AH&N- Fascial Layers

Question 1

What causes a double chin?

Answer 1

In obese individuals extra fat is deposited in the superficial fascia.

Question 2

Which fascia do the two heads of the Platysma muscle originate from?

Answer 2

Fascia of the Pectoralis major & deltoid.

Question 3

Name the three layers of the deep cervical fascia.

Answer 3

Investing layer
Pretracheal layer
Prevertebral layer

Question 4

What are the attachments of the investing layer of the deep cervical fascia?

Answer 4

Superior: external occipital protuberance & the superior nuchal line
Anterior: attaches to the hyoid bone
Inferior: to the spine & acromion of the scapula, the clavicle & the manubrium of the sternum.
Posterior: attaches to the ligamentum nuchae

Question 5

Locate and describe the structure of the investing layer of the deep cervical fascia.

Answer 5

Most superficial layer, surrounds all the structures in the neck.
Where it meets the trapezius & SCM it splits into 2 completely surrounding them.

Question 6

Where does the pretracheal layer span?

Answer 6

Spans between the hyoid bone & the thorax where it fuses with the pericardium.

Question 7

What does the pretracheal layer enclose?

Answer 7

Splits into two parts which enclose:
Visceral: encloses the thyroid gland, trachea & oesophagus
Muscular: encloses the infrahyoid muscles

Question 8

What forms the posterior aspect of the muscular fascia of the pretracheal layer?

Answer 8

Formed by contributions from the buccopharyngeal fascia.

Question 9

What are the attachments of the prevertebral layer?

Answer 9

Superior: attaches to the base of the skull
Anterior: attaches to the transverse processes & vertebral bodies of the vertebral column
Posterior: attaches along the ligamentum nuchae
Inferior: fuses with the endothoracic fascia of the Ribcage.

Question 10

What is the function of the anterolateral portion of the prevertebral fascia?

Answer 10

Forms the floor of the posterior triangle of the neck, surrounds the brachial plexus & subclavian artery as they leave the neck forming the Axillary sheath.

Question 11

What does the prevertebral layer enclose?

Answer 11

The vertebral column & it’s associated muscles (scalene, prevertebral & deep muscles of the back)

Question 12

What are the carotid sheaths?

Answer 12

Paired structures which enclose important vessels and nerves.
Formed by contributions from the pretracheal, prevertebral & investing fascia layers.
Contents:
Common carotid, which bifurcated in the sheath to form internal and external carotid
Internal jugular vein
Vagus nerve
Cervical lymph nodes

Question 13

What clinical relevance to fascial layers have?

Answer 13

Define where infections can spread.

Question 14

Where would an infection posterior to the prevertebral fascia spread?

Answer 14

Can erode through the prevertebral fascia & drain into the retropharyngeal space (between pretracheal & prevertebral).
Space extends into the thorax therefore infection can spread to the mediastinal contents.

Question 15

Where can infection between the investing fascia and the visceral part of the pretracheal fascia spread?

Answer 15

This can spread inferiorly into the chest, causing the infection of the anterior mediastinum.

Question 16

Where is the superficial cervical fascia located and what does it contain?

Answer 16

Lies between the dermis & the deep cervical fascia. It contains:
Neurovascular supply to the skin
Superficial veins
Superficial lymph nodes
Fat
Platysma muscle