processes during thyroidectomy but results in acute breathlessness
(dyspnea) since both vocal folds move toward the midline and close off the
air passage

277. DEFINE THE FOLLOWING TERMS RELATING TO
THE ANATOMY OF THE LARYNX: VESTIBULE,
VENTRICLE, GLOTTIS, RIMA GLOTTIDIS.
 Vestibule – the upper portion of the laryngeal cavity, just inferior to laryngeal
inlet, formed by the paired vestibular membranes
 Ventricle – space created between vestibular fold and vocal fold
 Glottis – space / plane that extends between the vocal ligaments.
Widens/closes with breathing, speech, etc.
 Rima glottidis – the rim around the vocal ligaments
 During swallowing/movement of vocal ligaments, you’re changing width of
rima glottidis

278. DESCRIBE THE FEATURES OF TREACHER
COLLINS SYNDROME AND FIRST ARCH
SYNDROMES. RELATE THESE TO MIGRATION
AND DEVELOPMENT.
 Treacher-Collins Syndrome
 A “first-arch syndrome” (or mandibulofacial dysostosis) - failure of neural
crest cells to properly migrate to first pharyngeal arch.
 Causes:
 Some forms are genetically-based (Treacher-Collins and Pierre Robin
Syndrome)
 Similar abnormalities also seen with retinoid administration in first month of
pregnancy
 Consequences: Congenital malformations of eyes, ears, mandible, and face

279. DESCRIBE THE EMBRYOLOGICAL BASIS OF
CLEFT LIP, CLEFT PALATE AND OBLIQUE FACIAL
CLEFTS.
 Caused by underdevelopment of the first pharyngeal arch mesenchyme:
 Mesenchyme is a type of undifferentiated loose connective tissue derived
mostly from mesoderm. In first arch syndrome, issue is with neural crest
cells, whereas with facial clefts, the issue lies in mesenchymal tissue.
 Lateral (oblique facial) clefts)
 incomplete fusion of the maxillary prominence with the lateral nasal process
in the cheek region = NASOLACRIMAL DUCT!!!!
 Cleft lip
 failure of the maxillary prominence to fuse with the intermaxillary segment
 Cleft palate
 failure of the two palantine shelves to fuse with each other along the midline.

280. DISCUSS THE SIGNIFICANCE OF DEGENERATION
OF THE ORONASAL MEMBRANE IN
DEVELOPMENT OF THE NASAL CAVITY.
 As the upper jaw and face take shape, the nasal pits continue to deepen.
 Initially, the nasal pits are completely separated from the developing oral cavity
by the oronasal membrane.
 Degeneration of this membrane establishes communication of the oral and
nasal cavities through the large primitive choanae.
 The primitive choanae are transformed into the definitive choanae upon
completion of secondary palate development.

281. EMBRYOLOGICAL ORIGIN OF THE PINNA,
MIDDLE EAR, TYMPANIC MEMBRANE, INNER
EAR, EXTERNAL AUDITORY CANAL AND
PHARYNGOTYMPANIC CANAL.
 First Pharyngeal arch
 Tympanic membrane
 External acoustic meatus
 Auditory tube
 Tympanic cavity
 Otic vesicle (otocyst)
 Inner ear
 (Membranous labyrinth including the utricle, saccule, semicircular ducts, cochlear duct,
sensory hair cells and ganglion cells. The bony labyrinth is formed by neural crest cells
that surround the otocyst)
 Auricular hillocks (6 swellings) that surround pharyngeal groove 1
 External ear (pinna).
 (3 of these hillocks are components of pharyngeal arch 1, the remaining three are
components of pharyngeal arch 2)

282. DESCRIBE THE DEVELOPMENTAL BASIS OF
BRANCHIAL CLEFT ABNORMALITIES TYPES I, II,
III AND IV
 Also known as lateral cervical cysts. When the cervical sinuses derived from the
pharyngeal grooves do not obliterate, they can fill with fluid and form cysts in the
neck. ALWAYS ANTERIOR TO STERNOCLEIDOMASTOID MUSCLE. In PRL, the
cysts labeled I, II, and III are actually derived from grooves 2,3, and 4.
Maldevelopment of the first groove will be seen around ear region as a preauricular
fistula or cyst.
 First cleft gives rise to external auditory canal. Abnormalities  recurrent ear
infections
 Second cleft forms epidermis of the dorsal half of the auricle and the upper neck.
Abnormalities are usually cervical  recurrent tonsillitis
 Third cleft abnormalities  abnormal thymic stalks/cysts (remember DiGeorge is
abnormal 3rd and 4th pouches and can cause thymic aplasia)
 Fourth cleft forms vagus nerve. Abnormalities  cough