General oto neck space anatomy Flashcards
What are the two primary fascia networks of the
neck?
Superficial cervical fascia and the deep cervical fascia
Describe the anatomy of the superficial cervical
fascia.
It lies just deep to the dermis and superficial to the deep
cervical fascia. It extends from the zygoma to the clavicle
and envelops the platysma and muscles of facial expression.
Describe the anatomy of the deep cervical fascia.
It is composed of the superficial (investing), middle (visceral
and muscular), and deep (prevertebral and alar) layer. The
carotid sheath fascia is created by all three layers of the
deep cervical fascia.
Describe the anatomy of the superficial (investing)
layer of the deep cervical fascia.
It surrounds the neck and inserts superiorly at the nuchal
ridge, mastoid, zygoma, and mandible and inferiorly at the
clavicles, sternum, scapula, and acromion. It envelops the sternocleidomastoid muscle, trapezius, muscles of masti-
cation, submandibular glands, and parotid gland. Inferiorly, its manubrial insertion splits to form the suprasternal space
of Burns.
Describe the anatomy of the middle (visceral and
muscular) layer of the deep cervical fascia.
It extends superior to the cranial base and inferiorly to the
upper mediastinum. It is subdivided into the muscular and
visceral layers. The muscular division surrounds the infra-
hyoid strap muscles; the visceral portion surrounds the pharyngeal constrictors, esophagus, trachea, and thyroid
and creates the buccopharyngeal fascia. Both divisions
contribute to the carotid sheath.
Describe the anatomy of the deep (prevertebral
and alar) layer of the deep cervical fascia.
It is subdivided into the alar and prevertebral fascia. Both extend superiorly from the cranial base, but the alar fascia fuses with the middle cervical fascia and extends into the upper mediastinum, and the prevertebral fascia extends to
the level of the coccyx. The alar fascia and prevertebral
fascia fuse at the vertebral transverse processes and after
joining, envelop the paraspinous muscles.
Describe the anatomy of the suprasternal space
space of Burns
The inferior insertion of the superficial (investing) fascia
splits just above the manubrium attaching anterior to the
manubrium and posteriorly to the interclavicular ligament.
This small potential space contains a portion of the anterior jugular veins, and the sternal heads of the sternocleido-
mastoid muscle.
Define the boundaries of the buccal space.
The buccal space is created by the buccinator muscle
medially; the superficial layer of the deep cervical fascia and
the muscles of facial expression laterally and anteriorly; and
the muscles of mastication, mandible, and parotid gland
posteriorly. It primarily contains adipose tissue (buccal fat
pad), minor salivary glands, accessory parotid tissue, and
facial/buccal arteries, veins, and lymphatics. The buccal fat
pad is pierced by the parotid duct as it courses to the
buccinator and eventually enters the mouth opposite the
second upper molar.
Define the mechanism of spread of infection (or
tumor) to and from the buccal space.
It permits spread between the mouth, parotid space, and masticator space from deficient fascial compartmentalization along the superior, inferior, and posterior limits.
Define the boundaries of the carotid space.
The carotid sheath contains the carotid artery, internal
jugular vein, vagus nerve, and jugular lymphatic chain. All
three divisions of the deep cervical fascia form the carotid
sheath. It extends from the skull base to the mediastinum;
anteriorly lies the sternocleidomastoid muscle, posteriorly
the prevertebral space, and medially the visceral compart-
ment.
Review the risk factors for carotid blowout.
Radiation, salivary fistula, malnutrition, hypothyroidism, T-
incision over the great vessels, radical neck dissection
Define the boundaries of the danger space.
The danger space is a potential space that rests between the
alar fascia and the prevertebral fascia. Infections in this area
can communicate with the thorax (mediastinum) to the
level of the diaphragm.
Define the boundaries of the masticator space.
The masticator space is created from the superficial layer of
the deep cervical fascia surrounding the masseter laterally
and the pterygoid muscles medially. It contains masseter muscle, pterygoid muscles, inferior tendon of the tempo-
ralis muscle, ramus, and posterior body of the mandible, internal maxillary artery, and the inferior alveolar neuro-
vascular bundle.
Define the boundaries of the parapharyngeal
space.
It is shaped as an inverted pyramid with the base at the
cranial base and the apex at the hyoid bone. Anteriorly, it is
bound by the pterygomandibular raphe, posteriorly be the
prevertebral fascia, medially by the superior pharyngeal
constrictor, and laterally by the parotid, mandible, and
lateral pterygoid.
How is the parapharyngeal space commonly
divided?
Prestyloid and poststyloid compartments are divided by the
tensor-vascular-styloid fascia connecting the tensor veli
palatini and the styloid process.
What structures are contained within the presty-
loid space?
Fat, lymph nodes, minor salivary gland tissue, internal
maxillary artery, and the inferior alveolar, auriculotemporal
and lingual nerves
What structures are contained within the post-
styloid space?
Carotid artery, internal jugular vein, cranial nerves 9
through 12, and the superior sympathetic chain
What is the syndrome that follows the para-
pharyngeal space or parotid surgery that causes pain with the onset of eating?
First-bite syndrome
Define the boundaries of the parotid space.
It is created by the superficial layer of deep cervical fascia as it surrounds the mandible and parotid gland and contains the parotid gland and parotid lymph nodes, the facial nerve, posterior facial vein, and facial artery.
Describe the mechanism of infection or tumor spread from the parotid space to the paraphar-
yngeal space.
The superomedial parotid space fascia is deficient, allowing
for direct spread into the parapharyngeal space via the
stylomandibular tunnel.
Define the boundaries of the peritonsillar space.
It is bound by the palatine tonsil medially and the superior
pharyngeal constrictor, palatoglossus, and palatopharyngeus
medially, superiorly, inferiorly, anteriorly, and posteriorly. It
contains loose areolar tissue and minor salivary glands.
Define the boundaries of the prevertebral space.
It extends from the skull base to the coccyx and is bordered
anteriorly by the prevertebral fascia, posteriorly by vertebral
bodies, and laterally by the transverse processes of
vertebrae.
Describe the sequential layers and spaces (super-
ficial to deep) of the posterior pharyngeal wall.
Mucosa, pharyngeal constrictor, buccopharyngeal fascia, retropharyngeal space, alar fascia, danger space, prevertebral fascia, prevertebral space
Define the boundaries of the sublingual space.
It contains the sublingual gland, Wharton duct, and lingual
and hypoglossal nerves and is bound superiorly by the
mucosa of the floor of mouth, laterally by the mandible,
inferiorly by the mylohyoid, medially by the genioglossus,
and anteriorly by the mandible.
What are the two divisions of the submandibular
space?
It is subdivided into the sublingual and submaxillary spaces,
which are separated by the mylohyoid. These two spaces
communicate at approximately the second molar.
Define the boundaries of the submaxillary (sub-mylohyoid) space.
It contains the submandibular gland and is bound superiorly
and medially by the mylohyoid muscle, inferiorly and
posteriorly by the digastric muscle, and laterally and
anteriorly by the superficial layer of the deep cervical fascia
and mandible.
Define the boundaries of the infratemporal fossa.
● Located inferior and medial to the zygomatic arch
● Anterior: Posterolateral portion of maxillary sinus
● Lateral: Ramus of the mandible
● Medial: Lateral pterygoid plate
● Superior: Greater wing of the sphenoid bone
● Inferior: Medial pterygoid muscle
● Posterior: Articular tubercle of the temporal bone,
glenoid fossa
Describe the branches of the three segments of
the internal maxillary artery.
● First (lateral) portion: Deep auricular artery, anterior
tympanic artery, middle meningeal artery, inferior
alveolar artery, accessory meningeal artery
● Second (middle) portion: Masseteric artery, pterygoid
branches, anterior and posterior deep temporal arteries,
buccal artery
● Third (medial) portion: Sphenopalatine artery (terminal
branch), descending palatine artery, infraorbital artery,
artery of the vidian canal, anterior, middle, and posterior
superior alveolar artery
Define the boundaries of the pterygopalatine
fossa.
● Located medial to the infratemporal fossa
● Anterior: Posteromedial portion of maxillary sinus
● Lateral: Pterygomaxillary fissure and infratemporal fossa
● Medial: Perpendicular plate of the palatine bone
● Superior: Body of the sphenoid bone
● Inferior: Pterygopalatine canal
● Posterior: Root of the pterygoid plates
Name the foramina communicating with the
pterygopalatine fossa.
● Anterior: Inferior orbital fissure ● Lateral: Pterygomaxillary fissure ● Medial: Sphenopalatine foramen ● Interior: Greater palatine canal ● Posterior: Vidian canal, foramen rotundum
What important structure may be encountered if
the vidian canal is followed posteriorly?
The second genu of the internal carotid artery
Define the boundaries of the temporal fossa.
It is located between the superficial layer of the temporalis
fascia and the periosteum of the squamosal portion of the
temporal bone and is subdivided into the superficial and
deep layer by the temporalis muscle. It contains the internal
maxillary artery and inferior alveolar nerve.
During submandibular gland excision, the marginal mandibular nerve cannot be readily identified. What strategy can be used to decrease the risk of marginal mandibular nerve injury?
The common facial vein can be identified low, ligated, and
divided and then reflected superiorly because the marginal
mandibular nerve rests superficial to the common facial
vein and facial artery in the region of the mandibular notch.
Describe the location and course of the hypoglossal and lingual nerves in the region of the submandibular gland.
It is located deep to the digastric muscle and mylohyoid and
superficial to the hypoglossus muscle. The lingual nerve is
located cephalad to the hypoglossal nerve.
What landmarks can be used for identification of
the accessory nerve during level 2 neck dissection?
Transverse process of C1, anterolateral to the internal
jugular vein, two fingerbreadths below the mastoid tip, or
just as it runs posterior to the sternocleidomastoid 1 to
2 cm above the Erb point
Describe the location of the phrenic nerve and superior sympathetic chain.
It is located anterior to the anterior scalene muscle. The
phrenic nerve runs lateral to the sympathetic chain.
The hypoglossal nerve is “pinned” by what artery as
it descends behind the digastric muscle?
The occipital artery
Describe five methods or landmarks for identifying
the facial nerve during parotidectomy.
The tragal pointer, tympanomastoid suture line, level of the digastric groove (posterior digastric muscle), retrograde
from marginal mandibular nerve at mandibular notch,
anterograde from the vertical segment of the mastoid
During deep-lobe parotidectomy, what arteries
must be divided for en bloc removal?
External carotid artery, superficial temporal artery, internal
maxillary artery
Which cervical rootlets contribute to the ansa
cervicalis?
C1, C2, and C3
Which deep neck spaces involve the entire length
of the neck?
Four: the retropharyngeal, danger, prevertebral, and carotid
spaces
Describe the parasympathetic innervation to the
parotid gland.
Inferior salivatory nucleus → cranial nerve IX (Jacobson
nerve) → lesser superficial petrosal nerve → otic ganglion →
auriculotemporal nerve (V3) → parotid gland
Describe the parasympathetic innervation to the
submandibular gland and sublingual glands.
Superior salivatory nucleus → nervus intermedius → cranial nerve VII → chorda tympani → lingual nerve → submandibular ganglion → submandibular gland
Describe the parasympathetic innervation to the
lacrimal gland.
Superior salivatory nucleus → greater superficial petrosal
nerve → vidian nerve → sphenopalatine ganglion → lacrimal
branch V1 → lacrimal gland
