Suprahyoid And Infrahyoid Neck Flashcards
Suprahyoid neck level
Skull base to hyoid bone, excluding orbit, sinuses and oral cavity
Infrahyoid neck level
Below hyoid bone with some continuing into mediastinum
Contents of suprahyoid neck
Parapharyngeal space Pharyngeal mucosal space Masticator space Parotid space Carotid space Buccal space Retropharyngeal space Perivertebral space
Contents of infrahyoid neck
Visceral space, posterior cervical space, anterior cervical space,
CS, RPS, PVS
From skull base to posterior mandibular space
Parapharyngeal space
Contents of parapharyngeal space
Fat and pterygoid venous plexus
Medial to parapharyngeal space and anterior to retropharyngeal space
Pharyngeal mucosal space
Contents of pharyngeal mycosal space
Mucosa, minor salivary glands, PMS lymphatic ring, constrictor muscles
PMS of nasopharynx
Torus tubarius, adenoids, superior constrictor, levator palatini muscles
PMS of oropharynx
Anterior and posterior tonsillar pillars, palatine and lingual tonsils, soft palate
Anterolateral to PPS
masticator space
Contents of masticator space
Ramus and condyle of mandible
CNV3, masseter, medial and lateral pterygoid and temporalis musles, pterygoid venous plexus
Fascia or masticator space
Superficial layer of deep cervical fascia
Importance of masticator space
Perineural tumor on CNV3, sarcoma
Lateral to PPS
Parotid space
Contents of parotid space
Parotid gland, extracranial CN7, nodes, retromandibular vein, external carotid artery
Posterior to PPS in SHN, lateral to VS and RPS
Carotid space
Carotid space begins at
Inferior jugular foramen and carotid canal or skull base
Carotid space extends inferiorly down to
Aortic arch
Contents of carotid space
CN9-12, internal jugular vein, carotid artery
Fascia or cervical space
All 3 layers of deep cervical fascia
Posterior to PMS in suprahyoid neck and VS in infrahyoid neck
Retropharyngeal space
Contents of retropharyngeal space
Nodes and fat in suprahyoid neck
Retropharyngeal space begins at and ends at
Begins at clivus and ends at T3
Anterior fascia of RPS
Middle layer DCF
Lateral and posterior fascia of RPS
Deep layer DCF/alar fascia
Importance of retropharyngeal space
Inferior communication with danger space allows access to mediastinum
Posterior to RPS and continous inferiorly into mediastinum
Danger space
Behind RPS and around spine in SHN and IHN, defined by skull base above to clavicle below
Perivertebral space
Contents of perivertebral space
Prevertebral and paraspinal components
Fascia of perivertebral space
Deep layer DCF
Traverses visceral space
Trachea and esophagus
Contents of visceral space
Thyroid, parathyroid, paratracheal nodes, esophagus, trachea, recurrent laryngeal nerve
Fascia of visceral space
Middle layer
Posterior cervical space begins at and extends to
Begins at mastoid tip and extends to clavicle
Contents of posterior cervical space
Fat, CN11, spinal accessory nodes
Fascia of posterior cervical space
Between SL and DL
PMS mass displaced PPS
Laterally
MS mass displaces PPS
Posteriorly
PS mass displaces PPS
Medially
CS mass displaces PPS
Anteriorly
Lateral RPS nod mass displaces PPS
Anterolaterally
Foramen ovale contains what nerve
CNV3
Foramen spinosum contains
Middle meningeal artery
Stylomastoid foramen contains
CN7
Jugular foramen contains
Cranial nerves 9-11
“Elevator shaft” thru which infection and tumor from the adjacent neck spaces may travel from skull base to superior cornu of hyoid bone
Parapharyngeal space
Critical contents of parapharyngeal space
Fat Minor salivary glands Internal maxillary artery Ascending pharyngeal artery Pterygoid venous plexus
Attachment area of PMS posteriorly
Basisphenoid (sphenoid sinus floor)
Anterior attachment of PMS
Anterior basiocciput (anterior clivus)
Includes foramen lacerum
PMS
Cartilagenous floor of anterior horizontal petrous internal carotid artery which represent perivascular route for nasopharyngeal carcinoma to access intracranial structures
Foramen lacerum
Lymphatic ring of PMS
Waldeyer ring
Lateral wall of oropharynx in PMS
Palatine (faucial) tonsil
Base of tongue in oropharynx of PMS
Lingual tonsil
Tough aponeurosis that connecta superior constrictor muscle to skull base
Pharyngobasilar fascia
Levator palatini muscle and eustachian tube pass thru this notch on way from skull base to PMS
Sinus of Morgagni/ posterosuperior margin notch
PMS muscles
Superior, middle and inferior constrictor muscles
Salpingopharyngeus muscle
Levator palatini muscle, distal end
Cartilagenous end of eustachian tube found in PMS
Torus tubarius
Fascia of PMS
Middle layer of DCL
Contents of masticator space
Muscles of mastication, posterior body and ramus of mandible
CNV3
Suprazygomatic MS contains
Belly of temporalis muscle
Infrazygomatic masticator space contains
Masseter, medial and lateral pterygoids, CNV3 and ramus/posterior body of mandible
Mandibular division of trigeminal nerve contains
Masticator nerve branch Mylohyoid nerve branch Inferior alveolar nerve branch Lingual nerve Auriculotemporal nerve
Fascia of masticator space
Superficial layer of DCL
Primary tumor of MS
Sarcoma
Contents of parotid space
Parotid glands, nodes, extracranial facial nerve branches
Deep lobe of the parotid gland projects into
Lateral parapharyngeal space
Vessel that is seen just behind the mandibular ramus in parotid space medially
External carotid artery
Vessel that is seen just behind the mandibular ramus in parotid space laterally
Retromandibular vein
Intraparotid facial nerve branches course just lateral to what vessel
Retromandibular vein
Widening of stylomandibular gap indicates the lesion is in what space
Parotid space
Parotid glands appear more fatty in adult or pedia?
Adult
Contents of carotid space
Carotid arteries, internal jugular veins, cranial nerves 9-12
Lower limit of carotid space
Aortic arch
Sympathetic plexus is in between
Medial CS and lateral RPS
Carotid sheath incomplete or less substantial
Suprahyoid carotid space
Carotid sheath is well-defined, tenacious fascia
Infrahyoid carotid space
Midline space just posterior to pharynx and cervical esophagus
Retropharyngeal space
RPS runs from skull base down to what vertebral level
T3
RPS nodes are only found in suprahyoid or infrahyoid neck?
Suprahyoid
Posterior to RPS
Danger space
Lateral to RPS
Carotid space
RPS empties into fascial door trap into what space inferiorly at T3 level
Danger space
Lateral group of RPS lymph nodes also called
Nodes of Rouviere
Anterior to RPS
PMS
Perivertebral space extends from skull base above to what vertebral level
T4 in posterior mediastinum
Prevertebral muscles
Longus colli and capitis
Brachial plexus
C5 to T1
Brachial plexus pass between what muscles of PVS
anterior and middle scalene
Called “the carpet”
Anterior deep layer of DCF
Prevertebral PVS contains
Proximal brachial plexus, phrenic nerve, vertebral arteries
Two major components of PVS
Prevertebral and paraspinal
Most PVS lesions originate in
Vertebral body (infection or metastasis)
Path of least resistance of spreading pus or tumor is deep through
Neural foramen into epidural space
Posterolateral fat-containing space in the neck with complex fascial boundaries
Posterior cervical space
Posterior cervical space extends from
Posterior mastoid tip to clavicle
Lesions from posterior cervical space typically arise from
Spinal accessory nodal chain
Appears as “tilting tent” when viewed on the side
Posterior cervical space
Primary component of posterior cervical space
Fat
Critical contents of posterior cervical space
Fat Accessory nerve (CN11) Spinal accessory lymph node chain (level 5A and 5B) Pre-axillary brachial plexus Dorsal scapular nerve
Region of cervical neck posterolateral to sternomastoid muscle and anteromedial to trapezius muscle
Posterior triangle
Posterior triangle is subdivided by
Inferior belly of omohyoid (into occipital and subclavian triangles)
Two triangles in posterior cervical space
Occipital triangle and subclavian triangle
Majority of posterior cervical space is what triangle
Occipital triangle
Most commonly injured during neck dissection for malignant sCCa nodes
CN11
Midline infrahyoid neck space enclosed by middle layer DCF
Visceral space
Visceral space extends from
Hyoid bone above to superior mediastinum below
Contents of visceral space
Larynx, trachea, hypopharynx, esophagus, thyroid and parathyroid glands
Largest space of infrahyoid neck
Visceral space
Less reliable location of parathyroid glands, superior or inferior?
Inferior
Inferior parathyroid glands may be normally found in
Cervicothoracic junction or superior mediastinum
Left recurrent laryngeal nerve recurs at
Level of arch where it passes through the aortopulmonic window
Right recurrent laryngeal nerve recurs in
Most inferior infrahyoid neck around right subclavian artery
Visceral lymph nodes is what level
Level VI
First order of drainage for thyroid malignancy
Paratracheal lymph nodes (level VI)
Also referred to as visceral fascia
Middle layer DCF
Mass centered between thyroid love anteriorly and longus colli muscle posteriorly
Parathyroid (tracheoesophageal groove) mass lesion
Caudal continuation of pharyngeal mucosal space, between oropharynx and esophagus
Hypopharynx
Junction of upper and lower airway
Larynx
Hypopharynx extends from level of glossoepiglottic and pharyngoepiglottic folds superiorly to
Inferior cricoid cartilage (cricopharyngeus muscle)
Hypopharynx: oropharynx above, ____________ below
Esophagus
Larynx: oropharynx above, ___________ below
Trachea
3 regions of hypopharynx
Pyriform sinus
Posterior wall
Post-cricoid region
Anterolateral recess of hypopharynx, between inner surface of thyrohyoid membrane above, thyroid cartilage below and lateral aryepiglottic fold
Pyriform sinus
Anterior wall of lower hypopharynx
Post-cricoid region
Provides all motor and most sensory to hypopharynx
Pharyngeal plexus (CN9-10)
Laryngeal cartilages
Thyroid, cricoid, arytenoid, corniculate
Largest laryngeal cartilage
Thyroid cartilage
Only complete ring in endolarynx, provides structural integrity
Cricoid cartilage
Paired pyramidal cartilages that sit atop posterior cricoid cartilage
Arytenoid cartilage
Rests on top of superior process of arytenoid cartilage, within AE folds
Corniculate cartilage
Extends from tip of epiglottis above to laryngeal ventricle below
Supraglottis
Leaf-shaped cartilage, larynx lid with free margin and fixed portion
Epiglottis
Free margin of epiglottis is at
Suprahyoid
Fixed portion of epiglottis
Infrahyoid
Fat-filled space between hyoid bone anteriorly and epiglottis posteriorly
Pre-epiglottic space
Projects from cephalad tip of arytenoid cartilages to inferolateral margin of epiglottis
Aryepiglottic fold
Mucosal surfaces of laryngeal vestibule of supraglottis
False vocal cords
Paired fatty regions beneath fals and true vical cords
Paraglottic spaces
Contains true vocal cords and anterior and posterior commisures
Glottis
Only soft tissue structures of glottic region, comprised of thyroarytenoid muscle
True vocal cord
Fibroelastic membrane extends from medial margin of TVC above to cricoid below
Conus elasticus
Fibrous membrane extends from upper arytenoid and corniculate cartilages to lateral margin epiglottis and medial margin of paraglottic space
Quadrangular membrane
Formed from primitice buccopharyngeal anlage and has rich lymphatics
Supraglottic larynx
Forms from tracheobronchial buds and has few lymphatics
Glottic and subglottic larynx
Pyramidal lobe of thyroid gland can be seen from
Isthmus area toward hyoid bone
Thyroid glands extends from C5 to
T1
Arterial supply to thyroid gland
Superior thyroid arteries, inferior thyroid arteries, thyroidea ima
1st anterior branch of external carotid artery
Superior thyroid artery
Arises from thyrocervical trunk, a branch of subclavian artery
Inferior thyroid artery
Runs superficially on anterior border of lateral thyroid lobe, with its proximal course closely associated with superior laryngeal nerve
Superior thyroid arteries
Most of its branches penetrate posterior aspect of lateral thyroid lobe with close association with recurrent laryngeal nerve
Inferior thyroid artery
Single vessel originating from aortic arch or innominate artery, which enters the thyroid gland at inferior border of isthmus
Thyroidea ima
Venous drainage of thyroid gland
Superior, middle and inferior thyroid veins
Superior and middle thyroid veins drain into
Internal jugular vein
Inferior thyroid vein drain into
Left brachiocephalic vein
Lymphatic drainage of thyroid gland
Level 6
Fascia or thyroid gland
Middle later DCF and true capsule
First endocrine gland to develop
Thyroid gland
Thyroid gland originates as proliferation of endodermal epithelial cells on median surface of developing pharyngeal floor termed
Foramen cecum
Most common location of ectopic thyroid gland
Deep to foramen cecum in tongue base= lingual thyroid
Posterior visceral space endocrine glands that control calcium metabolism by producing parathormone
Parathyroid gland
Superior parathyroid gland normal locations
Posterior border of middle 1/3 of thyroid (75%)
Inferior parathyroid gland normal locations
Lateral to lower pole of thyroid gland (50%)
Arterial supply of parathyroid gland
Superior thyroid artery and inferior thyroid artery
Fascia of parathyroid gland
Middle DCF
Superior parathyroid gland develops from
4th branchial pouch
Inferior parathyroid gland develops from
3rd branchial pouch
Most frequent ectopic site of parathyroid gland
Just below inferior thyroid pole
Trachea extends in midline from inferior larynx at what vertebral body level to what level
C6 to T5 (carina)
Tracheal length
10-13 cm
Length of esophagus and extent
25 cm
From C6 to T11
Broadest of all tracheal cartilage
First tracheal cartilage
Blood supply of trachea
Inferior thyroid artery and vein
Upper limit of esophagus
Cricopharyngeus muscle
Blood supply of esophagus
Inferior thyroid artery and vein
Sentinel or highest node found at apex of internal jugular chain at angle of mandible
Jugulodigastric node
Node found at bottom of internal jugular chain in supraclaviculsr fossa
“Signal” Virchow node
Level IA nodes, found between anterior bellis of digastric muscles
Submental
Level IB nodes, found around submandibular glands in submandibular space
Submandibular nodes
Level 2 nodes from posterior belly of digastric muscle to hyoid bone
Upper internal jugular chain
Contains the jugulodigastric nodal group
Level 2A
Level 3 nodes from hyoid bone to inferior margin of cricoid
Mid IJC nodes
Level 4 nodes from inferior cricoid margin to clavicle
Lower internal jugular chain
Nodes of posterior cervical space or spinal accessory chain
Level 5
Level 5A nodes are from skull base to
Bottom of cricoid cartilage
Nodes of visceral space
Level 6
Superior mediastinal nodes
Level 7
Parotid nodal group drain into
Level 2
Retropharyngeal nodal group recieve drainage from
Posterior pharynx
Final commin pathway for all lymphatics of upper aerodigestive tract and neck
Internal jugular chains
