anatomy of neck

1. General anatomy and
Lymphatic drainage of Neck
Dr. Krishna Koirala
MBBS, MS (ENT-HNS)
2020/02/10

2. • Neck : Area between the lower border of mandible
above and suprasternal notch and clavicle below
• Complex region :
− Passageway for communication between head and
rest of the body
• Contains vital structures : larynx, trachea, esophagus,
great vessels, cranial nerves, sympathetic trunk,
spinal cord

3. Fascia and fascial spaces of Neck
• Importance
− Localization and spread of neck space infections
is dependent upon the facial planes
− Dissection is easier, better controlled and more
bloodless if it proceeds along the fascial planes

4. • Skin
– Contains constant natural lines of cleavage
horizontally
– Incision along the cleavage line gives narrow scar
• Superficial fascia
− Thin layer that encloses platysma, cutaneous
nerves, superficial veins, superficial lymph nodes
• Deep fascia
– Investing layer ,Visceral layer , Internal layer

5. • Investing layer
• Superiorly attached to the nuchal line, mastoid
process and mandible
• Inferiorly attached to the spine of C7, clavicle and
manubrium
• Splits to surround trapezius and sternomastoid
• Forms sheaths to parotid and submandibular gland
, carotid sheath and cranial nerves

6. Superior nuchal line of occipital
bone (a)
Spinous processes of cervical
vertebrae and nuchal
ligament(b)
Mastoid processes of temporal
bones(c)
Zygomatic arches(d)
Inferior border of mandible(e)
Hyoid bone(f)
Manubrium(g)
Clavicles(h)
Acromion(i)
Folds to form the stylomandibular
ligament(j)

7. • Middle layer ( Two subdivisions)
− Muscular division surrounds the infrahyoid strap
muscles
− Visceral division envelops the pharynx, larynx,
esophagus, trachea, and thyroid gland
• Deep Layer (Prevertebral fascia)
− Surrounds deep muscles of neck
− Cervical sympathetic trunk lies superficial to fascia
− Cervical plexus, phrenic nerve and brachial plexus
lie deep to fascia

10. Deep Neck Spaces
• Described in relation to the hyoid bone
• Those traverse the entire length of the neck
– Retropharyngeal space, Danger space, Prevertebral
space, Visceral vascular space ( Carotid sheath)
• Suprahyoid
− Submandibular space, Parapharyngeal space,
Peritonsillar , Masticator, Parotid, Temporal space
• Infrahyoid
– Anterior visceral space

11. Parapharyngeal Space
• Boundaries
− Base and superior limit - Skull Base
− Apex – Lesser cornu of hyoid
− Lateral – Ascending ramus of mandible, Medial Pterygoid,
Parotid fascia and gland
− Medial – Buccopharyngeal fascia
− Anterior - Pterygomandibular raphe
− Posterior - Prevertebral fascia
− Inferior - Fascia lateral to angle of mandible

13. Parapharyngeal Space

14. • Subdivisions (Compartments) and contents
− Prestyloid compartment :
−Retromandibular portion of deep lobe of the
parotid gland, adipose tissue, lymph nodes
associated with the parotid gland
− Poststyloid compartment :
−Internal carotid artery, internal jugular vein, CNS
IX- XII, sympathetic chain, lymph nodes

15. Retropharyngeal space
• Immediately posterior to the nasopharynx,
oropharynx, hypopharynx, larynx, and trachea
• Boundaries
– Buccopharyngeal fascia anteriorly
– Alar fascia posteriorly
– Carotid sheath and parapharyngeal space laterally
– Base of the skull superiorly
– Inferiorly to the mediastinum at the level of the
tracheal bifurcation

16. • Divided into two lateral compartments (space of
Gillette) by a fibrous raphe
• Each lateral compartment contains retropharyngeal
nodes which usually disappear after 4-5 years of age
• Communicates with the parapharyngeal space and
the posterior mediastinum leading to spread of
infection to these areas

17. • Danger space
− Formed anteriorly by the alar fascia and
posteriorly by the prevertebral fascia
− Extends down the mediastinum to the level of the
diaphragm
• Prevertebral space
– Bounded anteriorly by the prevertebral fascia and
posteriorly by the longus coli muscles of the spine
– Continues to the insertion of the psoas muscles

19. Submandibular space
• Boundaries
– Inferior : superficial layer of the deep cervical
fascia extending from hyoid to the mandible
– Lateral : body of the mandible
– Superior : mucosa of the floor of mouth

20. Subdivisions
• Divided by the myelohyoid muscle into
• Sublingual space ( Supramyelohyoid)
– Contains sublingual gland, hypoglossal nerve and
Wharton’s duct
– Continuous with the submaxillary space via the
posterior margin of the myelohyoid muscle
• Submaxillary space ( Inframyelohyoid)

23. Triangles of Neck

24. Anterior triangle
• Anteriorly - midline of neck
• Posteriorly - anterior border of Sternocleidomastoid
• Superiorly - lower border of mandible
• Floor - myelohyoid, hyoglossus
• Subdivided by bellies of digastric and omohyoid
muscles into submental, submandibular, carotid,
muscular triangles

26. • Chief contents of anterior triangle
− Common carotid , external and internal carotid
arteries
− Internal jugular vein
− Vagus and recurrent laryngeal nerves
− Submandibular gland
− Lymphatic tissue

27. Posterior Triangle
• Anteriorly by posterior border of SCM
• Posteriorly by trapezius
• Inferiorly - middle 3rd of clavicle
• Floor - deep layer of deep cervical fascia
• Roof - superficial layer of deep cervical fascia
• Subdivided to occipital and subclavian by
posterior belly of omohyoid muscle

29. • Contents of posterior triangle
−Subclavian artery
−Brachial plexus
−Spinal accessory nerve
−Posterior cervical nodes

30. Lymph node Levels of Neck
( The Memorial Sloan Kettering
Hospital –New York Classification )

31. Level I ( Submental / Submandibular)
– Below myelohyoid muscle and above the lower
margin of the hyoid bone
– Anterior to the posterior border of the submandibular
glands
– Level I a : Submental ( between the anterior bellies
of the digastric muscle)
– Level I b : Submandibular (posterolateral to the
anterior belly of digastric)

33. Level II ( Upper jugular / upper deep cervical)
• Base of skull to lower margin of hyoid bone
• Anterior to the posterior border of sternomastoid and
posterior to the posterior border of submandibular
glands
• Level II a : Anterior, lateral or medial to the internal
jugular vein
• Level II b : Posterior to the internal jugular vein with
a fat plane separating the nodes and the vein

34. Level III (Middle jugular/ middle deep
cervical nodes)
• Lower margin of hyoid to lower margin of
cricoid cartilage
• Anterior to the posterior border of SCM and
lateral to the medial margin of the CCA / ICA

35. Level IV ( Lower jugular / lower deep
cervical nodes)
• Lower margin of cricoid cartilage to level of the
clavicle
• Anterior and medial to an oblique line drawn through
the posterior edge of the sternocleidomastoid muscle
and the posterolateral edge of the anterior scalene
muscle and lateral to the medial margin of the CCA

36. • Level V (Posterior triangle nodes )
– Level V a : superior half, posterior to levels II and III
– Level V b : inferior half, posterior to level IV
• Level VI (prelaryngeal /pretracheal /Delphian node)
− From inferior margin of hyoid to manubrium
− In front of levels III and IV
• Level VII (superior mediastinal )
– Between CCAs, below top of manubrium