Download Unit II Structures to ID

Structures to Identify: Head & Neck Practical
Lab 1: Scalp, Interior of Skull, Dural Partitions and Sinuses, and Cranial Fossae
 Scalp:
o 5 layers:
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Skin, Connective Tissue (dense), Aponeurosis, Loose Connective Tissue, Pericranium
o Occipitofrontalis muscle
o Temporalis muscle
o Supraorbital nerve and vessels; if present, steps to find them:
 Pull anterior scalp flap inferiorly to see supraorbital margin
 Nerve and vessels exit supraorbital notch and enter deep surface of scalp
Calvaria
o Groove for superior sagittal sinus
o Granular foveolae—caused by arachnoid granulations
o Grooves for the branches of the middle meningeal artery
Dural partitions
o Cerebellar tentorium
o Falx cerebri
o Falx cerebelli
Dural sinuses
o Superior sagittal sinus—begins near crista galli and ends near cerebellar tentorium
o Confluence of sinuses—at internal occipital protubernce
o Inferior sagittal sinus—inferior margin of falx cerebri
o Straight sinus—at junction of falx cerebri and tentorium cerebri
o Great cerebral vein of Galen—at anterior end of straight sinus
o Transverse sinus—will see groove on occipital bone
o Sigmoid sinus—will see groove on occipital bone; ends at jugular foramen
o Sphenoparietal sinus
o Cavernous sinus
o Superior pretrosal sinus
o Inferior petrosal sinus
o Basilar plexus
Anterior Cranial Fossa: sphenoid, ehtmoid, frontal bones
o Cribiform plate and [I]
o Crista galli
o Anterior clinoid process
Middle Cranial Fossa: sphenoid and temporal bones
o Foramen spinosum and Middle meningeal artery
o Optic canal and [II]
o Superior orbital fissure and [III], [IV], V1, [VI]
o [V] and ganglion
o Foramen rotundum and V2
o Foramen ovale and V3
o Carotid canal and internal carotid artery: carotid siphon in the cavernous sinus
o Hypophyseal fossa, covered by diaphragm sellae
o Anterior and posterior intercavernous sinuses: surrounds stalk of pituitary
o Posterior clinoid process
Posterior Cranial Fossa: temporal and occipital bones
o Internal acoustic meatus and [VII] and [VIII]
o Jugular foramen: [IX], [X], and [XI]
o Foramen magnum: cervical root of [XI] enters fossa here
o Groove for transverse sinus and groove for sigmoid sinus
o Hypoglossal canal and [XII]
Lab 2: Neck, Posterior Triangle
 Boundaries of Posterior Triangle:
o Anterior: posterior border of SCM
o Posterior: superior border of trapezius
o Inferior: middle 1/3 of clavicle
o Roof: investing layer of deep cervical fascia
o Floor: muscles of the neck (scales, levator scapulae) and prevertebral fascia
 Platysma muscle—in superficial fascia, innervated by cervical branch of [VII]
 External jugular vein
 Branches of cervical plexus:
o Lesser occipital nerve
o Great auricular nerve
o Transverse cervical nerve
o Supraclavicular nerve—review referred diaphragmatic pain to shoulder (Grant’s pg. 208)
 [XI]
Lab 3: Anterior Triangles (Muscular, Submandibular, and Submental)
 Bones and cartilage: Hyoid, thyrohiod membrane, laryngeal prominence of thyroid cartilage, cricoid
cartilage, first tracheal ring, isthmus of thyroid gland
 In superficial fascia:
o Find retromandibular vein & posterior auricular vein uniting to form external jugular
o Anterior jugular vein
o Communicating vein (connects common facial vein w/ anterior jugular vein)
 Muscular Triangle
o Bounderies:
 Superolateral: superior belly of omohyoid
 Inferolater: anterior border of SCM
 Medial: median plane of neck
o Muscles: sternohyoid, superior belly of omohyoid, sternothyroid, thyrohyoid
o Ansa cervicalis: innervates 3 of 4 infrahyoids
o Nerve to thyrohyoid: from C1, via [XII]
 Submandibular Triangle
o Boundaries:
 Superior: inferior border (base) of mandible
 Anteroinferior: anterior belly of the digastric
 Posteroinferior: posterior belly of the digastric
 Roof: investing layer of fascia
 Floor: mylohyoid and hyoglossus
o On mandible:
 Digastric fossa
 Mylohyoid line
 Submandibular fossa
 Mylohyoid groove
o Muscles:
 Anterior/posterior bellies of digastric; intermediate tendon
 Tendon of stylohyoid
 Mylohyoid muscle
o [XII]: enters triangle deep to the posterior belly of digastric, then passes deep to mylohyoid
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Submental Triangle
o Boundaries:
 Lateral: anterior bellies of right/left digrastric muscles
 Inferior: hyoid bone
 Roof: investing fascia
 Floor: mylohoid
o Submental lymph and tributaries that form the anterior jugular vein
Lab 4: Carotid Triangle, Thryoid and Parathyroid
 Boundaries of Carotid Triangle:
o Anterior: superior belly of omohyoid
o Posterior: anterior border of SCM
o Superior: posterior belly of digastric and stylohyoid
o Floor: posterior—inferior pharyngeal constrictor; anterior—thyrohyoid and hyoglossus
o Roof: Investing fascia, cutaneous nerves, and platysma
 [XI]: look for it on deep surface of SCM
 Greater horn of hyoid bone
 [XII]: Superior to tip of greater horn of hyoid; crossed superiorly by occipital artery; passes medial to
posterior belly of digastric, medial to stylohyoid, and deep to mylohyoid
 Ansa cervicalis
o Superior root travels with [XII]
o Inferior root passes lateral to carotid sheath
 Thyrohyoid membrane
 Superior laryngeal nerve
o Internal branch: sensory to mucosa of larynx superior to vocal folds
o External branch: motor to cricothyroid
 Cricothyroid muscle
 Carotid sheath: common carotid, internal carotid, internal jugular, and [X]
o IJV tributaries: common facial vein, superior thyroid vein, middle thyroid vein
 External carotid artery and branches:
o Superior thyroid: gives off superior laryngeal (runs with internal laryngeal nerve)
o Lingual: passes deep to muscles of tongue
o Facial: passes medial to posterior belly of digastric and deep to superficial submandibular gland
o Occipital artery
o Posterior auricular artery
o Ascending pharyngeal artery
 Birfurcation of common carotid & carotid sinus and body
 [X]: posterior to the vessels
 Thyroid: @ C5-T1
o Right and left lobe, connected by isthmus
o Look for pyramidal lobe: would extend superiorly from isthmus
o Superior thyroid artery; enters superior end of lobe
o Superior and middle thyroid veins
o Right/Left inferior thyroid veins
o Thyroid ima (rare): would enter thyroid gland inferiorly, near midline
o Recurrent laryngeal nerve: posterior to lobe; in groove between trachea & esophagus
 Parathyroid: posterior aspect of thyroid (if you’ve dissected one of the lobes)
Lab 5: Root of Neck
 Junction between thorax and neck; superior to superior thoracic aperture
 Inferior belly of omohyoid and intermediate tendon
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External jugular vein
Subclavian vein
o Joined by internal jugular vein to form the brachiocephalic vein
Subclavian artery
o Right: branch off brachiocephalic trunk
o Left: branch off aortic arch
o Branches (location where branches come off will vary):
 First part—from origin to medial border of anterior scalene
 Vertebral artery
 Internal thoracic artery
 Thyrocervical trunk
o Transverse cervical artery
o Suprascapular artery
o Inferior thyroid artery
 Ascending cervical artery
 Second part—posterior to anterior scalene
 Costocervical trunk
o Deep cervical artery
o Supreme intercostal artery—gives rise to posterior intercostal arteries 1 & 2
 Third part—between lateral border of anterior scalene & lateral border of rib 1
 Dorsal scapular artery
Thoracic duct: on left side; joins venous system near junction of right subclavian and IJV
Lymphatic duct: right side; drains into junction of left subclavian and IJV
[X]: passes posterior to root of lung
Right recurrent laryngeal: comes off after [X] passes anterior to subclavian artery
Left recurrent laryngeal: comes off after [X] passes on the left side of the aortic arch
Phrenic nerve: crosses anterior surface of the anterior scalene muscle
Sympathetic trunk: cervical portion; inferior cervical sympathetic ganglion is low in neck
Floor of posterior triangle: splenius capitis, levator scapulae, scales
Interscalene triangle: first rib and adjacent borders of anterior and middle scalene muscles
Roots of brachial plexus & subclavian artery: pass thru interscalene triangle between anterior and middle
scalene muscles
o Supraclavicular portion of brachial plexus: five roots, three trunks, six divisions
Subclavian vein, transverse cervical artery, and suprascapular artery: cross anterior surface of anterior
scalene muscle
Phrenic nerve: descends vertically across anterior surface of anterior scalene muscle
Lab 6: Head, Face, and Parotid Region
 Platysma: small part extends into face along inferior border of mandible
 Parotid gland and parotid duct: duct pierces buccinators muscle
o Enclosed in parotid sheath (continuous with investing fascia)
 [VII]: forms parotid plexus within parotid gland
o Branches:
 Posterior auricular
 Temporal
 Zygomatic
 Buccal
 Marginal mandibular
 Cervical
 Buccal fat pad: anterior to masseter muscle (may be different consistency than regular fat)
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o Buccal nerve of V3 emerges deep to masseter muscle
Facial artery: crosses inferior border of mandible @ anterior border of masseter
o Branches
 Inferior labial artery
 Superior labial artery
 Angular artery: continuation of facial artery @ lateral side of nose
Facial vein: straighter, posterior to facial artery
o Angular vein anastomoses with ophthalmic veins in orbit (might see in prosection)
Muscles: Buccinator muscle, masseter muscle, orbicularis oculi (orbital and palpebral part), levator labii
superioris, zygomaticus major/minor, orbicularis oris, buccinators, depressor anguli oris
Supraorbital nerve
Infraorbital nerve: covered by levator labii superioris
o Infraorbital artery and vein related to nerve
Mental nerve
o Mental artery and vein related to nerve
Auriculotemporal nerve: often loops middle meningeal artery
Retromandibular vein: find where it is formed by joining of maxillary vein and superficial temporal vein
Superficial temporal vein
Maxillary artery and superficial temporal arteries
Lab 7: Temporal and Infratemporal fossae
 Skeletal structures to identify for this region:
o Temporal fossa—formed by parts of four cranial bones
 Parietal, frontal, squamous temporal, and greater wing of sphenoid
o Superior and inferior temporal lines—on parietal bone
o Zygomatic arch—formed by zygomatic process of temporal bone and temporal process of zygomatic
bone
o Mandibular fossa and articular tubercle—on temporal bone
o On Mandible:
 Head (condyle), neck, mandibular notch, coronoid process, ramus, and angle
 Lingula: attachment for sphenomandibular ligament
 Mandibular foramen: for inferior alveolar nerves and vessels
 Mylohyoid groove: for nerve to mylohyoid and mylohyoid vessels
o Pterygomaxillary fissure—between lateral pterygoid plate and maxilla
o Pterygopalatine fossa—at superior end of PT fissure
o Sphenopalatine foramen—passage from PT fossa to nasal cavity
o Inferior orbital fissure—between greater wing of sphenoid and maxilla
o Infratemporal surface of the maxilla
o Greater wing of the sphenoid—contains foramen ovale and formaen spinosum
o Lateral pterygoid plate of pterygoid process—on sphenoid
 Temporal fossa:
o Boundaries:
 Superior and posterior: superior temporal line
 Anterior: forntal and zygomatic bones
 Inferior: zygomatic arch (superficially) and infratemporal crest of sphenoid bone (deeply)
 Deep: Parts of the frontal, parietal, temporal, and sphenoid bones
o Temporalis muscle: sup. attachment is temporal fascia and surface of fossa; inf. attachment is
coronoid process of mandible; ant. fibers elevate mandible, post. fibers retract mandible
 Infratemporal fossa:
o Boundaries:
 Superior: zygomatic arch (superficially), infratemporal crest of sphenoid bone (deeply)
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 Anterior: infratemporal surface of maxilla
 Lateral: ramus of mandible
 Medial: lateral plate of the pterygoid process
o Masseter muscle: sup. attachment is inf. border of zyg. arc; inf. attachment is lateral surface of
ramus and mandible
 Masseteric vessels and nerve: cross superior to mandibular notch to enter deep surface of
muscle
o Mandibular nerve (V3) and branches:
 Inferior alveolar: enters mandibular foramen and passes anteriorly to mandibular canal and
provides sensory innervation the mandibular teeth
 Mental: passes through the mental foramen to innervate chin and lower lip
 Lingual
 Buccal
 Auriculotemporal
 Deep temporal
 Mylohyoid
o Chorda Tympani: joins posterior side of lingual nerve high in IT fossa
o Maxillary artery and branches:
 Middle meningeal
 Deep temporal (anterior and posterior)
 Masseteric
 Inferior alveolar
 Buccal
 Posterior superior alveolar artery: enters infratemporal surface of the maxilla
o Medial and lateral pterygoid muscles
Temporomandibular joint
o Joint capsule: loose, reinforced laterally by lateral ligament
o Lateral ligament
o Articular disc and superior/inferior synovial cavities
 Hinge motion: inferior cavity between head of mandible and articular disc
 Gliding motion: superior cavity between articular disc and mandibular fossa
o Tendon of lateral pterygoid muscle: attaches to neck of mandible and articular disc
Lab 8: Disarticulation of the head, pharynx, and bisection of head
Disarticulation
 ID the following on occipital bone/posterior cranial fossa:
o Hypoglossal canal, occipital condyle, basilar part, pharyngeal tubercle, foramen magnum, external
occipital protuberance; grooves for sigmoid and transverse sinuses, and superior border of petrous
portion of temporal bone
 Retropharyngeal space: boundaries?
o Structures passing through foramen magnum:
 Brainstem, vertebral arteries, cervical roots of [XI]
o [XII] passing through hypoglossal canal
o Structures entering the jugular foramen:
 [IX], [X], [XI], and sigmoid sinus/jugular vein
 Prevertebral and lateral vertebral regions:
o Sympathetic trunk
 Superior, middle and inferior cervical ganglia
 Gray rami communicantes
 Cervicothoracic (stellate) ganglion
o Internal carotid nerve
o Anterior scalene muscle
Pharynx
 Pharyngeal wall layers
o Buccopharyngeal fascia
o Muscular layer
o Mucous membrane
 Muscles:
o Inferior pharyngeal constrictor: pharyngeal raphe
o Middle pharyngeal constrictor: pharyngeal raphe
o Superior pharyngeal constrictor: pterygomandibular raphe (ant. att.); pharyngeal tubercle (post. att.)
 Pharyngobasilar fascia
o Stylopharyngeus muscle
 [IX] relationship to stylopharyngeus
 Pharyngeal plexus of nerves
 Contents of carotid sheath
o Relationship to sympathetic trunk and superior cervical sympathetic ganglion?
 [IX], [X], and [XI] at jugular foramen
o Superior laryngeal nerve and pharyngeal branch of [X]
 [XII] from submandibular triangle to base of skull
 Internal carotid nerve
Bisection
 ID bisected structures: nasal bone, frontal bone, cribiform plate, body of sphenoid, hard palate, basilar part
of occipital bone as far as the foramen magnum
 Parts of the pharynx:
o Nasopharynx: Boundaries?
 Posterior nasal aperture (choana)
 Opening of the pharyngotympanic tube (aka auditory tube aka eustachian tube)
 Torus tubarius
 Salpingopharyngeal fold
 Pharyngeal recess
 Pharyngeal tonsil (adenoid)
o Oropharynx: Boundaries?
 Palatoglossal fold
 Fauces: transitional region between oral cavity and oropharynx
 Palatopharygneal fold
 Palatine tonsil
o Laryngopharynx: Boundaries?
 Epiglottis
 Aditus of the larynx
 Piriform recess: borders? (Medial=larynx; lateral=thyroid cartilage; post.=inf. constrictor)
Lab 9: Nose, Nasal Cavity, and Hard/Soft Palate
 Skeleton of nasal cavity: find these from anterior view of skull
o Nasal Bone
o Lacrimal bone
o Maxila
 Frontal process
 Anterior nasal aperture
 Anterior nasal spine
o Nasal septum—bony part
o Middle nasal concha
o Inferior nasal concha
 Skeleton of lateral nasal wall:
o Ethmoid bone
 Cribiform plate
 Superior nasal concha
 Middle nasal concha
o Lacrimal bone
o Inferior nasal concha
o Maxilla
 Palatine process
 Incisive canal
o Sphenoid bone
 Opening of the sphenoidal sinus
 Sphenoidal sinus
 Body
 Medial/Lateral plates of the pterygoid process
o Palatine bone
 Perpendicular plate
 Horizontal plate
o Sphenopalatine foramen
External nose
 Septal cartilage
o Lateral nasal cartilage
 Alar cartilage
 Boundaries of nasal cavity
Nasal septum
 Perpendicular plate of ehtmoid bone
 Vomer
 Septal Cartilage (ID it stripped of mucosa)
 Nasopalatine nerve: runs from sphenopalatine foramen to the incisive canal
 Sphenopalatine artery: same course as nasopalatine n.; Grant’s says this artery going thru incisive canal…
 Olfactory area: mucosa near cribiform plate
Lateral wall of nasal cavity
 Sphenoethmoidal recess
o Opening of the sphenoidal sinus
 Sphenoidal sinus—directly inferior to hypophyseal fossa and pituitary gland
 Superior/middle/inferior concha
 Superior/middle/inferior meatus
 Vestibule
 Atrium
 Nasolacrimal duct: opening in inferior meatus
 Semilunar hiatus: in middle concha
o Opening of the maxillary sinus
o Opening of the frontal sinus/anterior ethmoidal cells (in infundibulum)
 Ethmoidal bulla: in middle concha
o Opening of the middle ethmoidal cells
 Opening of the posterior ethmoidal cells in the superior meatus
 Ethmoidal cells: located between nasal cavity and orbit
 Maxillary sinus:
o Roof is the floor of orbit; infraorbital nerve innervates sinus mucosa
o Floor is alveolar process of maxilla; roots of teeth project into sinus
Hard and Soft Palates
 Skeleton of the palate:
o Maxilla:
 Incisive foramen
 Alveolar process
 Palatine process
o Palatine bone:
 Horizontal plate
 Greater palatine foramen
 Lesser palatine foramina
 Posterior nasal spine
o Sphenoid bone:
 Hamulus of the medial plate of the pterygoid process
 Medial/lateral plate of pterygoid process
 Scaphoid fossa
 Pterygoid canal
o Inferior orbital fissure
o Sphenopalatine foramen
o Pterygopalatine fossa
o Pterygomaxillary fissure
Soft Palate
 Torus tubarius
 Opening of the pharyngotympanic tube
 Salpingopalatine fold
 Torus levatorius
 Salpingopharyngeal fold
 Palatoglossal fold
 Palatopharyngeal fold
 Palatine tonsil
 Muscles: Innervated by pharyngeal plexus of [X] or V3
o Palatoglossus: sup. att.=palatine aponeurosis; inf. att.=lateral side of tongue
o Palatopharyngeus: sup. att.=hard palate & aponeurosis; inf. att.=thyroid cartilage & pharyngeal wall
o Salpingopharyngeus: sup. att.=cartilage of auditory tube; inf. att.=same as palatopharyngeus
 Blends with palatopharyngeus; both are inner longitudinal muscles of pharynx
o Stylopharyngeus: anterior and parallel to palatopharyngeus and salpingopharyngeus
 Those three muscles blend near inferior end
 Stylopharyngeus enters pharynx between superior and middle pharyngeal constrictors
o Pharyngobasilar fascia: closes gap between superior constrictor and base of skull
 Auditory tube and levator veli palatini pass through this gap
o Levator veli palatini: sup. att.=cartilage/temporal bone of auditory tube; inf. att.=aponeurosis
o Tensor veli palatini: sup. att.=scaphoid fossa; belly btwn. medial/lateral pterygoid plates
 tendon turns medially around hamulus of medial plate and forms palatine aponeurosis
 Pharyngotympanic tube: 2/3 cartilaginous (pharynx side); 1/3 temporal bone (middle ear side)
 Greater palatine nerve and artery: emerge from greater palatine foramen
 Nasopalatine nerve and distal end of sphenopalatine artery
 Lesser palatine nerve and artery
 Tonsillar bed: houses palatine tonsil
o Boundaries?
 [IX]: enters tonsillar bed between superior and middle constrictors
Sphenopalatine foramen and PT fossa
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Sphenopalatine artery branches (not dissected): posterior lateral nasal arteries and posterior septal branch
Sphenopalatine foramen
Greater palatine canal contents: greater palatine nerve, lesser palatine nerve, and descending palatine artery
o Descending palatine artery gives rise to greater/lesser palatine arteries
Pterygopalatine ganglion
Nerve to pterygoid canal
Deep to IT fossa:
o Maxillary artery
 Sphenopalatine artery
 Descending palatine artery
 Infraorbital artery: through inferior orbital fissure to enter infraorbital canal, emerges on face
at infraorbital foramen
o V2
Lab 10: Oral region and larynx
Surface anatomy of oral vestibule
 Maxilla: alveolar process and anterior surface
 Mandible: alveolar process and coronoid process (with tendon of temporalis muscle)
 Masseter muscle
 Communication between oral vestibule and oral cavity proper: posterior to third molar tooth
 Frenulum
 Opening of the parotid duct (lateral to second maxillary molar)
Surface anatomy of oral cavity proper: Boundaries?
 Tongue: body, apex, median sulcus
 Sublingual area: frenulum, sublingual folds, opening of submand. duct on caruncle, & deep lingual veins
Tongue
 Root (pharyngeal tongue): lies more vertically
o Median/Lateral glossoepiglottic fold
o Epiglottic vallecula
 Body (oral tongue): lies more horizontally
 Apex
 Dorsum
o Sulcus terminalis
o Lingula tonsil
o Foramen cecum
o Median sulcus
o Lingual papillae: four types
 Bisection of tongue and mandible: Find mylohyoid, geniohyoid, and genioglossus msucles
Sublingual region
 Sublingual gland: rests on mylohyoid muscle
 Submandibular duct: opens on the sublingual caruncle
 Deep part of the submandibular gland: on deep side of mylohyoid
 Lingual nerve: passes lateral, inferior, and then medial to submandibular duct
 Submandibular ganglion: near third mandibular molar tooth
 [XII]: passes btwn. deep part of submandibular gland and the hyoglossus; btwn. hyoglossus and
mylohhyoid
o it’s course is inferior to course of lingual nerve
 Hyoglossus: inf. att.=body and greater horn of hyoid; sup. att.=lateral side of tongue
 Styloglossus: inf. att.=lateral side of tongue; sup. att.=styloid process
 Intrinsic muscles of tongue: vertical, transverse, superior/inferior longitudinal groups of fibers
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Lingual artery: passes medial to hyoglossus muscle
o Gives off sublingual artery, and after that name changes to deep lingual artery
Larynx
 Skeleton of the larynx:
o Epiglottic cartilage
 Stalk: attached to inner surface of the angle formed by the thyroid laminae
o Thyrohyoid membrane
o Thyroid cartilage: formed by two laminae joined in ant. midline
 Laryngeal prominence
 Superior horn
 Inferior horn—articulates w/ cricoid cartilage through cricothyroid joint
o Cricoid cartilage: lamina is posterior, arch is anterio
o Arytenoid cartilages
 Muscular and vocal processes
o Vocal ligaments
Intrinsic muscles of the larynx
 Cricothyroid muscle
 Lamina of the cricoid cartilage
 Piriform recess
 Internal branch of the superior laryngeal nerve
 Inferior laryngeal nerve
 Posterior cricoarytenoid muscle
 Arytenoid muscle
o Transverse and oblique fibers
 Cricothyroid joint
o Recurrent laryngeal passes posteriorly and name changes to inferior laryngeal nerve
 Lateral cricoarytenoid muscle
 Thyroarytenoid muscle
o Vocalis muscle (not seen in dissection): formed by medial fibers; attached to vocal ligament
 Vocal folds: rima glottidis and glottis
Interior of the larynx
 Laryngeal cavity: Vestibule, ventricle (may extend into a recess called the saccule), and infraglottic cavity
 Epiglottis
 Vestibular fold—false vocal fold
 Vocal fold—true vocal fold
o Vocal ligament
 Internal branch of superior laryngeal nerve
 External branch of superior laryngeal nerve
 Inferior laryngeal branch of the recurrent laryngeal nerve