Anatomy of the Neck

Anatomy of the Neck
Anterior triangle
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Midline of the neck
Sternocleidomastoid muscle
Lower border of the mandible
Subunits of ant. triangle
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Submandibular triangle
Submental triangle
Carotid triangle
Muscular triangle
Submandibular triangle
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Anterior & posterior bellies of digastric muscle
Lower border of the mandible
Submental triangle
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Anterior bellies of the digastric muscle
Hyoid bone
Posterior triangle
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Anterior border of the trapezius m.
SCM
Middle third of the clavicle
Subunits of post. Triangle
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Subclavian triangle
Occipital triangle
Fascial layer of the neck
The cervical fascia represents a condensation of
connective tissue that extends between
anatomic structures
Superficial Fascia
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Lies just below the dermis
Deep portions of this layer encase the platysma
muscle as well as the voluntary muscles of the
face & scalp
Deep cervical fascia
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Superficial layer
Middle layer
Deep layer
Superficial layer of deep cervical
fascia
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Begins from the vertebral spinous processes
and splits to enclose the trapezious
Again it splits to invest SCM as well as strap
muscle
Superior attachment : occipital protuberance ,
superior nuchal line & zigomatic arch
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Between parotid & submandibular glands the
two layer rejoin to form the stylomandibular
ligament
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Inferiorly the fascia split and attach to the
anterior and posterior surface of the sternum :
Suprasternal space of Burns
Middel layer of the deep cervical
fascia
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It encloses the thyroid gland , trachea ,
pharyngeal constrictor muscle & esophagus
It extends from the hyoid bone down to the
sternal attachments and is continuous with
fibrous pericardium
Deep layer of the deep cervical
Fascia
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Anterior to the vertebral bodies
Tips of transverse process
Vertebral spines posteriorly
From the skull base until the coccyx
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Prevertebral layer
Alar layer ( until first thoracic vertebra )
Danger space
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A potential space is created between the alar
and prevertebral fascias because it
communicates directly with the mediastinum
Prevertebral space
Between the prevertebral fascia and vertebral
body
Retropharyngeal space
Between alar and the visceral fascia
Tissue space of the neck
Between cervical fascia exist potential spaces
Because superficial and deep layers of the deep
cervical fascia fuse at the hyoid bone infection
in the spaces above the hyoid does not spread
directly to spaces below the hyoid
Communication along the entire length of the
neck occurs posteriorly along the
retropharyngeal and prevertebral spaces .
Submandibular space
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Between outer space of of mylohyoid muscle
and superficialstructure within submandibular
triangle
Along the posterior free edge of the mylohyoid
muscle it continuous with the sublingual space
It also communicate with submental and
contralateral submandibular space `
Intrapharyngeal space
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Inner surface of the superior constrictor muscle
and the pharyngeal mucosa
It also known as peritonsillar space
Parapharyngeal space
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Medial : superior constrictor m.
Lateral : pterygoid muscles and fascia of the
parotid gland
Inferior : Fascial attachment to the hyoid
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Posteromedially this space communicates with
the retropharyngeal space providing a route to
spread infection
Retropharyngeal space
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Entire length of the neck
Between visceral fascia and alar fascia
From the skull base down to the T1
Danger space
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Between alar fascia and prevertebral fascia
Retropharyngeal space→ danger space
→mediastinum
Prevertebral space
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Between prevertebral fascial and vertebral
column
From the skull base to the lower thoracic area
Artery of the neck
Common carotid artery
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Right side from brachiocephalic artery
Left side from aortic arch
It crosses by omohyoid muscle , , superior &
middle thyroid vein
Internal carotid artery
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it crosses by hypoglossal nerve , occipital
artery & posterior belly of digastric muscle
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Near skull base it crosses by glossopharyngeal
nerve ,stylohyoid , stylopharyngeous
,styloglossus muscle and styloid process
External carotid artery
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It crosses superficially to styloglossus and
stylopharyngeous muscle
Terminal branches passing behind the condylar
process
Superior thyroid artery
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At the level of greater horn hyoid bone
Superior part of thyroid gland , larynx and
SCM
Ascending pharyngeal artery
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At the level of sup. Thyroid artery posteriorly
Supply pharynx , palate , tonsil , middle ear
and meninges
Lingual artery
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Above the superior thyroid artery
Runs anterior and superior
Passes beneath the hyoglossus muscle to enter
the tongue
Facial artery
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On the anterior surface of carotid , deep to the
digastric muscle
Passes through the submandibular gland ,
crosses the inferior border of the mandible
Branches in the neck : ascending palatine
artery , tonsillar artery , branches of the
submandibular gland , submental artery
Occipital artery
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From posterior surface of the external carotid
artery the hypoglossal nerve hooks around it
Supply suboccipital region of the scalp , SCM ,
digastric and stylohyoid muscle
Posterior auricular artery
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Posteriorly at the level of the upper border of
digastric muscle
Passes between the mastoid and ear
Branches to the parotid gland , auricle and
scalp
Terminal branches
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Superficial temporal : toward the scalp
Maxillary artery : infratemporal fossa →
pterygopalatine fissure → pterygopalatine
fossa
Thyrocervical thrunk
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Arises from the first part of the subclavian artery just
anterior to the scalenus anrerior muscle
Transverse cervical branch → SCM , trapezius
Inferior thyroid artery : deep to the carotid sheath
Supply inferior portion of the thyroid , sup. & inf.
Parathyroid gland and a portion of larynx and trachea
Inter the thyroid at the level of cricoid
Vein of the neck
Internal jugular vein
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Sigmoid sinus → intrenal jugular vein →
subclavian vein
Major tributaries :inferior petrosal sinus
Common facial vein
lingual vein
superior thyroid vein
middle thyroid vein
External jugular vein
Posterior auricular vein + posterior branch
retromandibular vein
Deep to the platysma but superficial to the SCM
Terminate in the subclavian vein
At its midportion it joined by posterior external
jugular vein
Anterior jugular vein
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Confluence of the vein in the submandibular
region
Drain to the external jugular or subcalavian
vein
Nerve of the neck
Glossopharyngeal nerve
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Sensory , motor , parasympathic component
It has superior and inferior ganglion
Anterior to the internal and deep to the
external carotid artery
Pass between superior and middle constrictor
muscle
Innervate tonsil , pharynx and tongue
Tympanic nerve
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Arises from inferior ganglion
Tympanic canaliculus → middle ear (jacobson
nerve )
Sensory fiber to the middle ear , eustachian
tube and mastoid cavity
Lesser petrosal nerve
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Preganglionic parasympathetic fibers
Tympanic plexus → floor of middle cranial
fossa → foramen oval → infratemporal fossa
→ otic ganglion
In the otic ganglion it synapsis with
postganglionic fiber of parasympathic that
supply the parotid gland
Carotid branch
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Arises from IX nerve just below the skull base
Unit with carotid branch of vagus nerve and
carries sensory information back from the
carotid body and carotid sinus
Pharyngeal branch
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Reach to the pharyngeal plexus on the middle
constrictor muscle
Sensory innervation
Stylopharyngeus branch
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Only motor branch of the IX nerve
Supply stylopharyngeal muscle
Tonsilar branch
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Form a plexus with the lesser palatine nerve
Supply tonsil and soft palate
Lingual branch
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Taste and general sensation to the posterior 1/3
tongue
Vagus nerve
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Superior and inferior ganglion at the jugular
foramen
Sensory , motor and parasympathetic fibers
Superior ganglion branches
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Meningeal branch( posterior cranial fossa )
Auricular branch (pinna, EAC, TM )
Superior ganglion branch
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Pharyngeal branch ( pharynx and palate )
Superior laryngeal nerve
Right RLN : in front the subvlavian a.
Left RLN : in front the aortic arch
Accessory Nerve
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Cranial component : sensory
Join the vagus nerve
pharyngeal plexus
Spinal component : motor ( C2 – C4 )
lateral to IJV
emerge 1 cm above Erb point
Hypoglossal nerve
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Occipital bone → under posterior belly
digastric → looping around occipital a.→
across carotid arteries → deep to the
submandibular gland → on the surface of
hyoglossus muscle
Innervation : interinsic muscle of tongue ,
styloglossus , hyoglossus , genioglossus
Ansa cervicalis
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Motor innervation to the strap muscle
Upper branch : hypoglossus nerve
Lower branch : C2 , C3 from the cervical
plexus
Cervical sympathetic trunk
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Thoracic spinal cord → sympathetic cervical
ganglia →
Superior cervical ganglia ( at the level of the
C2 & C3 behind the carotid sheath
internal carotid nerve passes into carotid canal
→ internal carotid plexus
Cervical sympathic (cont )
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Middle cervical ganglia :
At the level of C6
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Inferior cervical ganglia :
in the root of the neck
Cervical plexus
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From C1 – C6
Motor & sensory nerve
Phrenic nerve (motor br : C3,C4,C5 )
Sensory br : lesser occipital nerve
greater auricular nerve
Anterior cutaneous nerve
supraclavicular nerve
Lymphatics of the neck
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Superficial group : submental
submandibular
superficial cervical
anterior cervical
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Deep group : pretracheal ,
paratracheal
perithyroid
retropharyngeal
The node of Rouviere refers
to the highest
retropharyngeal lymph node
which is adjacent to the
jugular foramen
Compartment of the neck
Level I
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Posterior belly of the digastric muscle
Body of the mandible
Hyoid bone
Submandibular nodes
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Preglandular
Postglandular
Prevascular
Postvascular
Intracapsular
Drainage
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Upper & lower lip , Cheek skin , nasal skin &
mucosa , medial canthus , anterior alveolus ,
anterior tonsillar pillar soft palate , 2/3 anterior
of the tongue , submandibular salivary gland
Drain into upper internal jugular nodes
Submental nodes
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2-8 nodes
Between anterior belly of digastric muscle
Mylohyoid platysma
Drain mentum , midportion of the lower lip ,
anterior alveous , anterior 1/3 of the tongue
Second drainage to ipsilat. & contralat.
preglandular or prevascular submandibular
nodes or IJV
Level II
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Base of the skull → carotid bifurcation or
hyoid bone
Posterior border of SCM → lateral border of
sternohyoid muscle
Level III
Carotid bifurcation to the omohyoid muscle or
cricothyroid notch
Level IV
Along the inferior 1/3 of the IVJ from the
omohyoid to the clavicle
Level V
From the anterior border of the trapezius m. to
the posterior border of SCM and the clavicle
inferiorly
Level VI
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Surrounded midline visceral structure
From the hyoid bone to the sternal notch
The lateral border is the carotid sheath
Consists of paratracheal node , perithyroid
nodes , precricoid ( Delphian ) nodes and
nodes along the RLN
Level VII
The upper mediastinal lymph node and inferior
to the suprasternal notch
Anterior nodal group
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Anterior jugular chain
Juxtavisceral chain : prelaryngeal
prethyroid
pretracheal
paratracheal
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Prelaryngeal : supraglottis
Prethyriod : infraglottic , thyroid isthmus ,
anteromedial thyroid lobe
Pretracheal node : from thyroid isthmus to the
innominate vein ,2-12 node ,thyroid gland and
trachea
Paratracheal : lateral aspect of thyroid &
parathyroid gland , postcricoid , trachea,
esophagus
Lateral group
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Superficial chain :
related to EJV
drain to transverse cervical
Deep group
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Spinal accessory chain
Transverse cervical chain
Internal jugular chain
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Spinal accessory chain : up to 20 nodes
Transverse cervical chain : 12 nodes
Internal jugular chain : 30 nodes
on left side : thoracic duct
on right side : right lymphatic duct
Sublingual nodes
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Along collecting trunk of the tongue &
sublingual gland
Drain anterior floor of the mouth & ventral
surface of the tongue
Connect to the submandibular group or upper
IJ chain
Parotid Nodes
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Extraglandular group : preauricular &
infraauricular nodes
Drain lateral and frontal aspects of the scalp,
anterior auricle , external auditory canal , skin
of the lateral face , buccal mucosa
Intraglandular nodes : drain the same side
Retropharyngeal node
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Between pharyngeal wall and prevertebral
fascia
Lateral group : 1-3 nodes at the level of C1
Medial group : to the level of the cricoid
Drain nasal cavity,sphenoid sinus, ethmoid
sinus,hard & soft palate, nasopharynx &
posterior pharyngeal wall
The retropharyngeal space
can be accessed by rotating
the pharynx medially and
opening the infected tissue
between the pharynx and
cervical spine
Occipital nodes
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Superficial group : 2-5 nodes
Between SCM & trapezius m. at apex of
posterior triangle , superficial to the splenius
m. & deep to investing fascia
Drain occipital scalp , posterior cervical skin
→ deep group → upper spinal accessory
Postauricular nodes
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1-4 nodes over fibrous insertion of SCM on the
mastoid tip
Drain posterior parietal scalp , skin of mastoid
and postauricular area → infraauricular parotid
LN
Cont.
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Deep group : 1-3 nodes deep to the splenius m.
along the course of the occipital artery
Drain the deep musculature of the neck in
occipital region→ INJ & spinal accessory
nodes
Thoracic duct
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Passes up through mediastinum → left root of
the neck → posterior to the carotid sheath &
medial to the anterior scalene m.
It empties through multiple branches into the
lowest portion of the IJV , the subclavian vein
or both
Main duct may extend as high as 5 cm above
the clavicle