The neck contains four longitudinal compartments - visceral, vertebral, and two vascular - that are organized by layers of cervical fascia. The superficial fascia lies just deep to the skin and contains cutaneous structures. Deep to it, the deep cervical fascia is organized into the investing, prevertebral, and pretracheal layers that surround and support the neck structures. Openings in the fascial layers determine the pathways infections may spread in the neck.

1. Of The Neck
FASCIA
By
Ali S. Mayali
Fig 1.0 – Compartments of the neck

2. Overview:
• 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 (fig 1.0):
• 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.

3. 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 the superficial
cervical fascia.

4. 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 (e.g. the external jugular vein)
• Superficial lymph nodes
• Fat
• Platysma muscle
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)

5. Deep Cervical Fascia
Deep to the superficial fascia. the
deep cervical fascia is organized into
several distinct layers. These include:
• an investing layer, which
surrounds all structures in the
neck.
• the prevertebral layer, which
surrounds the vertebral column
and the deep muscles associated
with the back.
• the pretracheal layer, which
encloses the viscera of the neck Fig 3.0 – Deep cervical fascia.

6. • Deep cervical fascia also condenses around the common 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

7. 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.

8. • 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

9. 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.

10. 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 – Pretracheal layer.

11. 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.

12. Fig 4.1 – Buccopharyngeal fascia.
Pretracheal layer

13. 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.

14. Prevertebral fascia
• The anterolateral portion of
prevertebral fascia surrounds the
brachial plexus and subclavian artery
as they leave the neck, forming
the axillary sheath.

15. 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
 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.

16. 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.

17. Clinical Relevance: Spread of infection!
Fig 6.0 – Spread of infection.

18. • 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 – retropharyngeal abscess.