Physician Assistant PAS 701/2/3 PA Examination Question Pool: Head and Neck - 1430-1700hrs, December 11, 2019

Note: The answer guides is are not "the answer." For the essay examination, please be prepared to answer questions in prose. The guides are not exhaustive. Your answer does not require that all points in the guide are addressed. Plus, you may receive credit for writing about relevant information not mentioned in the guide. Each question spans multiple lectures. Thus, the placement of a question according to a particular lecture is somewhat arbitrary.

Applied Human Structure and Function PAS-703 Head and Neck Examination Preview (3 Questions Currently Known)

  • PA_HeadNeck2019Preview.pdf - Expect that grammatical corrections will be applied to the final version of the examination.
  • As was the case for the previous written examination, if one of the 10 questions does not resonate with you, then you may substitute another question from the question pool. Or, you may write a question of your own. The question must be relevant to the subject and of an academic spirit comparable to the question pool. Please avoid being overly redundant with another answered question.
  • Between the 7 known questions (Cervical Fascia and Ludwig's Angina, Pancoast Tumor and Vertebral Triangle, Thrombosis of Cavernous Sinus) and the opportunity to substitute a single question; you currently know 7 of 10 questions to be on the examination.
  • Please plan on answering all 10 questions, in prose, during the examination time.
  • Notice that each question ends with "Cite an example of clinical relevance." In most cases the clinical relevance is self-evident. Nonetheless, if you have additional comment about clinical relevance; please write a note about it. Especially comment if your laboratory experience has, in any way, inspired your clinical knowledge. Explicitly citing an example of clinical relevance is not essential to answering the question.
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Cervical Fasciae

A 51 year old male presents to the Free Clinic with complaints of neck pain and feeling short of breath.\xA0 He states he had a toothache two weeks ago and had some swelling on his lower left jaw.\xA0 He took some Tylenol with minimal relief.\xA0 Over the last 24 hours, he has had fever and chills, some difficulty swallowing and swelling in his neck.\xA0 On exam, his temperature is 103 F, he is tachycardic, with a blood pressure of 100/60. He appears acutely ill and when asked to lay back he refuses since doing so makes him feel like he can't breath.\xA0 Exam of his mouth shows his tongue to be elevated and posteriorly displaced. He has multiple deep cavities in his teeth.\xA0 His neck has firm edema, is warm and tender to the touch.\xA0 On auscultation you hear a high pitched noise (stridor) in his neck but not in his lungs. An x-ray of his teeth shows an apical abscess on the lower left second molar. Discuss the spaces defined by the cervical fasciae. Include boundaries, contents, relationships, lymphatic drainage, and significance.

Cervical Investing Fascia Attachments and Specialization

  • from posterior cervical spines (nuchal ligament)
  • envelopes trapezius and sternocleidomastoid muscles
  • envelopes strap muscles
  • envelopes parotid gland (parotid fascia) and submandibular gland
  • superior limits - mandible anterior, scalp posterior
  • inferior limits - sternum, clavicle, acromion, vertebra prominens
  • creates a continuous collar (carpet)

Pretracheal Visceral Fascia Attachments and Specialization

  • surrounds the cervical viscera - thyroid gland, trachea, esophagus, recurrent laryngeal nerves
  • posterior: buccopharyngeal fascia (named part of pretracheal visceral fascia)
  • superior limit - thyroid cartilage
  • inferior limit - superior/anterior mediastinum

Prevertebral Fascia Attachments and Specialization

  • surrounds the intrinsic musculature of the cervical vertebral column
  • attached to the spinous processes of the cervical vertebrae
  • partly covers splenius capitis, levator scapula, scalene muscles, longus colli, longus capitus, anterior vertebral bodies
  • superior limit - base of skull near pharyngeal tubercle
  • inferior limit - continuous throughout thorax
  • alar layer of prevertebral fascia - second layer of prevertebral fascia attached to transverse processes, border for "danger space"
  • diverticulum of prevertebral fascia at interscalene triangle forms the axillary sheath
    • space defined by axillary sheath is continuous with space defined by prevertebral fascia
    • anesthesia of brachial plexus could block phrenic nerve - watch out for bilateral effects!

Spaces Defined by Cervical Fascias

  • pretracheal space - defined by the collar of pretracheal fascia
    • from thyroid cartilage to superior mediastinum
  • retropharyngeal space - defined by pretracheal visceral fascia (buccopharyngeal fascia part) and prevertebral fascia
    • extends from the pharyngeal tubercle to the posterior mediastinum (where alar fascia blends with visceral fascia)
    • especially important for considerations of spread infection
    • infections can enter this space through compromise of the buccopharyngeal fascia (the "throat")
  • danger space (prevertebral space) - between alar layer of prevertebral fascia and prevertebral fascia
    • from base of skull (pharyngeal tubercle) and extending inferiorly throughout the thorax

Lymphatic Drainage

  • Submandibular and submental nodes
  • Retropharyngeal nodes
  • Lateral and medial cervical nodes
  • Deep cervical nodes

Significance

  • Spread of infection - lower molars, pharynx, tonsils
  • Dispersion to superior and posterior mediastinum
  • Airway obstruction - Ludwig's angina
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Left Vertebral Triangle and Pancoast Tumor

A seventy two year-old male comes to your office with complaints of hoarseness and postnasal drip. You note the distinct smell of tobacco. He has ptosis of the left eye and the left pupil is smaller than the right. There is fullness over the left supraclavicular region. A Pancoast tumor is highly suspected. Discuss the anatomy of the left vertebral triangle. Include boundaries, contents, relationships, fascial specializations, vasculature, innervation, and lymphatic drainage. (12 pts)

General Comments

  • The vertebral triangle shares a lateral border with the anterior border of the interscalene triangle. This common border is provided by the interscalene muscle. The vertebral triangle and its contents account for the predominant features of the root of the neck.

Boundaries

  • Superior - Transverse Process of C6 (carotid tubercle is key relationship)
  • Inferior - First rib from vertebral body T1 to insertion of anterior scalene (first part subclavian artery) -
  • Anterior - Prevertebral Fascia
  • Posterior - Intrinsic posterior cervical muscles at posterior border of transverse process C6 - T1
  • Medial - Vertebral bodies of C6 - T1 and longus colli
  • Lateral - Anterior Scalene Muscle

Contents, Relationships, and Fascial Specializations

  • Intrinsic
    • Vertebral artery (transverse process of C6) - transverse foramen, posterior to common carotid at carotid tubercle, vertebral ganglion
    • Vertebral vein (transverse process of C7) - transverse foramen
    • Subclavian artery - parts of, interscalene triangle, subclavian vein is anterior to anterior scalene
    • Thyrocervical trunk and branches (4)
      • inferior thyroid passes posterior to carotid sheath, ascending cervical on anterior scalene medial to phrenic nerve, transverse cervical and suprascapular arteries cross anterior scalene, phrenic nerve, and fascia
    • Costocervical trunk and branches (2) - posterior margin of subclavian, arguably not in vertebral triangle but the ascending cervical and supreme thoracic branches enter vertebral triangle
    • Dorsal scapular artery (inconsistent) - three possible cites of origin including thyrocervical trunk
    • Internal thoracic artery (definitional) - inferior margin of subclavian artery, lateral to vertebral artery
    • Phrenic nerve - crosses anterior scalene to enter vertebral triangle near first rib
    • Stellate and vertebral sympathetic trunk ganglia - anterior surface of the neck of the first rib
    • Ansa subclavia - communication between stellate and vertebral/middle cervical sympathetic trunk ganglia
    • Thoracic duct - enters between brachiocephalic and internal jugular vein, ascends posterior to subclavian artery
    • Roots of the brachial plexus
  • Extrinsic
    • Prevertebral fascia - superficial to phrenic nerve
    • Carotid sheath and contents -
    • Cervical sympathetic trunk -
    • Recurrent laryngeal nerve -
    • Roots C6 - T1 brachial plexus (arguably intrinsic) -

Innervation

  • Cervical and brachial plexuses -
  • Sympathetic trunk and derivatives -

Lymphatic drainage

  • Deep cervical nodes -
  • Thoracic duct

Compression of the common carotid artery

  • Carotid tubercle -

Significance

  • A surgical nightmare of critical structures
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Tempormandular Joint and Infratemporal Fossa

A 27 year-old male medical student presents with complaints of left sided headache. He has been studying for an upcoming neuroanatomy exam and is now convinced that he has a \x93brain tumor.\x94 He states it is \x93worse in the morning\x94 and thinks it might be affecting his hearing because he has noted some pain in his left ear. On exam, the patient has some difficulty opening his mouth and it appears that his mandible deviates to the left side. His left external ear canal and tympanic membrane are normal in appearance and he has no hearing deficits on gross testing. When you palpate anterior to the tragus of the left ear it is tender and there is a \x93clicking\x94 appreciated with jaw opening. Review the anatomy of the temporomandibular joint and infratemporal fossa. Include bones, boundaries, contents, bony communications, ligaments, muscles, movements and limitations of movement, vasculature and venous communications, innervation and functional components, relationships to surrounding structures, lymphatic drainage, and significance. (12 pts)

Bones of the Temporomandibular Joint

  • Postglenoid tubercle - posterior margin of mandibular fossa of the temporal bone zygomatic process
  • Mandibular fossa - receives the head of the mandible
  • Articular eminence of the zygomatic process of the temporal bone - anterior margin of the mandibular fossa
  • Coronoid process of the mandible - insertion for temporalis muscle
  • Neck of the mandible - insertion for the lateral pterygoid muscle (inferior)
  • Lingula - attachment of the sphenomandibular ligament
  • Angle of the mandible lateral side - insertion for the masseter muscle
  • Angle of the mandible medial side - insertion for the medial pterygoid
  • Temporal fossa and superior/inferior temporal lines - origin of the temporalis muscle and fascia
  • Lateral and medial surfaces of the the lateral pterygoid plate - origins of the lateral and medial pterygoid muscles
  • Infratemporal crest - origin of the superior head of the lateral pterygoid
  • Zygomatic arch - origin of the masseter muscle

Articulations of the Temporomandibular Joint

  • Mandibular fossa
  • Articular disk
  • Condyle of the mandible
  • Superior and inferior synovial joint cavities
  • Posterior, lateral, and anterior joint capsule and ligaments

Muscles and movements

  • Masseter - elevation and ipsilateral deviation
  • Medial pterygoid - elevation and contralateral deviation
  • Superior head lateral pterygoid - depression, protraction, and contralateral deviation
  • Inferior head lateral pterygoid - elevation, protraction, and contralateral deviation
  • Posterior temporalis - elevation, retraction, and ipsilateral deviation
  • Anterior temporatlis - elevation
  • Infrahyoid muscles - depression of the mandible

Innervation

  • Muscles of mastication - mandibular division of trigeminal
  • Strap muscles - ansa cervicalis
  • Nerve to mylohyoid, thyrohyoid, and geniohyoid
  • Hilton's law for the joint capsule plus the auriculotemporal nerve

Relationships of the Temporomandibular Joint

  • Medial - petrotympanic fissure and chorda tympani nerve, styloid process and infratemporal fossa
  • Lateral - parotid region, parotid gland, facial nerve,
  • Superior - mandibular fossa, temporal fossa
  • Inferior - lingula, digastric triangle, maxillary artery
  • Anterior - articular tubercle
  • Posterior - external auditory meatus, auriculotemporal nerve, parasympathetic communicating branch,

Boundaries of the Infratemporal Fossa

  • anterior - posterior aspect of maxilla
  • posterior - styloid process
  • superior - infratemporal crest
  • inferior - body of mandible
  • medial - pterygoid plate (pterygo maxillary fissure)
  • lateral - ramus of mandible

Bony communications

  • Foramen ovale - middle cranial fossa to infratemporal fossa, mandibular nerve (GSA, SVE) and lesser superficial nerve (Preganglionic GVE)
  • Foramen spinosum - middle cranial fossa to infratemporal fossa, middle meningeal artery
  • Petrotympanic fissure - middle ear to infratemporal fossa, chorda tympani nerve (SVA, preganglionic GVE)
  • Inferior orbital fissure - maxillary artery becomes infraorbital artery
  • Pterygomaxillary fissure - terminal branches of maxillary artery, posterior superior alveolar nerve (GSA and postganglionic GVE)
  • Mandibular foramen - inferior alveolar nerve (GSA) and artery

Contents - ligaments, muscles, movements and limitations of movement

  • Temporomandibular joint
  • Sphenomandibular ligament
  • Pterygomandibular raphe
  • Lateral and medial pterygoid muscles - protraction and elevation plus secondary actions

Vasculature and venous communications

  • Maxillary artery and branches
  • Pterygoid venous plexus - communicates with orbit and face, with retromandibular vein to neck and face, foramen ovale to cavernous sinus

Innervation and functional components

  • Mandibular branch of trigeminal nerve - GSA SVE
  • Chorda tympani - SVA GVE
  • Lesser superficial petrosal nerve - GVE

Lymphatic drainage and significance

  • Pathways to deep and superfical cervical nodes
  • Muscles of mastication
  • Spread of infection to intracranial locations
  • Gateway to the pterygopalatine fossa and route for injection to treat trigeminal neuralgia

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Cavernous Sinus

A 38 year-old male presents to the E.D. with a swollen left eye. He denies any trauma to the eye. He does report, initially, having a headache \x93on the top of my head.\x94 He now has a generalized headache, fevers, pain behind his eye, and if you open his eyelid he reports double vision. On exam, the patient appears ill with obvious ptosis, proptosis, and inability to track with his left eye during extra-ocular muscle testing. He has hyperesthesia on the skin of his left face, from the forehead to just above the mandible. His fundoscopic exam displays papilledema. Discuss the anatomy of the cavernous sinus. Include boundaries, contents, and relationships. What symptoms are caused by damage to the structures and cranial nerve functional components within the cavernous sinus? (12 pts)

General Comments

  • The cavernous is a venous blood sinus (not an air sinus) created by divergent layers of endosteal and meningeal dura. It is located in the middle cranial fossa adjacent to the sella turcica. Immediately medial to the thin lateral border of the sella turcica is the sphenoid air sinus. This relationship puts the cavernous sinus at risk during transsphenoidal surgery of the hypophysis. Five of the 12 cranial nerves have components at risk during pathology of the cavernous sinus.

Bones

  • Sella turcica -
  • Greater wing of the sphenoid bone -
  • Lesser wind of the sphenoid bone -
  • Apex of the petrous temporal bone
  • Anterior and posterior clinoid processes -

Boundaries and external relationships

  • Superior -
  • Inferior -
  • Anterior -
  • Posterior -
  • Medial -
  • Lateral -

Contents, internal relationships, functional components, and expected clinical symptoms

  • Internal carotid artery -
  • Internal carotid plexus -
  • Sympathetic root of the ciliary ganglion -
  • Deep petrosal nerve -
  • Greater superficial petrosal nerve -
  • Nerve of the pterygoid canal (Vidian nerve) -
  • Oculomotor nerve (and branches) -
  • Trochlear nerve -
  • Ophthalmic nerve (V1) and branches -
  • Maxillary nerve (V2) -
  • Abducens nerve -
  • Inferior hypophyseal artery

Vascularization

  • Hypophyseal arteries -
  • Ophthalmic vein -
  • Sphenoparietal sinus -
  • Superior petrosal sinus -
  • Inferior petrosal sinus -
  • Emissary vein to pterygoid venous plexus -
  • Intercavernous sinus sinus -

Innervation

  • Meningeal branches of maxillary and mandibular nerves -

Routes of Infection

  • Face and Orbit -
  • Scalp -
  • Infratemporal fossa -
  • Ischiorectal fossa and internel vertebral venous plexus -
  • Base of skull and external vertebral venous plexus -
  • Intercavernous sinus -
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Pterygopalatine Fossa and Maxillary Nerve Distribution

Dr. Bollard explained that patients with trigeminal neuralgia need to decide for themselves what is worse; the pain of neuralgia or the numbness that results from nerve block. A treatment for trigeminal neuralgia is to inject nerve blocking agents into the pterygopalatine fossa. Discuss the distribution of the maxillary division of the trigeminal nerve. Include foramina, spaces, and functional components. \xA0 Predict the neural deficits that may result from lesions at different locations along the course of the zygomaticotemporal nerve. (12 pts)

General Comment

  • Trigeminal nerve begins in posterior cranial fossa, crosses superior petrosal ridge inferior to superior petrosal sinus, trigeminal ganglion at trigeminal cave and anterior medial slope of petrous temporal bone
  • Maxillary nerve is a branch from trigeminal ganglion, passes anterior within floor of the cavernous sinus along lateral inferior margin of sella turcica, leaves middle cranial fossa by foramen rotundum
  • The maxillary nerve and its branches pass through the pterygopalatine fossa. These branches disperse to the regions of the face, nasal cavity, nasopharynx, maxillary sinus, orbit, and oral cavity.

The Pterygopalatine Fossa

  • Maxillary nerve and branches (GSA)
  • Pterygopalatine ganglion - site of postganglionic parasympathetic cell bodies (GVE)
  • Nerve of the pterygoid canal - conveys GVA, preganglionic parasympathetic GVE, and SVA from the facial nerve and postganglionic GVE sympathetics from the internal carotid plexus
    • Greater superficial petrosal nerve combines with deep petrosal nerve within the cavernous sinus and near the anterior lip of the lacerate foramen to form nerve of the pterygoid canal
  • Arteries/veins named for the foramina that they pass through

Boundaries of the Pterygopalatine Fossa

  • Anterior
    • inferior orbital fissure - between lesser wing of sphenoid and maxilla
      • Maxillary nerve continues as infraorbital nerve
      • Zygomatic nerve (GSA, postganglionic GVE)
  • Posterior
    • Greater wing of the sphenoid
    • Foramen rotundum: PPF to MCF, greater wing of sphenoid
      • Maxillary nerve (GSA)
      • Artery of foramen rotundum (the maxillary nerve)
    • Body of the sphenoid bone
      • pterygoid canal: PPF to MCF (lacerate foramen)
    • Anterior wall of the sphenoid sinus - pterygoid canal along floor
    • Pterygoid canal - floor of sphenoid sinus
    • Palatovaginal canal - vaginal process of sphenoid bone and sphenoid process of palatine bone
  • Superior: body of sphenoid bone
    • Sphenoid sinus
    • Sphenoethmoidal recess
  • Inferior
    • inferior and posterior wall - palatovaginal canal: PPF to nasopharynx, vaginal process of
    • Inferior and posterior - lesser palatine canal: PPF to soft palate
    • Inferior and anterior - greater palatine canal: PPF to hard palate
    • The greater and lesser palatine canals may share common superior opening, palatine bone and maxilla
  • Medial
    • sphenopalatine foramen - perpendicular plate palatine bone and medial pterygoid plate
    • perpendicular plate of palatine bone
    • medial pterygoid plate
  • Lateral
    • pterygomaxillary fissure - posterior aspect of maxilla and anterior border of lateral pterygoid plate

Foramina and Functional Components

  • Foramen rotundum
    • maxillary nerve
      • GSA - cell bodies in trigeminal ganglion, distribute to face, orbit, nasopharynx, oral cavity, nasal cavity, nasopharynx, sphenoid and maxillary air sinuses
  • Pterygoid canal
    • Vidian nerve (nerve of the pterygoid canal)
      • Formed within lacerate foramen by union of the greater superficial petrosal nerve and the deep petrosal nerve
      • GVE - Postganglionic sympathetic from internal carotid plexus (cell bodies in superior cervical sympathetic trunk ganglion)
      • GVE - Preganglionic parasympathetic cell bodies in lacrimal nucleus and native to greater superficial petrosal nerve (CNVII)
      • SVA - Taste to the hard and soft palate cell bodies in geniculate ganglion and native to greater superficial petrosal nerve (CNVII)
      • GVA - Touch to the soft palate, cell bodies in geniculate ganglion and native to greater superficial petrosal nerve (CNVII)
  • Inferior orbital fissure
    • Infraorbital nerve GSA - Touch to maxillary sinus and face, cell bodies in trigeminal ganglion
    • Zygomatic nerve GSA GVE - Touch to face, motor to mucosa, postganglionic parasympathetic cell bodies in the pterygopalatine ganglion
      • Zygomatic nerve to zygomaticotemporal nerve to lacrimal nerve to lacrimal gland
  • Pterygomaxillary fissure
    • Posterior superior alveolar nerve GSA GVE - enters posterior wall of maxillary sinus within the infratemporal fossa
  • Sphenopalatine foramen
    • Lateral posterior nasal nerves (superior middle and inferior) GSA GVE - distributes to turbinates of lateral posterior nasal wall
    • Nasopalatine nerve GSA GVE SVA - distributes to nasal septum and anterior hard palate
  • Greater palatine canal
    • Greater palatine nerve GSA GVE SVA - distributes to the hard palate
  • Lesser palatine canal
    • Lesser palatine nerve GSA GVE SVA GVA - distributes to the soft palate
  • Palatovaginal canal (pharyngeal canal)
    • Pharyngeal nerve GSA GVE - distributes to the the nasopharynx

Zygomaticotemporal Nerve

  • Lesion proximal to to the branching of the GVE communicating branch disrupts lacrimation and causes paraesthesia to the anterior temporal region of the face
  • Lesion distal to the branching of the GVE communicating branch does not disrupt tearing, but does cause paraesthesia to the anterior temporal region of the face
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Larynx

A 57-year-old male underwent a left hemithyroidectomy for a benign adenoma.\xA0 The patient complains of persistent hoarseness. He also notes occasional coughing, a sense of shortness of breath, and vocal fatigue. Operative damage to the left recurrent laryngeal nerve is indicated. Review the anatomy of the larynx. Include bones, cartilages, spaces, boundaries, ligaments, muscles, movements and limitations of movement, vasculature, innervation and functional components, relationships to surrounding structures, lymphatic drainage, and function. (12 pts)

General Comment

  • The larynx functions in breathing, swallowing, and phonation
  • Alimentary canal pathway crosses airway pathway

Relationships

  • Superior - oropharynx, nasopharynx, oral cavity, epiglottis
  • Inferior - cricopharyngeus muscle (upper esophageal sphincter), esophagus
  • Anterior - pretracheal fascia, pretracheal space, strap musculature, isthmus of thyroid
  • Posterior - pharynx, vertebral bodies, buccopharyngeal fascia, prevertebral space, carotid sheath and contents, inferior thyroid artery
  • Lateral (left/right) - piriform recesses, hypopharynx, vagal nerve branches, thyroid gland,

Bones and Cartilages

  • Comment - Rigidity of cartilage framework allows for airway patency and muscular attachments
  • Hyoid bone
    • Free floating and from the 2nd and 3rd branchial arches
    • Attachment for the supra- and infrahyoid musculature, tongue musculature
    • Lesser and greater cornu
  • Thyroid cartilage
    • Large shield-like cartilage making up anterior and lateral walls larynx
    • Laryngeal prominence
    • Thyrohyoid membrane
    • Synovial articulation with cricoid cartilage, cricothyroid membrane (anteriorly)
    • Anterior site of attachment for true and false vocal cords
    • Prominence - posterior and superior
    • superior cornu and inferior cornu
  • Cricoid cartilage
    • Complete cartilaginous ring shaped like a signet ring with widest part facing posterior, 2-3 cm in height posteriorly
    • Cricothyroid joint - synovial
    • Continuous with trachea
  • Epiglottis
    • Anterior and superior of larynx
    • Hyoepiglottic ligament and thyroepiglottic ligaments
    • Vallecula on either side of median glossoepiglottic fold and lateral glossoepiglottic folds
    • Elevates during swallowing
  • Arytenoid cartilage
    • Articulates with posterior/superior margin of cricoid cartilage
    • Vocal processes - vocal ligament, vocalis muscle, and thyroarytenoid muscle
    • Muscular process - lateral and posterior cricothyroid muscles, interarytenoid muscle
  • Corniculate cartilage
    • Small cartilages resting on the superior aspect of the arytenoid cartilages
    • Rudimentary in humans, with possible role in esophageal opening in animals
  • Cuneiform cartilage
    • Small isolated cartilage within the aryepiglottic folds
    • No clear function
  • Elastic membranes
    • Quadrangular membrane - superior is aryepiglottic fold and inferior is false vocal fold
    • Conus elasticus - thyroid to cricoid cartilages, superior margin is the true vocal fold

Laryngeal musculature

  • Intrinsic muscles
    • Cricothyroid muscle - acts at cricothyroid joint, rocks thyroid cartilage anterior, external laryngeal nerve, tenses true vocal cord, raises pitch
    • Thyroarytenoid muscle - origin at inner surface of thyroid cartilage and insertion at vocal process of arytenoid cartilage, recurrent laryngeal nerve, includes vocalis muscle at superior edge, adducts, shortens, and tenses vocal folds
    • Posterior cricoarytenoid muscle - posterior cricoid cartilage to muscular process of arytenoid cartilage, abducts true folds
    • Lateral cricoarytenoid muscle - lateral cricoid cartilage to muscular process of arytenoid cartilage, adducts vocal folds
    • Interarytenoid muscle - connects arytenoid cartilages, adducts vocal folds
    • Cricoarytenoid joint - adduction/abduction, rocking
    • Cricothyroid joint - rocking (pivot) of thyroid cartilage on the cricoid cartilage, lengthens and tenses true vocal cord
  • Extrinsic muscles
    • infrahyoid muscles, depressors of larynx, ansa cervicalis, omohyoid, sternohyoid, sternothyroid
    • Suprahyoid muscles, elevators of larynx, thyrohyoid (cervical plexus), stylohyoid (VII SVE), digastric (V, VII, SVE), mylohyoid (V SVE), stylopharyngeus (IX SVE), palatopharyngeus (X SVE), salpingopharyngeus (X SVE)
    • Pharyngeal musculature
      • Superior constrictor - hamulus of medial pterygoid, pterygomandibular raphe, mylohyoid line, and the pharyngeal tubercle, pharyngeal raphe
      • Middle constrictor- greater and lesser cornu of hyoid bone, stylohyoid ligament, pharyngeal raphe
      • inferior constrictor - lateral surface thyroid cartilage, cricoid cartilage, pharyngeal raphe
      • cricopharyngeus - inferior portion of inferior constrictor, upper esophageal sphincter

Mucosal anatomy

  • True vocal fold - superior free edge of conus elasticus
  • False vocal fold - inferior free edge of quadrangular membrane
  • Ventricle: diverticulum between true and false folds
  • Saccule: anterior located extension of ventricle having glandular tissue
  • Epiglottis, aryepiglottic folds
  • Piriform sinuses of laryngopharynx funnel toward esophagus

Voice Production

  • Power source: exhalation
  • Sound source: Vibration of the true vocal fold, subglottic pressure exceeds glottic closing pressure
  • Abduction/adduction and tension of vocal folds
  • Post-production modifier, supraglottic space, oropharynx, nasopharynx, air sinuses
  • Cycle creates fundamental vibration frequency of 80-200 Hz in men, 150-350 Hz in women

Swallowing

  • Closure of true and false vocal folds
  • Larynx raised by extrinsic muscles and epiglottis folds over the aditus (aryepiglottic muscle assists)
  • Bolus passes from vallecula into piriform recess by crossing the lateral glossoepiglottic folds
  • Relaxation of cricopharyngeus allows passage into the esophagus

Innervation

  • Recurrent laryngeal nerve
    • Vagus nerve (CN X) for larynx proper
    • Recurrent laryngeal nerve provides SVE to intrinsic muscles except for cricothyroideus (external branch superior laryngeal nerve), GVA to mucosa inferior to ventricle (infraglottic)
    • Right recurrent laryngeal nerve recurs at subclavian artery, ascends posterior to subclavian artery in tracheoesophageal groove
    • Left recurrent laryngeal nerve recurs at aortic arch, ascends medial to arch in the tracheoesophageal groove.
    • Right and left recurrent laryngeal nerves ascend posterior to the thyroid gland and to the cricothyroid joint to become the inferior laryngeal nerves
  • Internal branch of superior laryngeal nerve (GVE GVA)
    • Superior laryngeal nerve branches for the vagus nerve immediately inferior to the nodose ganglion
    • Internal laryngeal nerve passes through thyrohyoid membrane superior to superior laryngeal artery to provide GVA to the vestibule
    • Mediates afferent limb of cough reflex (GVA)
  • External branch of superior laryngeal nerve (SVE)
    • SVE to cricothyroideus muscle and possibly cricopharyngeus muscle (upper esophageal sphincter), raises pitch

Vascular Supply

  • Paired branches from the external carotid system
  • Superior laryngeal artery arises from the superior thyroid artery, passes through thyrohyoid membrane inferior to the internal branch of the superior laryngeal nerve
    • runs across floor of piriform sinus, supplies mucosa and musculature of larynx mostly superior to false vocal fold
  • Inferior laryngeal artery from inferior thyroid artery
    • runs deep to inferior pharyngeal constrictor along with the recurrent laryngeal nerve, supplies mucosa and musculature of larynx mostly inferior to true vocal fold
  • Superior and inferior thyroid arteries anastomose in the vicinity of the ventricle.
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Facial Nerve

On the first day of your fourth year neurology rotation as a medical student, you are asked to see two patients complaining of right facial droop.\xA0 The first patient is found to have a tumor on the cranial floor at the entrance to the internal acoustic meatus.\xA0 The second patient has a tumor at the stylomastoid foramen. Discuss the anatomy, functional components, and distribution of the facial nerve. \xA0 Compare the deficits resulting from a lesion of the facial nerve at the internal auditory meatus to the deficits resulting from a lesion of the facial nerve at the stylomastoid foramen. (12 pts)

Anatomy

  • Posterior cranial fossa
  • Internal auditory meatus
  • Horizontal part
    • Geniculate ganglion and greater superficial petrosal nerve
  • Descending part
    • Nerve to stapedius
    • Chorda tympani
  • Stylomastoid foramen
  • Posterior auricular branch and main trunk
  • Nerves to stylohyoid and posterior belly digastric
  • Motor nerves to muscles of facial expression including the buccinator
    1. Temporal branch - orbicularis oculi
    2. Zygomatic branch - orbicularis oculi
    3. Buccal branch - buccinator
    4. Mandibular branch - orbicularis oris
    5. Cervical branch - platysma

Distribution and Nerve Injury

  1. Stylomastoid Foramen (GSA SVE)
    • Motor and sensory to external ear by posterior auricular nerve - anesthesia within external auditory meatus and posterior pina, limited ear movement
    • Stylohyoid muscle and posterior belly digastric muscle - difficulty with swallowing, depressing the mandible, and raising the larynx
    • Motor to muscles of facial expression by main nerve trunk - facial paralysis, difficulty positioning food in occlusion plane
    • Postganglionic parasympathetic to parotid are spared
  2. Distal to nerve to stapedius and proximal to chorda tympani (SVA, GVE)
    • Taste to anterior 2/3 of tongue
    • Preganglionic parasympathetic to submandibular gland - dry mouth
  3. Distal to greater superficial petrosal nerve and proximal to stapedial nerve (SVE)
    • Stapedius muscle - hyperacusis
  4. Proximal to greater superficial petrosal nerve (GVA, SVA, GVE)
    • Touch, temperature, pain to posterior parts of soft palate
    • Taste to hard and soft palate (excluding immediately posterior to the upper incisors)
    • Mucosal secretion from hard palate, soft palate, nasal cavity, and maxillary sinus - dry mouth and dry mucosa
    • Lacrimation - dry eye
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Orbit

A 12 year old girl is playing Little League baseball when she is struck in the right eye by a batted ball. In the emergency department the soft tissues around her right eye are swollen to the extent that she cannot open her eye.\xA0 Her globe is not ruptured but is displaced inferior, and a CT scan reveals a fractured floor and medial wall of her right orbit. The inferior orbital fissure and its structures are compromised. Review the anatomy of the orbit. Include bones, contents, relationships, fascial specializations, muscles, vasculature, innervation, and lymphatic drainage. Discuss the deficits resulting from injury to the structures passing through the inferior orbital fissure. (12 pts)

Bones and Foramina

  • Orbital Walls
    • Superior - orbital plate of frontal bone
    • Inferior - maxilla
    • lateral - zygoma
    • Medial - lacrimal bone, ethmoid bone, palatine bone
    • Posterior - greater wing of sphenoid bone, body of sphenoid bone,
  • Foramina
    • Optic foramen - optic nerve, ophthalmic artery, central artery
    • Superior orbital fissure - III, IV, V1, VI, ophthalmic vein
    • Inferior orbital fissure - V2, infraorbital artery and vein, zygomatic nerve and branches
    • Infraorbital groove, canal, and foramen
    • Anterior and posterior ethmoidal foramina
    • Foramina for the zygomaticotemporal and zygomaticofacial nerves
    • Canal for the nasolacrimal duct

Contents

  • Periorbita
  • Bulbar fat
  • CN2,3,4,5 (V1 and V2),6,7
  • Sympathetic root of ciliary ganglion
  • Extraocular muscles
  • Globe - chambers, lens, ciliary body, dilator, sphincter
  • Ophthalmic artery and branches
  • Opthalmic vein and branches
  • Ciliary ganglion
  • Annulus tendineus
  • Lacrimal gland

Relationships

  • Structures passing through annulus tendineus
  • Ciliary ganglion
  • Trochlea

Fascial specializations

  • Annulus tendineus
  • Periorbita
  • Bulbar fat
  • Trochlear
  • Orbital septum, palpebral ligaments, tarsal plates
  • Conjunctiva

Muscles and movements

  • Rectus muscles
  • Rotation by the obliques
  • Levator palpebrae superioris and superior tarsal muscle
  • Orbicularis oculi

Vascularization

  • Ophthalmic artery and branches
    • Lacrimal artery
    • Supraorbital artery
    • Supratrochlear artery
    • Infratrochlear artery
    • Anterior ethmoidal artery and clinical significance
    • Posterior ethmoidal artery
  • Ophthalmic vein and branches
    • Clinical significance of facial and orbital venous drainages
    • Clinical significance of inferior ophthalmic vein and pterygoid venous plexus

Innervation

  • Optic nerve
  • Superior division oculomotor nerve
  • Inferior division oculomotor nerve
  • Motor root of ciliary ganglion
  • Sympathetic root of ciliary ganglion
  • Nasociliary nerve
  • Sensory root of ciliary ganglion
  • Long and short ciliary nerves
  • Anterior and posterior ethmoidal nerves
  • Infratrochlear nerve
  • Lacrimal nerve and non-native fibers
  • Frontal nerve and branches
  • Trochlear nerve
  • Abducens nerve

Lymphatic Drainage

  • Lateral lids and conjunctiva - parotid nodes
  • Medial lids and conjunctiva - submandibular nodes
  • Orbit proper - mostly unidentified (Gray's)

Injury to structures passing through the inferior orbital fissure

  • Infraorbital nerve - paresthesia of face inferior to the orbit extending to angle of nose and including upper lip
  • Infraorbital artery and vein - exophthalmia
  • Zygomatic nerve and branches
    • Zygomaticofacial nerve - paresthesia of face overlying the zygoma
    • Zygomaticotemporal nerve - paresthesia of face posterior to zygoma and the anterior temporal fossa
      • Postganglionic parasympathetic fibers from pterygopalatine ganglion - reduced lacrimation and dry eye
  • Entrapment of inferior rectus muscle - depressed globe

Additional Clinical Notes

  • Pulsating exophthalmos - Arteriovenous shunt within cavernous sinus
  • Inferior root CN3 and ciliary ganglion
  • Abducens and cavernous sinus infection
  • Sympathetic root of ciliary ganglion and ptosis
  • Horner's syndrome
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Horner's Syndrome - Sympathetic Nervous System for the Head and Neck

Discuss the anatomy of the sympathetic nervous system for the head and neck. Include preganglionic and postganglionic cell body locations, anatomical pathways and distributions, and significance. Include an account of Horner's syndrome (sympathetic denervation of the head). (12 pts)

General Comments

  • The sympathetic innervation to the head modulates vascular tone, viscous saliva secretion, sudomotor activity, and pupil dilation. The sympathetic innervation to the neck controls vascular tone and sudomotor activity. The sumpathetic innervation of the thorax and upper limb is derived from cervical sympathetic trunk ganglia. Notably, the brachial plexus receives gray rami from the stellate and middle cervical sympathetic trunk ganglia. These same ganglia provide cardiac nerves the to the mediastinum. The internal and external carotid plexuses of sympathetic fibers are derived from the superior cervical sympathetic ganglion. The vertebral arterial plexus is derived from the vertebral ganglion.

Preganglionic cell bodies

  • Intermediolateral cell column of spinal cord levels T1-T4

Postganglionic cell bodies

  • For the head - superior cervical sympathetic trunk ganglion
    • postganglionic fibers follow the internal and external carotid arterial distribution
  • For the neck, upper limb, and thorax - stellate, vertebral, and middle cervical sympathetic trunk ganglia
    • postganglionic fibers follow cardiac nerves to the thorax, brachial plexus to the upper limb, and cervical arteries

Anatomical pathways

  • Stellate ganglion - fused first thoracic and lower cervical sympathetic trunk ganglia
    • located at anterior surface of the neck of the first rib
    • site of postganglionic cell bodies that supply the brachial and cardiac plexuses
  • Vertebral ganglion
    • located near the inferior margin of the transverse foramen of the C6 vertebra
    • site of postganglionic cell bodies for the vertebral arterial plexus
  • Middle cervical sympathetic trunk ganglion
    • located near the C4 transverse process within the prevertebral space (danger area) immedately anterior longus colli
    • site of postganglionic cell bodies that supply the brachial and cardiac plexuses
  • Superior cervical sympathetic trunk ganglion
    • locate near the transverse processes of the atlas and axis at the base of the skull immediately inferior the the carotid canal
    • elaborates internal and external carotid nerves that, in turn, elaborate the internal and external carotid arterial plexuses of sympathetic fibers
    • site of postganlionic cell bodies that supply the head
  • Cervical sympathetic trunk
    • begins at stellate ganglion of the anterior surface of the neck of the first rib
    • ascends within the prevertebral space immediately anterior the longus colli and posterior to the carotid sheath and contents
    • superior cervical sympathetic trunk ganglion is immediately anterior to longus capitus
  • Ansa subclavia
    • parallel pathway to the cervical sympathetic trunk that passes anterior to the subclavian artery
    • connects the stellate ganglion to either the vertebral or middle cervical sympathetic trunk ganglia or both
    • ascends anterior surface of subclavian artery lateral to the vertebral artery and medial to the internal thoracic artery

Sympathetic Roots of the Parasympathetic Ganglia

  • Ciliary ganglion - sympathetic root of the ciliary ganglion derived from the internal carotid plexus within the cavernous sinus
    • pupillary dilator, ciliary muscle (accommodation), and conjuctiva
  • Pterygopalatine ganglion - deep petrosal nerve derived from the internal carotid plexus within the cavernous sinus
    • vasculature to the mucosa of the maxillary sinus, nasal cavity, oral cavity, and nasopharynx
    • vasculature of the lacrimal gland
  • Otic ganglion - sympathetic root derived from middle meningeal plexus by way of the external carotid plexus
    • vasculature of the parotid region
  • Submandibular ganglion - sympathetic root from the facial arterial plexus by way of the external carotid plexus
    • directly activates secretion of viscous saliva from the submandibular gland in response to irritation
    • vasculature in the regions supplied by the lingual nerve - floor of mouth and anterior two-thirds of the tongue

Horner's Syndrome - Sympathetic Denervation of the Head

  • Constricted pupil - loss of internal carotid plexus and, thus, sympathetic root of the ciliary ganglion
    • parasympathetic control of pupillary constrictor is unopposed
  • Mild ptosis - loss of innervation to the superior tarsal muscle
  • Conjunctival injection (red eye) - loss of vascular tone within the conjunctiva
  • Flushing of the skin of the face - loss of vascular tone
  • Nasal congestion - loss of vascular to the erectile tissues of the nasal cavity
  • Runny nose - loss of vascular tone leads to increased fluid stores
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Oral Cavity and the Anatomy of the tongue

Review the anatomy of the tongue. Include bones, relationships, muscles, vasculature, innervation, and lymphatic drainage.

Innervation

  • Motor by hypoglossal nerve - GSE
  • Anterior 2/3 taste by chorda tympani of facial - SVA
  • Anterior 2/3 touch, temp, pain by lingual - GSA
  • Posterior 1/3 taste by glossopharyngeal - SVA
  • Posterior 1/3 touch, temp, pain by glossopharyngeal - GVA
  • Extreme posterior and epiglottis taste by vagus - SVA
  • Anterior 2/3 secretomotor to mucosa by chorda tympani and submandibular ganglion - parasympathetic GVE
  • Posterior 1/3 secretomotor to mucosa by chorda tympani/submandibular or vagus/glossopharyngeal and unamed ganglia (accept nearly any account for this or omission) - GVE

Bones

  • Syloid process - styloglossus
  • Hyoid bone - hyoglossus

Vasculature (Regional)

  • Lingual artery - branch of external carotid enters oral cavity by passing medial to hyglossus.
  • Fascial artery - inferior labial branch
  • Ascending pharyngeal artery
  • Veins
  • Sublinqual administration of drugs

Muscles

  • Intrinsic - longitudinal and circular
  • Extrinsic - hyoglossus, styloglossus, genioglossus, palatoglossus (vagal innervation)

Relationships

  • Floor of mouth
  • Hard and soft palate (swallowing)
  • Sublinqual gland
  • Submandibular duct
  • Neurovasculature

Lymphatic drainage

  • Submandibular nodes
  • Cervical spaces and carotid sheath

Referred Pain

  • Facial nerve by way of posterior auricular nerve - Ramsy Hunt
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Anatomy of Hearing, Balance, and the Temporal Bone

Review the anatomy of the Hearing. Include bones, relationships, muscles, vasculature, and innervation.

Temporal bone

  • Internal auditory meatus
  • Hiatus of the canal for the greater superficial petrosal nerve
  • Semicircular canals
  • Cochlea
  • Middle ear
  • Round window
  • Oval window
  • Facial canal
  • Stylomastoid foramen

Transduction

  • Pinna
  • External auditory meatus
  • Tympanic membrane
  • Middle ear
  • Ossicles
  • Oval window
  • Round window

Muscles

  • Tensor tympani
  • Stapedius

Vasculature

  • Deep auricular artery
  • More
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Paranasal Sinuses

Dr. Bollard informed us that nasal sinus infections are over-diagnosed. Review the anatomy of the paranasal sinuses. Provide an account for drainages and head positioning to facilitate drainage.

Frontal

  • Opens inferior to middle concha into ethmoid infidibulum or frontal recess (variable)

Maxillary

  • located in the Maxilla, drains high on its medial wall, usually in the infidibulum

Ethmoid air cells

  • Air cells vary in number from 3 to 18, 3 groups: anterior- (open in middle meatus), middle, (middle meatus on the surface of ethmoid bulla), posterior (above superior concha).

Sphenoid

  • Inside sphenoid bone) through anterior wall via sphenoid ethmoidal recess.
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Pterion and Epidural Hematoma

A weekend warrior, not wearing a batter’s helmet, is hit on the side of the head by a wildpitch. Initially, she is “knocked out.” She regains consciousness. Then, thirty minutes later she, once again, loses consciousness. Things do not end well. Discuss the anatomy of the pterion and epidural hematoma.

Pterion

  • Frontal bone
  • Parietal bone
  • Temporal bone (squamous)
  • Sphenoid bone (greater wing)

Dura mater

  • Endosteal layer
  • Meningeal layer
  • Tentorium cerebelli
  • Tentorial incisor and brainstem

Vasculature

  • Middle meningeal artery
  • Trephine
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Pharynx

The interplay between the pharynx and larynx during swallowing is critical to not aspirating. Stroke victims may need to relearn how to swallow. Review the anatomy of the nasopharynx, oropharynx, and hypopharnx (laryngopharynx) with regard to innervation and swallowing. Provide mention of protective reflexes for each region of the pharynx.

Nasopharynx

  • Motor - SVE vagus
  • Sensory - GSA trigeminal
  • Superior constrictor
  • Sneeze reflex
  • Posterior nasal aperature
  • Adenoids
  • Soft palate
  • Auditory tube

Oropharynx

  • Motor - SVE vagus
  • Sensory - GVA glossopharyngeal
  • Middle constrictor
  • Gag reflex

Laryngopharynx

  • Motor - SVE vagus
  • Sensory - GVA vagus
  • Inferior constrictor
  • Cricopharyngeus
  • Cough reflex
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Anatomy of the Carotid Sheath

  1. A 21-year-old woman presents to her physician with a swelling on her neck. On examination, she is diagnosed with an infection within the carotid sheath. Explain the anatomy of carotid sheath, and the structures within it, including the carotid sinus and body. Explain relationships of the carotid sheath.
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Anatomy of the Posterior Triangle and Erb's Point

  1. Explain the anatomy of the posterior triangle, including boundaries, muscles, vessels, and nerves. Include what a mass in the posterior triangle could indicate.
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Anatomy and Relationships of Sternocleidomastoid Muscle

  1. A 22 year-old male enters the ED with his neck twisted to the right and his chin elevated. He complains that he was experiencing neck spasms before going to sleep the night before and woke up with the inability to turn his head, even when manually forced. He explains that he recently started a new medication to treat schizophrenia. Explain spasmodic torticollis, including causes, symptoms, and how it affects neck position.
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Anatomy of the Subclavian Arteries - Omit in lieu of Pancoast Tumor Question

  1. Explain the branches and relationships of the right and left subclavian arteries, including the differences between right and left subclavian.
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Anatomy of the Circle of Willis

  1. Explain the anatomy of the circle of Willis, including its contributions. Include an example of clinical significance.
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Anatomy of the Dural Sinuses

  1. Give a description of the anatomy of the dural venous sinuses, including a how they may be involved in the spread of cancer.
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Anatomy of the Orbit - Omit due to redundancy with previous question.

  1. Explain the anatomy of the orbit. Include a description of an orbital blowout fracture and explain how the patient would present.
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Anatomy of the Parotid Region

  1. A patient comes into your office with a swollen parotid gland. Explain the anatomy of the parotid gland. Explain causes of a swollen gland, include the symptoms a patient may have.
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Anatomy of the Thyroid Gland

  1. Explain the anatomy of the thyroid gland, including innervation, vasculature, and lymphatics. Include an explanation of an anatomical variation of the thyroid gland.
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Anatomy of the Paranasal Air Sinuses - Omit because of redundancy with previous question.

  1. A patient presents with symptoms consistent with sinusitis. Explain the anatomy of the sinuses, including vasculature, innervation, and how infection can spread between sinuses.
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Comments

 
arrowbupTop -- LorenEvey - 05 Oct 2019
Topic revision: r6 - 03 Dec 2019, LorenEvey
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