NECK and CERVICAL LYMPHATICS

Miranda, Rmin Sheila J.Medicine 2009 (August 2008)

OVERVIEW

Function Topographic Anatomy Fascial Layers Neck Triangles Cervical Lymphatics

THE NECK

Communication between head and body: For air For food For speech

Contains: Major blood vessels Nerves and the spinal cord Cervical lymphatics

For maximal mobility to permit variation in head position relative to body

Topographic Anatomy

Superior: inferior border of the mandible tip of the mastoid process external occipital protuberance

Lateral: sternocleidomastoid muscles trapezius muscles

Medial: hyoid bone thyroid cartilage cricoid cartilage thyroid gland (if enlarged)

Inferior: suprasternal notch upper border of the clavicle

Fascial Layers of the Neck

Superficial Fascia Thin layer that encloses platysma ms. Contains cutaneous vessela and nodes

Deep Cervical Fascia (Fascia Colli) Superficial investing

Complete encircles the neck Encloses SCM and trapezius ms Roofs over Anterior and Posterior neck triangles

Pretracheal layer Encloses infrahyoid ms, thyroid and parathyroid glands Blends inferiorly with fibrous pericardium

Prevertebral layer Covers prevertebral ms

Fascial Layers of the Neck

Pretracheal Fascia

Superficial Fascia

Prevertebral Fascia

Superficial InvestingFascia

Fascial Layers of the Neck

Pretracheal Fascia

Superficial Fascia

Prevertebral Fascia

Superficial InvestingFascia

Neck Triangles

Anterior Neck Triangle

Borders A: midline of the neck P: anterior border of SCM S: lower margin of the mandible

Divided by Anterior & Posterior bellies of

digastric muscle Superior belly of omohyoid muscle

Subdivisions Submental triangle Digastric/submandibular triangle Carotid triangle Muscular triangle

Subdivisions of ANT

Submental Triangle

Borders anterior belly of digastric ms,

hyoid, and midline floor formed by 2 Mylohyoid ms

Contents submental lymph nodes

Subdivisions of ANT

Digastric / Submandibular Triangle

Borders: mandible, anterior and posterior belly of digastric ms floor formed by the mylohyoid and hyoglossus muscles

Contents: A: submandibular salivary gland, facial artery, facial vein, and

submandibular lymph nodes I: Nerve and vessels to the mylohyoid muscles P: carotid sheath with the carotid arteries, internal jugular vein, and

vagus nerve Lower part of the parotid gland projects into the triangle Hypoglossal nerve runs on the hyoglossus muscle

Subdivisions of ANT

Carotid Triangle

Borders: Posterior belly of digastric ms, superior belly of omohyoid ms, and

anterior border of SCM Floor formed by portions of the thyrohyoid, hyoglossus, and middle

and inferior constrictor muscles of the pharynx

Contents: carotid sheath (where common carotid artery divides into ICA & ECA) branches of ECA internal jugular vein hypoglossal nerve, laryngeal nerves, accessory and vagus nerves part of the chain of deep cervical lymph nodes

Subdivisions of ANT

Muscular Triangle

Borders: A: midline of neck S: superior belly of omohyoid ms I: anterior border of SCM Floor formed by the sternohyoid and sternothyroid ms.

Contents: thyroid gland larynx trachea

Posterior Neck Triangle

Borders A: posterior border of SCM P: anterior border of trapezius ms I: middle third of the clavicle

Divided by Inferior belly of omohyoid ms

Subdivisions Occipital triangle Supraclavicular triangle

Subdivisions of PNT

Supraclavicular Triangle

Borders A: posterior border of SCM P: inferior belly of omohyoid ms I: clavicle

Contents Superficially crossed by the suprascapular artery with the subclavian

artery deeper inside

Subdivisions of PNT

Occipital Triangle

Borders A: posterior border of SCM P: anterior border of trapezius ms I: inferior belly of the omohyoid

Contents Occipital artery appears at its apex Crossed by the accessory nerve

CERVICAL LYMPHATICS

Cervical LN Groups

HEAD LYMPHATIC NODES

Efferent drainage: cervical nodes

1-3 occipital nodes: back of head

2 post-auricular: insertion site of SCM

Pre-auricular: anterior to tragus

Parotid nodes Superficial nodes: within

gland substance Deep nodes: lateral wall of

the pharynx

HEAD LYMPHATIC NODES

Deep cervical chain through the submandibular nodes Infra-orbital Buccinators Supramandibular Submental nodes

Primary deep lymphatic chains of the neck Internal jugular spinal accessory transverse cervical are the

INTERNAL JUGULAR CHAIN

Chief collecting system 10-20 nodes on each

side Highest: parapharyngeal

and retropharyngeal nodes

Superior group Anterior or lateral to IJV Most frequently involved in

aerodigestive squamous cell CA

Inferior group Anterior and medial to IJV Close to trachea

TRANSVERSE CERVICAL CHAIN

4-12 nodes Connects spinal accessory

with internal jugular chain Empty into lymphatic trunk

L: thoracic duct R: lymphatic duct

Supraclavicular (Virchov’s) nodes receive lymph from: below the clavicles head and neck upper extremities

CERVICAL LN GROUPS

Level I Submental &

Submandibular group Level II

Upper jugular group Level III

Middle jugular group Level IV

Lower jugular group Level V

Posterior triangle group Level VI

Anterior compartment group

LEVEL IA: Submental nodes

3-4 Between anterior belly of

digastric ms Drains:

incisor region of lower gums Lips tip of tongue ventral part of mouth floor skin of cheek

Efferents to submandibular nodes and deep cervical chain

LEVEL IB: Submandibular nodes

3-6 inferior border of mandible Drains:

medial palp. eye commissure cheek and chin side of nose upper and lateral lower lip gums and teeth anterior part of tongue margin (not

tip) paranasal sinuses

Efferent vessels pass to superficial and superior deep cervical nodes

Boundaries: Body of the mandible Anterior belly of contralateral

digastric muscle Anterior & Posterior bellies of

ipsilateral digastric muscle

LEVEL II: UPPER JUGULAR

At upper 1/3 of IJV, near SAN extending from :

level of carotid bifurcation (surgical landmark) or

hyoid bone (clinical landmark) inferiorly to skull base superiorly

L: Posterior border of SCM M: Lateral border of sternohyoid &

stylohyoid ms

LEVEL III: MIDDLE JUGULAR

At middle 1/3 of IJV Extends from:

extending from carotid bifurcation superiorly (surgical landmark) or

hyoid bone (clinical landmark) to junction of omohyoid ms with IJV (surgical landmark) or cricothyroid membrane (clinical landmark) inferiorly

L: Posterior border SCM M: Lateral border of sternohyoid

ms

LEVEL IV: LOWER JUGULAR

At lower 1/3 of IJV Extending from:

omohyoid ms superiorly to clavicle inferiorly

L:Posterior border of SCM A: Lateral border of

sternohyoid ms

LEVEL V: POSTERIOR TRIANGLE

Boundaries L: Anterior border of

trapezius ms M: Posterior border of SCM I: Clavicle

3 predominant lymphatic pathways SAN as it traverses posterior

triangle transverse cervical artery as

it courses lower 1/3 triangle Supraclavicular nodes

located above lateral 2/3 of clavicle

VI

LEVEL VI: ANTERIOR COMPARTMENT

At midline visceral neck structures Extends from

S: hyoid bone I: suprasternal notch

Boundaries L: Medial border of carotid sheath

Located within this compartment Perithyroidal lymph nodes Paratracheal lymph nodes Lymph nodes along RLN Precricoid (Delphian) lymph node

Pathways of spread from primary cancers originating in: thyroid gland apex of piriform sinus subglottic larynx cervical esophagus cervical trachea

THE END

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