The neck contains four compartments separated by fascial layers: visceral, vertebral, and two vascular compartments. The superficial cervical fascia lies just deep to the skin and contains cutaneous nerves, veins, lymph nodes, and the platysma muscle. Deeper is the deep cervical fascia, organized into layers including the investing layer surrounding the neck, pretracheal layer enclosing structures like the thyroid, and prevertebral layer surrounding the vertebral column. These fascial layers are important as they determine the spread of infection, which can extend between layers into dangerous spaces like the retropharyngeal space and mediastinum.
5. NECK
• The neck is a tube providing continuity from the head to
the trunk. It extends anteriorly from the lower border of
the mandible to the upper surface of the manubrium of
the sternum and posteriorly from the superior nuchal line
on the occipital bone of the skull to the intervertebral
disc between the CVII and TI vertebrae
• four compartments provide longitudinal organization
• The visceral compartment is anterior parts of the
digestive and respiratory several endocrine glands.
• The vertebral compartment is posterior and
contains the cervical vertebrae, spinal cord,
cervical nerves, and muscles associated with
the vertebral column.
• The two vascular compartments, one on each side,
are lateral and contain the major blood vessels and
the vagus nerve [X].
All these compartments are contained within unique layers
of cervical fascia.
6. CUTANEOUS NERVES
Skin over the
Trapezius and back of the scalp
supplied by posterior rami of
cervical nerves 2-5.
7. Superficial fascia
• Lies immediately next to the skin.
• Consists of fats and
connective tissue.
• Contains cutaneous nerves,
superficial veins, superficial
lymph nodes and platysma.
Fig 2.0 – The platysma muscle, located within thesuperficial
cervical fascia.
8. Superficial Cervical Fascia
The superficial cervical fascia lies between the dermis and the
deep cervical fascia. It contains various structures:
• Neurovascular supply to the skin
• Superficial veins the external jugular vein
• Superficial lymph nodes
• Fat
• Platysma muscle : thin but clinically imp, embebded in
superficial fasica
In obese individuals, extra fat is deposited in the superficial fascia,
creating the ‘double chin’.
The platysma muscle is situated on the anterior aspect of the
neck. It has two heads, which originate from the fascia of the
pectoralis major and deltoid. Fibers from the two heads cross the
clavicle, and meet in the midline, fusing with the muscles of the
face.
• Develops from the 2nd pharyngeal arch and is supplied by
branches of the facial nerve (CN VII).
• Function: depresses the mandible
Superficial fascia (details)
13. Deep Cervical Fascia
• Pretracheal layer : thin layer that is
attached to the laryngeal cartilages.
Surrounding the thyroid and parathyroid
glands , forming a sheath , enclosing infrahyoid
muscles
Deep to the superficial fascia. the
deep cervical fascia is organized into
several distinct layers. These include:
• an investing layer, Thick
layer encircling the neck and
enclosing trapezius and SCM
• the prevertebral layer, thick layer passing like a septum across the neck behind the
Pharynx and Esophagus , in front of the prevertebral muscles and vertebral column
Fig 3.0 – Deep cervicalfascia.
14. • Deep cervical fascia also condenses around
the common carotid and internal carotid
arteries, internal jugular veins and vagus
nerves to form the carotid sheath.
The deep cervical fascia has several functions,
including:
• Support
• Viscera (e.g. thyroid gland)
• Muscles, Vessels and deep Lymph Nodes
• Limit the spread of abscesses that result from
infections
• Slipperiness that allows structures in
the neck to move and pass over one
another without difficulty
• Swallowing
• Turning the head and neck
Deep Cervical Fascia
15.
16. Investing Layer
The investing layer completely
surrounds the neck. Attachments:
Superior: attaches to the external
occipital protuberance and the
superior nuchal line.
Anterior: attaches to the hyoid
bone.
Inferior: attaches to the spine and
acromion of the scapula, the clavicle,
and the manubrium of the sternum.
Posterior: attaches along
the ligamentum nuchae. Fig 3.0 – Investing layer.
17. • Where it meets the trapezius and
sternocleidomastoid muscles, it
splits into two, completely
surrounding them.
• The investing fascia can be thought
of as a tube; with superior, inferior,
anterior and posterior attachments
• Component of the investing layer:
• 2 muscles: SCM and trapezius
• 2 salivary glands: Parotid and
submandibular glands
• 2 spaces: suprasternal and
supraclavicular spaces
Investing Layer
18. Clinical Relevance
Because of the presence of
thick tough parotid-masseteric
fascia which covers the parotid
gland swellings of the parotid
gland (mumps, parotitis) are
very painful.
Picture 1.0 – Parotitis.
19. Pretracheal layer
The pretracheal layer of fascia is
situated anteriorly in the neck. It
spans between the hyoid bone
and the thorax, where it fuses
with the pericardium.
It can be anatomically divided
into two parts:
• Visceral – encloses the thyroid
gland, trachea and esophagus.
• Muscular – encloses the
infrahyoid muscles.
Fig 4.0 – Pretracheallayer.
20. Pretracheal layer
• Posterior to the pharynx. the
pretracheal layer is referred to as the
buccopharyngeal fascia and
separates the pharynx from the
prevertebral layer.
•The retropharyngeal space it is a potential
space between the visceral part of the
pretracheal layer anteriorly and the
prevertebral layer posteriorly.
• it is the largest, most important interfascial
space in the neck
- because it is the major route for
spread
of infection from the neck to the
thorax.
22. Prevertebral fascia
The prevertebral layer is a
cylindrical layer of fascia that
surrounds the vertebral column
and the muscles associated with
it.
The prevertebral fascia is attached
posteriorly along the length of the
ligamentum nuchae, superiorly to
the base of the skull and inferiorly
to anterior longitudinal ligament
of the vertebral column Fig 5.0 – Prevertebral layer.
23. Prevertebral fascia
• The anterolateral portion of
prevertebral fascia surrounds the
brachial plexus and subclavian artery
as they leave the neck, forming the
axillary sheath.
24. Other component of the deep cervical
fascia:
• Carotid sheath: a condensation of the deep cervical fascia. Carotid sheath
makes a free communication with the mediastinum of the thorax making a
potential pathway for spread of infection and blood to the mediastinum.
Contains:
The common carotid artery and internal carotid artery
Internal jugular vein
The vagus nerve (CN X)
• Visceral Fascia: encloses the pharynx and esophagus, larynx and
trachea.
• Potential Fascial Spaces: Alar and retropharyngeal spaces.
25. Clinical Relevance: Spread of infection!
The deep fascial layers determine the direction in which abscesses in
the neck may spread. If an infection occurs:
• Between the Investing layer and the muscular part of the pretracheal
surrounding the infrahyoid muscles, it will not spread beyond the
manubrium.
• Between the Investing and visceral Pretracheal layers, it can spread into
the thoracic cavity anterior to the pericardium.
27. • Pus from an abscess lying behind the
Prevertebral layer of deep cervical fascia
may extend laterally in the neck.
May perforate the fascial layer and
enter the retropharyngeal space.
This will produce a bulge
(retropharyngeal abscess) in the
pharynx, resulting in dysphasia
(difficulty swallowing) and
dysphonia (difficulty speaking)
Clinical Relevance: Spread of infection!
Fig 6.0 – retropharyngealabscess.