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Clinical Anatomy: Neck
19 January 2022
09:56
The Neck is divided into two divisions:
1. Frontal plane
a. Passes through transverse process of cervical vertebra: anterior and posterior
b. Posteriorly: muscles lie on either side of cervical spinous process and a more superficial
layer formed by trapezius muscle.
c. Anteriorly and in the midline we find the respiratory and alimentary passages flanked by
vascular and nervous structures.
d. Centrally the neck is supported by cervical vertebra column from which the spinal nerves
emerge laterally.
2. Anterior division
a. Divided into medial triangle, lateral triangle, and SCM region.
Fascia's of the Neck:
1- Superficial Fascia
2- Superficial layer of the proper fascia
3- Deep layer of the proper fascia
4- Endocervical fascia
5- Prevertebral fascia
1- Superficial Fascia:
- Thin layer
- Lies between the skin and the proper fascia
- Encloses the platysma layer
2- Superficial layer of the proper fascia
- Surrounds the neck and it splits to enclose the sternocleidomastoid m., trapezius m., and
submandibular glands.
- Superiorly: attached to the lower border of the mandible
- Inferiorly: attached to the acromion, to anterior margins of the clavicle and the manubrium
sterni.
○ This layer creates the sheath of the submandibular gland, which divides into two layers,
these layers attach to the inferior border of the mandible. The submandibular gland is
separated from the parotid gland by thick fascial septum.
3- Deep layer of the proper fascia
- Inferiorly: attached to the posterior margins of upper border of the manubrium and clavicle.
Between the superficial layer and deep layer of the proper fascia {The suprasternal space exists and
the jugular venous arch goes through it}
^^These fascias are trapezium shaped
They are bounded on each side by omohyoid muscle.
It surrounds the infrahyoid muscles: sternohyoid, sternothyroid, thyroid, omohyoid.
4- Endocervical fascia
- Visceral
○ Surrounds all organs of the neck
- Parietal
○ Forms a sheath for the main vessels and nerves of the medial triangle.
○ Adjacent to posterior surface of the sheath of infrahyoid muscles.
○ Internal carotid arteries, internal jugular vein, vagus nerve, and the Ansa cervicalis.
5- Prevertebral fascia
- Covers the prevertebral muscles {the longus capitis and longus cervicis}
- Forms the floor of the lateral triangle and sheath for main vessels and nerves of the lateral
triangle {subclavian artery and vein and brachial plexus}.
- Surrounds the sympathetic trunk
Fat spaces of the Neck
1- Perivisceral space
2- Retro visceral space
3- Pretracheal space
4- Prevertebral space
In the 2nd fascia of the neck (the superficial layer of proper fascia):
- The sheath for the submandibular gland {this contains vessels nerves submandibular gland
lymphatic nodes and fat}
- The sheath for the sternocleidomastoid muscle (fat is between the posterior surface of
muscle and it’s sheath)
Between the 2nd and 3rd fascia(deep and superficial proper fascia):
- Suprasternal space {Contains jugular venous arch. Communicates with the blind retro
sternocleidomastoid sac.}
In the 4th fascia (endocervical)Between the visceral and parietal :
- Perivisceral space communicates with the fat of anterior mediastinum. Fat is located before
organs of the neck.
- Pretracheal fat space contains lymph nodes inferior thyroid veins and thyroidea ima artery.
Between the 4th and the 5th fascia (endocervical and prevertebral):
Retro visceral space fat communicates with posterior mediastinum
- Superiorly- reaches the base of skull.
- Inferiorly- base of diaphragm.
In the 5th fascia (prevertebral):
- Prevertebral fat space located between prevertebral fascia anteriorly and prevertebral
muscles (longus capitis longus crevices )
- Neurovascular space of the lateral triangle located in the sheath for vessels and plexus
communicates with the fat of the sheaths and vessels and nerves of axillary fossa.
Lateral triangle contains superficial fat space between 2nd and 5th fascia.
Medial triangle contains the neurovascular space of the medial triangle which is a sheath for main
vessels and nerves of the medial triangle. Contains fat and lymphatic nodes.
Lymph nodes of the neck:
1. submandibular nodes located in sheath of submandibular gland
2. Submental nodes located along submental triangle
3. Anterior cervical nodes along anterior jugular vein
4. lateral cervical nodes along external jugular vein
5. Deep cervical nodes along internal jugular vein
Suprahyoid Region
What are the boundaries?
- Superiorly- inferior margin of the mandible
- Inferiorly- line drawn through body of the hyoid bone on each side
- Laterally- anterior border of the sternocleidomastoid muscle.
What layers covers the suprahyoid region?
- Covered by the skin,
- Superficial fascia,
- Platysma,
- Superficial layer of proper fascia
Running across the region in this covering are:
- Cervical branch of the facial nerve
- Transverse cutaneous nerve
What triangles does this region contain?
Has two triangles:
1. Submental Triangle
○ Lies below the chin
○ Bounded laterally by the right and left anterior bellies of the digastric muscles
○ Inferiorly by the body of the hyoid bone
○ The floor of the triangle is formed by the mylohyoid muscle
○ Has submental lymph nodes and the beginning of the jugular vein.
2. Submandibular Triangle
○ Is bounded by inferior border of mandible
○ Anterior belly of digastric
○ Posterior belly of digastric
○ The floor of the triangle is formed by the mylohyoid and
 hyoglossus muscles {runs on the hyoglossus under mylohyoid muscles}.
○ Has submandibular salivary gland {The 2nd fascia creates the sheath of the
submandibular gland, which divides into two layers, these layers attach to the inferior
border of the mandible. The submandibular gland is separated from the parotid gland by
thick fascial septum.}
○ facial artery deep to it, facial vein + submandibular lymph nodes superficial to it.
○ It also has fat
Infrahyoid Region
What triangles does this region contain?
Has two triangles:
1. Omotracheal Triangle:
Boundaries:
○ Anteriorly: the midline of the neck
○ Superiorly: superior belly of the omohyoid
○ Inferiorly: anterior border of the sternocleidomastoid
○ The floor is formed by the sternohyoid and sternothyroid muscles, beneath this floor
and beneath the parietal and visceral layers of the endocervical fascia lies the organs of
the neck (which are- thyroid gland, the larynx, the trachea, the pharynx, the
oesophagus)
2. Carotid Triangle
Boundries:
○ Lies behind the hyoid bone
○ Superiorly: by the posterior belly of the digastric
○ Inferiorly: by the superior belly of the omohyoid
○ Posteriorly: by the anterior border of the sternocleidomastoid muscle.
What are the boundaries?
- Superiorly: line which is drawn through the body of the hyoid bone.
- Inferiorly: the suprasternal notch.
- Laterally: anterior borders of the sternocleidomastoid muscles.
What layers covers the infrahyoid region?
- Covered by skin,
- the subcutaneous tissue,
- the superficial fascia,
- the platysma,
- the superficial layer of the proper fascia,
- the deep layer of the proper fascia,
- the infrahyoid muscles,
- the parietal and visceral layers of the endocervical fascia.
Branches of transverse cutaneous nerves runs through here.
Triangles
1- Medial Triangle
Boundaries:
- Anteriorly- the median line of the neck
- Posteriorly- the anterior border of the sternocleidomastoid muscle
- Superiorly- the inferior border of the mandible
Further subdivided into smaller triangles: two above the hyoid bone, and two below the hyoid bone.
- Above the hyoid bone (Suprahyoid region) :Submental, Submandibular
- Below the hyoid bone (Infrahyoid region) : Carotid, Omotracheal.
2- Lateral Triangle
- Omotrapezius triangle (occipital)
○ The superficial fascia, the superficial layer of the proper fascia, the prevertebral fascia
- Supraclavicular triangle(carotid)
○ The superficial fascia, the superficial layer of the proper fascia, the prevertebral fascia,
and deep layer of the proper fascia
- The endocervical fascia is NOT present in the lateral triangle because the triangle is placed in
the lateral region.
3- Carotid Triangle
Boundries:
- Lies behind the hyoid bone
- Superiorly: by the posterior belly of the digastric
- Inferiorly: by the superior belly of the omohyoid
- Posteriorly: by the anterior border of the sternocleidomastoid muscle.
What layers cover the triangle?
- The skin
- The superficial fascia
- The platysma
- The superficial layer of the proper fascia
- The parietal layer of the endocervical fascia or carotid sheath and fifth fascia (prevertebral
fascia)
• Nerves
- Vagus
- Lingual External
- laryngeal Internal
- Spinal Accessory
- Hypoglossal
- Ansa cervicalos
- Sympathetic trunk
•Arteries
- Common carotid (with carotid body)
- Internal carotid (with carotid sinus)
- Superior thyroid
- Facial
- laryngeal
- Ascending pharyngeal
- Occipital
•Veins
- Internal Jugular vein
- Common facial
- Lingual Vein
- Superior Thyroid vein
- Middle thyroid vein
•structures
- Larynx
- Thyroid
4- Omotracheal Triangle
Boundaries:
- Anteriorly: the midline of the neck
- Superiorly: superior belly of the omohyoid
- Inferiorly: anterior border of the sternocleidomastoid
- The floor is formed by the sternohyoid and sternothyroid muscles, beneath this floor and
beneath the parietal and visceral layers of the endocervical fascia lies the organs of the neck
(which are- thyroid gland, the larynx, the trachea, the pharynx, the oesophagus)
5- Supraclavicular Triangle
Boundries:
- Superiorly: by the inferior belly of the omohyoid muscle
- Inferiorly: by clavicle
- Medially: by sternocleidomastoid muscle
Fascia's:
The superficial fascia, the superficial layer of the proper fascia, the prevertebral fascia, and deep
layer of the proper fascia
It passes:
- subclavian artery (posteriorly and superiorly to it) and
- subclavian vein (located anteriorly and inferiorly behind the clavicle) and
- brachial plexus(posteriorly to this) .
6- Submandibular Triangle
- Is bounded by inferior border of mandible
- Anterior belly of digastric
- Posterior belly of digastric
- The floor of the triangle is formed by the mylohyoid and
 hyoglossus muscles {runs on the hyoglossus under mylohyoid muscles}.
- Has submandibular salivary gland {The 2nd fascia creates the sheath of the submandibular
gland, which divides into two layers, these layers attach to the inferior border of the mandible.
The submandibular gland is separated from the parotid gland by thick fascial septum.}
- facial artery deep to it, facial vein + submandibular lymph nodes superficial to it.
- It also has fat
7- Pirogoff's Triangle (this is where the lingual artery may be found)
Boundaries:
- Superiorly: by hypoglossal nerve
- Inferiorly: by intermediate tendon of digastric muscle
- Anteriorly: by mylohyoid muscle
Sympathetic Trunk
- It is deep in the neck within the prevertebral fascia(the 5th)
- The cervical part (lies medial to vagus), extends upward to the base of the skull
- and below to the neck of the first rib,
- Where it becomes continuous with the thoracic part.
There exists:
- Superior cervical ganglion (lies at the level of 2nd and 3rd cervical vertebras)
- Middle cervical ganglion (lies at the level of the 6th cervical vertebra near the inferior thyroid
artery and the inferior cervical ganglion )
- Inferior cervical ganglion
 Fused with first thoracic ganglion to form cervico-thoracium (stellate ganglion)
 It lies in interval between transverse process of C7 and the neck of the first rib behind
the vertebral artery
Sternocleidomastoid region
Boundries:
- Superiorly: place of sternocleidomastoid muscle and reaches to the mastoid process
- Inferiorly: clavicle and manubrium sterni
- This muscle runs obliquely across the side of the neck and separates the lateral triangle from
the anterior medial triangle
- It covers carotid sheath
What covers the region?
- Skin
-
Subcutaneous tissue
Superficial fascia
Platysma
The superficial layer of proper fascia
The external jugular vein and nerves of cervical plexus lie between these fascia's.
Deep Intermuscular spaces
Located in the inferior part of the SCM region, behind the SCM muscle and lateral organs of the
neck.
1- Ante-scalene space
2- Interscalene space
3- Scalenovertebral triangle
1. ANTESCALENE SPACE
Boundaries
 Anteriorly and medially- STERNOHYOID and STERNOTHYROID
 Anteriorly and laterally - SCM
 Posteriorly - Scalenus anterior muscle
Space contain
Bulb of internal jugular vein, vagus nerve and common carotid artery
The subclavian vein joining with internal jugular vein is located in the inferior part of this
space.
2. INTERSCALENE SPACE
Boundaries
Located between the scalenus anterior and the scalenus Medius muscle
Passes
2nd part of the subclavian artery and brachial plexus
3. SCALENOVERTEBRAL TRIANGLE
Boundaries
 Laterally- Scalenus anterior muscle
 Medially - Longus coli muscle
Passes
The base of the this triangle forms cervical pleura above which PASSES THE FIRST PART
OF THE SUBCLAVIAN ARTERY
Subclavian artery are vertebral artery, thyrocervical trunk. Internal thoracic artery.