Fascial Layers and Anatomical compartments of the neck

What is an anatomical space

continuous area or expanse within the body which is free, available or unoccupied

Give an example of an anatomical space

-bony spaces or fossae

What are the 2 categories of anatomical spaces

true anatomical spaces

potential anatomical spaces

true anatomical spaces

demonstrable and occur normally

potential anatomical spaces

• do not exist normally

• creates as a result off pathologies creating spaces or openings that didn’t exist before

What is the most abundant tissue type

fascia

What is fascia

the body’s connective tissue matrix

all-encompassing and interwoven system of fibrous connective tissue found throughout the body

Where in the body does the fascia span

head to toe

inside to out

outside to in

Why is fascia important?

-provides a framework that organises, supports and protects muscle groups, organs and tissue units of the body

Functions of the neck

joins the head to the rest of the body

site for controlled passage of food and gases between cavities of the head, thorax and abdomen

In terms of mobility why is the neck relevant

The neck has a lot of mobility

Why is the neck divided into fascial compartments?

-allow for ease of movement during breathing and swallowing

-formation of natural planes (pre existing layers) for tissue packing (how structures are arranged and held in place)

-determination of spread of infection

What are the generic tissue layers enveloping any body surface from superficial to deep

-skin

-superficial fascia

-deep fascia

-muscles

-bones

-organs

function of superficial fascia

binds skin to the rest of the tissues of the body

function of deep fascia

-encloses organs

-divides muscles into compartments

-consists of the intermediate layer of deep fascia

What are the 2 main classes of fascia in the neck

-superficial fascia

-deep fascia

What are the tissue layers of the neck from superficial to deep

-skin

-superficial fascia (which contains the subcutaneous fat)

-platysma muscle

-deep cervical fascia

Why is the platysma muscle significant

-all other muscles are found deep to the deep fascia except the platysma muscle

How many layers of superficial cervical fascia are there and what does it enclose

1 layer

encloses the platysma muscle

How many layers of deep cervical fascia are there

3 distinct layers

What are the 3 layers of deep cervical fascia

-investing fascia

-pretracheal fascia

-prevertebral fascia

What is the 4th layer of deep cervical fascia

the carotid sheath

Why isn’t the carotid sheath considered to be a distinct fascial layer

as it is a condensation of the 3 layers (created from the existing deep fascia layers that fuse together)

Role of the carotid sheath

-supports organises and separates viscera, muscles, vasculature and deep lymph nodes

Where does the carotid sheath extend from

extends from the cranial base of the skull to the first rib and sternum T1/T2

Attachments of the carotid sheath

attachments are shared with other layers of deep cervical fascia

Label the different fascial layers

yellow- supercicial cervical fascia

green- investing fascia

dark purple- pretracheal faschia

dark orange- prevertebral fascia

red- (2 circles with the line joining them) carotid sheaths

What are cleavage lines

natural lines of tissue separation

How are cleavage lines formed

formed by fascial planes

Why are cleavage lines useful in surgery

allow for blood-free tissue exploration

useful for surgical investigation fo the neck region

Which layer is the most superficial layer of the deep cervical fascia

investing layer

What des the investing layer enclose

trapezius muscle (posteriorly)

sternocleidmastoid muscle (laterally)

submandibular gland

What are the attachments of the investing layer

superior and inferior bony attachments (attached to specific bones superiorly and inferiorly)

What is the pretracheal layer also known as

the visceral layer

Where does the pretracheal layer span from

spans from the hyoid to the thorax

What are the contents of the pretracheal layer

infrahyoid muscles

trachea

oesophagus

thyroid gland

What is another name for the prevertebral layer

muscular later

What does the prevertebral layer enclose

vertebral column

muscles of the paravertebral region

Attachments of the prevertebral layer

-cranial base (superior)

-endothoracic fascia (inferior)

What is the axillary sheath

-a continuation of prevertebral fascia that continues tot he axilla (armpit)

Are there usually anatomical spaces present between adjacent fascial compartments

no, adjacent fascial compartments of the neck are normally very close to each other and adhere to one another

What can causes potential anatomcial spaces to arises in the fascial planes of the neck

-blood from perforated vessels or pus from infections in the neck can collect as tissue mass in between fascial planes creating potential anatomical spaces

Where are the fascial spaces of the body most exaggerated

-head region

-neck region

-limb regions

How many fascial spaces are in the head and neck region

16

What are the 4 subtypes of fascial spaces of the head and neck

fascial spaces of the face- 5

suprahyoid facial spaces- 5

infrahyoid fascial spaces-1

fascial spaces of the neck- 5

What is the alar fascia

thin fascial membrane that joins the 2 carotid sheaths

What does the alar fascia lie between

-lies between the muscular and visceral compartments of the neck

What is the prevertebral space

-potential space between the prevertebral fascia and the anterior surface of vertebral bodies of the cervical spine

What si the retropharyngeal space

potential space between the alar fascia and the pretracheal fascia

What is the danger space

potential space between the alar fascia and the prevertebral fascia

Label clockwise

middle layer of deep cervical fascia- pretracheal fascia

Superficial infections space

potential space in the neck that lies just under the skin, above the deep cervical fascia

Parapharyngeal space

immediately lateral to the oro and nasopharynx

Importance of the investing layer in relation to infection transmission

-encircles the entire neck and acts as a barrier to superficial abscesses helping to contain infections

Why is an infection between the investing and pretracheal fascia dangerous

-can spread to the thoracic cavity

-can cause mediastinitus

Risks of an abscess posterior to the prevertebral layer

-may extend laterally to the sternocleidomastoid muscle

Risk of an abscess in the retropharyngeal space

-can spread to the superior mediastinum

Risks of infections in the head

-may descend posterior to the oesophagus through the danger space and into the posterior mediastinum