Superficial Structures of the Neck and Post Cervical Triangle
Muscles
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Superficial Fascia
Attached to the lower border of the Mandible and the fascia
covering the Pectoralis Major and Deltoid Muscles
Origin: deep fascia covering upper parts of P. major and Deltoid
muscle
Insertion: skin and subcutaneous fascia of lower part of the
face; body of the mandible and angle of the mouth
Nerve Supply: CN 7
Action:
o Depress the corners of the mouth
o Expression of fright or sadness
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Attached to the Mastoid Process of the temporal bone above,
and the Clavicle and Sternum inferiorly
This muscle separates the Anterior and Posterior Triangles of
the Neck
Nerve Supply: CN 11
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Superficial back muscle
Nerve Supply: CN 11
1. Mylohyoid
2. Geniohyoid
3. Stylohyoid
4. Digastric
Action:
o Elevate the Hyoid and Larynx
These muscles are found above the Hyoid bone
1. Sternohyoid
2. Omohyoid
3. Sternothyroid
4. Thyrohyoid
Action:
o Depress the Hyoid and Larynx
Also called as the Strap Muscles
They are located below the Hyoid Bone
The Sternohyoid, Omohyoid, and Sternothyroid are supplied by
the ansa cervicalis
Skeletal Support of the Neck
Hyoid Bone – located in the anterior part of the neck
o Not for skeletal support but for muscle attachment
7 Cervical Vertebrae
o C1 / Atlas
→ Atypical because it contains an anterior tubercle and
arch, no spinous process, instead it has a posterior
tubercle and an arch
o C2 / Axis
→ Atypical because at the body of the vertebra there is an
extended portion called odontoid process/ dens.it is
only articulating with your C1 forming the atlantoaxial
joint
o C7 / Cervical Prominens
→ Its elongated spinous process is palpable at the base
of the neck, the reason for the presence of this
structure is because it is transitioning to become a
thoracic vertebra
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Common to both typical and atypical vertebrae is the Transverse
Foramen (unique only to cervical vertebrae), the bifid spine,
rectangular body of vertebra with uncinate process and with
triangular vertebral foramen
Structure in the Superficial Fascia of the
Neck
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A layer of fatty connective tissue that lies between the dermis
of the skin and the investing layer of the deep cervical fascia.
It forms a thin layer that encloses the platysma and also
embedded in it are the cutaneous nerves, superficial veins, and
superficial lymph nodes.
A thin muscle in the superficial fascia of the neck
Most superficial muscle
Origin: deep fascia covering upper parts of P. major and Deltoid
muscle
Insertion: skin and subcutaneous fascia of lower part of the
face; body of the mandible and angle of the mouth
Nerve Supply: Facial nerve cervical branch
Action: draws the outer part of the lower lip downward and
backward
One of the landmarks in order to see the EJV is, it passes over
the SCM.
Not palpable unless congested it becomes more prominent
(clinical consideration in this case → Jugular Venous Pressure),
once it passes over the SCM, it will enter now the posterior
triangle and will drain to the subclavian vein
The only tributary of Subclavian Vein
Begins near the hyoid bone by the union of several superficial
veins from submandibular region
Lies anterior to the sternocleidomastoid
Terminate/drain either to the lower end of external jugular vein
or subclavian vein beneath sternocleidomastoid
Just above sternum the two anterior jugular veins communicate
by a transverse trunk called venous jugular arch - most often or
not, it is seen in the suprasternal space of burns
Lies along the external jugular vein superficial to the
sternocleidomastoid
Receive lymph vessels from occipital and mastoid lymph node
Drains into the Deep Cervical Lymph Node
Deep Cervical Fascia
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Composed of 3 layers and lies under cover of the platysma
o Investing/ Superficial Layer of Deep Fascia
o Pretracheal
o Prevertebral
It supports the muscles, blood vessels, and viscera of the neck
Forms sheaths for carotid vessels and for structures situated in
front of the vertebral column
The facial layers also determine the direction of spread of pus
or may limit the spread of infection.
Condensation: Carotid Sheath
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Superficial Layer of Deep Cervical Fascia
Thick layer that completely encircles the neck
Encloses the trapezius, sternocleidomastoid, posterior belly of
the digastric, parotid, and submandibular glands
• Forms the Stylomandibular Ligament
Attachments
o Superior:
→ Attached Hyoid Bone, lower border of mandible,
zygomatic arch, base of skull, mastoid process of
temporal bone, superior nuchal line of the occipital
bone and external occipital protuberance
o Inferior:
→ Acromion, clavicle, manubrium sterni
o Posterior:
→ Attached to spinous process and ligamentum nuchae.
From this attachment, this layer splits into 2 laminae to
enclose the trapezius
o Anterior:
→ To the trapezius muscle the 2 laminae come together
forming the roof of posterior cervical triangle, which
then splits again to enclose sternocleidomastoid
• Over posterior cervical triangle its deeps surface gives off an
investment for omohyoid which holds the muscle to the clavicle
• Beneath sternocleidomastoid its deep lamina contributes to
connective tissue forming the Carotid Sheath
• The superficial and deep fascia forms Suprasternal Space Of
Burns near the clavicle
o The space contains jugular venous arch and lymph node
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Stretches across the front of the neck immediately behind the
infrahyoid muscles and continuous on both sides with the deep
surface of the investing layer beneath the SCM
• Also wraps the infrahyoid muscles in front
Attachments
o Superior Attachment:
→ Oblique line of Thyroid Cartilage
→ Cricoid Cartilage
o Inferior Attachment:
→ Posterior Aspect of the Sternum – this blend with the
Fibrous Pericardium and with Adventitia of the Great
Vessels as they enter or leave the Pericardial Sac
• Attached to the Cricoid Cartilage and extends from Hyoid Bone
to the Fibrous Pericardium of Superior Mediastinum
• This communication represents a potential pathway for the
spread of infection to the heart, causing it to be labeled as a
Dangerous Layer
• Part of Pretracheal Layer actually covers the thyroid gland and
you call that as the False Capsule, this capsule attaches
posteriorly to cricoid cartilage.
• This attachment is called Ligament of Berry, so when you
swallow the thyroid gland also moves. That’s why if there’s an
enlargement of the thyroid gland, you ask the patient to swallow
and you palpate the thyroid gland.
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Lies anterior to bodies of the cervical vertebrae and
prevertebral muscles.
Covers the Subclavian Vessels and the Roots of the Brachial
Plexus.
Covers the Prevertebral Muscles
o Longus Capitis
o Longus Cervicis
Forms the floor of the Posterior Triangle of the Neck (particularly
the Occipital Triangle)
Covers the Lateral Vertebral Muscle
o Scalene Muscles
o Levator Scapulae
o Splenis Capitis
o Semispinalis Capitis
These muscles form the FLOOR of Posterior Triangle, therefore
the floor of the Posterior Triangle is covered by Prevertebral
Fascia
Superiorly attached to the base of the skull
Posteriorly attached to Ligamentum Conchae
o Inferiorly, it enters the thorax and blends with anterior
longitudinal ligament of the vertebral column
o It also has a thoracic portion forming now the Sibson’s
Fascia and it also further deepens into the thorax and forms
the Endothoracic Fascia
Interval between the pharynx and prevertebral fascia
Considered as the “Danger Space of the Neck”
o Space represents a possible route for spread of infection or
abscess from the head to the mediastinum
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Tubular condensation of the Prevertebral, Pretracheal, and the
Investing Layers of the Deep Fascia that surround the Common
and Internal Carotid Arteries, the Internal Jugular Vein, the
Vagus Nerve, and the Deep Cervical Lymph Nodes.
• Extends from the base of the skull to the roof of the neck
• Superficially: blends with the Superficial Layer of Cervical Fascia
deep to the SCM and the adjacent part of Pretracheal Layer
• Posteriorly: blends with Prevertebral Fascia
Contents
o Medially: Common and Internal Carotid Artery
o Laterally: Internal Jugular Vein
o Posteriorly: Vagus Nerve
o Deep Cervical Lymph Nodes accompanying the IJV
o The superior root of the Ansa Cervicalis – sometimes
embedded in the Carotid Sheaths
• The cervical part of the sympathetic trunk is embedded in the
prevertebral fascia immediately posterior to the sheath.
• The Ansa Cervicalis/Ansa Hypoglossi – is a loop of nerve that
is part of the Cervical Plexus (C1 to C3), innervates Infrahyoid
Muscles
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Posterior Triangle of the Neck
Also forms an investment of thyroid gland, forming its False
Capsule: this encapsulation of thyroid gland makes it move
during swallowing, it is also attached posteriorly to a suspensory
ligament: Ligament of Berry
Also encloses Parathyroid gland and Infrahyoid muscles
An extension of the Prevertebral Fascia carried to the Axilla by
the Subclavian Artery and the Brachial Plexus as they emerged
in the interval between the Scaleni Anterior and Medius
Enclosed the Axillary Vessels and the cords of the Brachial
Plexus at the Axilla
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Anterior: posterior border of the Sternocleidomastoid
Posterior: anterior border of the Trapezius
Inferior: middle third of the Clavicle
Roof: Superficial layer of the Deep Cervical Fascia
Floor: Prevertebral Fascia
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Scalene Anterior
Scalene Medius
Scalene Posterior
Splenius Capitis
Semispinalis Capitis
Levator Scapula
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Occipital Triangle
Subclavian/Omoclavicular Triangle
The Posterior Triangle is crossed by the inferior belly of the
omohyoid dividing it into Occipital and Supraclavicular or
Subclavian Triangles.
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Boundaries
o Anterior: Sternocleidomastoid
o Posterior: Trapezius
o Inferior: Inferior Belly of the Omohyoid
o Floor: formed from above downward by the Splenius Capitis,
Levator Scapulae, and Scalene Medius and Posterior
Called occipital triangle because its apex contains a portion of
occipital bone and possibly because the occipital artery appears
in the superior part of this triangle
The mocst important nerve crossing the occipital triangle is the
accessory nerve
Contents
o Occipital Bone
o Occipital Artery
o Accessory Nerve
o Cutaneous branches of the Cervical Plexus
o Upper part of Brachial Plexus
o Transverse Cervical Vessels and Lymph Nodes
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Smaller division
Indicated on the surface of the neck by the supraclavicular
fossa
The external jugular vein crosses the supraclavicular triangles
superficially and the 3rd part of subclavian artery deep in it
Boundaries:
o Anterior: sternocleidomastoid
o Superior: inferior belly of the omohyoid
o Inferior clavicle
o Floor: formed by the posterior border of the
sternocleidomastoid
Contents:
o EJV (terminal part)
o Suprascapular artery and vein
o 3rd part of Subclavian artery and vein
o Transverse cervical artery and vein
o Supraclavicular nerves and Subclavian nerve and lymph
nodes
Supplies the SCM and Trapezius
Passes postero-inferiorly in the Posterior Triangle on the Levator
Scapulae accompanied by the Anterior Rami of C3 and C4
Spinal Nerves and passes deep to the Anterior Border of the
Trapezius
Superficial to the Levator Scapulae
Divides the Posterior Triangle into nearly equal Superior and
Inferior Parts
Enters the Posterior Triangle at/or inferior to the junction of
Superior and Middle 3rd of the posterior border of the SCM
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Branches from the Roots
o Dorsal Scapular Nerve (C5)
→ Pierces the Scalene Medius
→ Supplies the Levator Scapulae and the Rhomboid
Muscles
o Long Thoracic Nerve (C5-C7)
→ Descends behind the Brachial Plexus and Subclavian
Vessels, crosses the outer border of the 1st rib and
enters the axilla
→ Supplies the Serratus Anterior
Branches from the Upper Trunk
o Suprascapular Nerve
→ Passes laterally downward, accompanied by the
suprascapular vessels
→ Enters the supraspinous fossa of the scapula through
the suprascapular notch
→ Supplies the supraspinatus and infraspinatus
o Nerve to Subclavius
→ Passes downward anterior to the brachial plexus and
the 3rd part of subclavian artery
→ Leaves the posterior triangle by descending posterior
to the clavicle and in front of the subclavian vein
→ Supplies the subclavius
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Between the Anterior and Middle Scalene
Formed by Ventral Primary Rami of C5 to T1 Spinal Nerves in 4
stages: roots, trunks, divisions and cords
Roots emerges at the Posterior Triangle between the Scalene
Anterior and Scalene Medius
Its Supraclavicular Part is located in the Posterior Triangle,
immediately anterior to the Scalene Medius, its Infraclavicular
Part is at the Axilla
Anterior Rami of C1 to C4 make up the roots of the Cervical
Plexus
Can be seen superficial to the Levator Scapulae and the Middle
Scalene
It gives off Sensory and Motor Branches
Covered in front by the Prevertebral Layer of Deep Cervical
Fascia and is related to the Internal Jugular Vein within the
Carotid Sheath.
Anastomoses with the accessory nerve, hypoglossal nerve, and
the sympathetic trunk.
Innervates the skin and the muscles of the head, shoulder and
some of the neck muscles.
Back of Neck and Scalp
o Cutaneous Nerves
→ Posterior Rami of Cervical Nerves 2 to 5
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Greater Occipital Nerve (C2) – supplies the
posterior aspect of the skull
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Front and Sides of the Neck
o Cutaneous Nerves
→ Anterior Rami of Cervical Nerves 2 to 4 through
branches of the Cervical Plexus
→ These nerves emerge from the posterior border of the
SCM
Nerve
Lesser Occipital Nerve (C2)
Greater Auricular Nerve (C2
and C3)
Transverse Cutaneous Nerve
(C2 and C3)
Supraclavicular Nerve (C3
and C4)
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Cutaneous Innervation
Lateral part of occipital region
Medial surface of auricle
Angle of the mandible/parotid
Auricle
Anterior and Lateral Surfaces
of the neck
Chest wall, shoulder
Hooks around the accessory nerve and ascends along the posterior
border of the sternocleidomastoid muscle to supply the skin over
the lateral part of the occipital region and the medial surface of the
auricle
Ascends across the sternocleidomastoid muscle and divides into
branches that supply the skin over the angle of the mandible, the
parotid gland, and on both surfaces of the auricle
1st Part
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Emerges from behind the middle of the posterior border of the
sternocleidomastoid muscle. It passes forward across that muscle
and divides into branches that supply the skin on the anterior and
lateral surfaces of the neck, from the body of the mandible to the
sternum
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Emerge from beneath the posterior border of the
sternocleidomastoid muscle and descend across the side of the
neck. They pass onto the chest wall and shoulder region, down to
the level of the 2nd rib.
• Medial Supraclavicular Nerve – supplies the skin as far as the
median plane
• Intermediate Supraclavicular Nerve – supplies skin of chest
wall
• Lateral Supraclavicular Nerve – supplies skin over the shoulder,
upper half of the deltoid, and posterior aspect of shoulder
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Derived from C3 to C5
Seen anterior to the Anterior Scalene and enters the
mediastinum
Motor supply of the Diaphragm
Sensory to the Pericardium, Mediastinal Pleura, and Central
Portion of the Diaphragm
Curves around the lateral border of scalene anterior
Descends obliquely across its anterior surface deep to
transverse cervical and suprascapular artery
Enters the thorax crossing the origin of internal thoracic artery,
between subclavian artery and vein
Right Subclavian Artery arises from the Brachiocephalic Artery
Left Subclavian Artery arises from the Arch of Aorta
Found in the space between the Anterior and Middle Scalene
Muscles
The Anterior Scalene will divide the Subclavian Artery into 3
parts:
o Medial – 1st Part
o Posterior – 2nd Part
o Lateral – 3rd Part
Becomes the Axillary Artery at the border of the 1st Rib
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Branch
Vertebral Artery
Thyrocervical Trunk
2nd Part
Internal Thoracic Artery
Costocervical Trunk
3rd Part
Usually has no branches
Gives Rise To
Transverse Cervical
Artery
Suprascapular Artery
Inferior Thyroid Artery
Superior Intercostal
Artery
Deep Cervical Artery
Right Common Carotid Artery arises from the Brachiocephalic
Trunk
Left Common Carotid Artery arises from the Arch of Aorta
The Common Carotid Artery ascends in the neck and at the
upper border of the Thyroid Cartilage, it will bifurcate into the
Internal Carotid Artery and External Carotid Artery
Internal Carotid Artery
o Has no branches in the neck
o Carotid Sinus – dilated proximal part
External Carotid Artery
o Main supply of the neck
o Branches:
→ Superior Thyroid Artery
→ Ascending Pharyngeal Artery
→ Lingual Artery
→ Facial Artery
→ Occipital Artery
→ Posterior Auricular Artery
→ Superficial Temporal Artery
→ Maxillary Artery
o Within the Parotid Gland, it will bifurcate into 2 of its
terminal branches:
→ Superficial Temporal Artery
→ Internal Maxillary Artery
Union of the:
o Posterior division of the Retromandibular Vein
o Posterior Auricular Vein
Found deep to the Platysma
It will drain to the Subclavian Vein
Joined to the opposite vein by the Jugular Arch above the
Sternum
Drains to the External Jugular Vein
Found close to the midline
Continuation of the Sigmoid Sinus
Joins the Subclavian Vein behind the medial end of the Clavicle
to form the Brachiocephalic Vein
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Continuation of the Axillary Vein after passing the lateral border
of the 1st Rib
Posterior to the Anterior Scalene
Clinical Correlation
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Right Internal Jugular Vein is preferred because it is larger and
straighter
Lateral to the Common Carotid Artery aiming at the apex of the
triangle between the Sternal and Clavicular heads of the SCM
Directed towards the ipsilateral nipple
For diagnostic or therapeutic purpose
Ideal Position of the Tip: junction between the Superior Vena
Cava and Right Atrium
Complication
o Check for Pneumothorax
Atherosclerotic thickening of the intima of the Internal Carotid
Artery may obstruct blood flow going to the brain
Depending on the degree of occlusion, this plaque may cause
transient symptoms or may lead to stroke
The procedure to get rid of this plaque is called Carotid
Endarterectomy
In this procedure, the plaque, together with the intima, is
stripped off from the vessel
Minimally invasive
A catheter is placed in the region of the plaque and a balloon is
inflated to compress the plaque
After that, a stent is placed in that region to maintain the
patency of the vessel
Muscles of the Floor of Posterior Triangle
o Insertion: scalene tubercle on inner part of the 1st rib
o Nerve Supply: Lower cervical spinal nerves (Anterior
rami of C5,C6)
o Action: Elevates 1st rib, slightly rotates the neck
2. Scalene Medius
o Origin: posterior tubercle of transverse process of all
cervical vertebrae
o Insertion: Superior border of posterior part of 1st rib
o Nerve Supply: Lower cervical spinal nerves
o Action: Elevates 1st rib, flexes and rotates cervical
portion of vertebral column to opposite side
3. Scalene Posterior
o Origin: posterior tubercle of transverse process of C4-6
vertebrae
o Insertion: external border of 2nd rib
o Nerve Supply: Lower 3 cervical spinal nerves
o Action: elevates 2nd rib, flexes cervical portion of
vertebral column
Note: All the Scalene Muscles originate from the Cervical
Vertebrae, they are part of the muscles for Forced
Respiration
4. Levator Scapulae
o Origin: transverse process of upper 4 cervical triangle
o Insertion: medial border of scapulae up to its superior
angle
o Nerve Supply: 3rd and 4th cervical spinal nerves of
cervical plexus or dorsal scapular nerves (C5 spinal
nerve)
o Action: Elevates scapula
5. Splenius Capitis
o Origin: lower half of ligamentum nuchae and spinous
process of 7th cervical and upper 3 or 4 thoracic
vertebrae
o Insertion: occipital bone below lateral part of superior
nuchal line and into mastoid process
o Nerve Supply: Lower cervical spinal nerves
o Action: draws head and neck backward laterally,
rotates the head and neck, turning the face to same
side. When acting bilaterally, it extends the head and
neck
Note: the direction of its fibers is toward the Mastoid
Process because it is inserted there and also to the
Occipital Bone above, giving now a V-Shape
Configuration.
6. Semispinalis capitis
o Origin: transverse process of T1-T6 vertebrae
o Insertion: medial half of the area between the superior
and inferior nuchal line on the occipital bone
o Nerve Supply: dorsal rami of cervical spinal nerves
o Action: extends the head when acting bilaterally,
rotate the head towards the opposite side when acting
unilaterally
1. Scalene Anterior
o Origin: anterior tubercle of the transverse process of
3rd to 6th cervical vertebrae
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