L3: Organisation of the head and neck

Question 1

In what condition can you present with stiff neck (other than meningitis)?

Answer 1

Retropharyngeal cyst (infection of the deep neck)

Question 2

Why would you want to view the neck in cross section?

Answer 2

• to appreciate the organisation and structural relationships in the neck
• similar to radiographic appearance

Question 3

What creates the compartments in the neck?

Answer 3

Concentric fascial layers create compartments for structures running through the neck

Question 4

Why are the facial layers in the neck important?

Answer 4

• form natural planes
• ease of movement b/w structures e.g. when swallowing
• can restrict, but can also permit spread of infection (dependent on direction)
• allow easy separation of tissues in surgery

Question 5

How can the facial layers permit infection spread?

Answer 5

Most of the fascial layers run the whole length of the neck, so there is a possibility that the infection can track inferiorly into the thorax

Question 6

What layer is found directly below the skin in the neck?

Answer 6

Subcutaneous tissue (varying degrees of adipose tissue)
-ALSO KNOWN AS THE SUPERFICIAL CERVICAL FASCIA

Question 7

How many fascial layers are there in the superficial fascia of the neck?

Answer 7

1. Only the cerivcal superficial fascia, which contains superficial blood vessels (anterior/external jugular veins), cutaneous nerves, superficial lymph nodes, platysma muscle

Question 8

Where does the isthmus of the thyroid gland lie?

Answer 8

First few tracheal rings

Question 9

What runs in front of the thyroid gland?

Answer 9

Long strap like muscles: Infrahyoid muscles

Question 10

What group of muscles surrounds the vertebral column in the neck?

Answer 10

Pre/para-vertebral muscles, some running the length of theneck and some running the length of the vertebral column
(scalene muscles included: posterior/anterior/middle)

Question 11

What is the windpipe called before it is called the trachea?

Answer 11

The larynx

Question 12

What is the food pipe known as before the oesophagus?

Answer 12

The pharynx (the trachea is found anterior to the oesophagus)

Question 13

What is found within the visceral compartment of the neck?

Answer 13

Thyroid gland, larynx, trachea, upper oesophagus, hypopharynx

Question 14

What is the hypopharynx?

Answer 14

Tube that is the entrance into the oesophagus

Question 15

What cervical layer is the hyoid bone/thyroid cartilage?

Answer 15

Hyoid bone: C3

Thyroid cartilage: C4-5

Question 16

What are the different deep cervical fascial layers? (in order from more superficial to deep)

Answer 16

1. Deep investing layer of cervical fascia
2. Pre-tracheal fascial layer
3. Carotid sheath
4. Pre-vertebral fascia

Question 17

What does the deep investing layer of cervical fascia envelope?

Answer 17

Completely invests all structures of the neck deep to the platysma and superificial cervical fascia. It splits to encircle the SMC, and splits to encircle the trapezius’, as well as the submandibular and parotid salivary glands

Question 18

What does the pre-tracheal fascial layer encompass?

Answer 18

Thyroid gland, pharynx/oesophagus, larynx/trachea, infrahyoid muscles.
(has a visceral and muscular compartment)
Extends all the way up the neck till the hyoid bone- connects to the hyoid bone

Question 19

Why is it important that the pre-tracheal fascial layer attaches to the hyoid bone?

Answer 19

The hyoid bone moves when we speak/eat, so structures within this fascia are going to move when swalloing/speaking

Question 20

What is special about the pre-tracheal fascia that lies behind the oesophagus?

Answer 20

It is actually known as the buccopharyngeal fascia, it is a continuation of the pre-tracheal fascia.

Question 21

How many deep cervical fascial layers are there?

Answer 21

4

Question 22

What does the prevertebral fascia encompass?

Answer 22

Muscles that are found arround the cervical vertebrae

Question 23

What is the space b/w the buccopharyngeal fascia and the prevertebral fascia called, and its importance?

Answer 23

Retropharyngeal space- where collections of infection/abcess can form (deep neck space)

-the buccopharyngeal fascia runs all the way down the neck, following the oesophagus to the diaphragm. So the infection can travel inferiorly to the thorax/mediastinum, but is restricted laterally by the carotid sheaths

Question 24

What is found in the superior part of the retropharyngeal space in children (<5 yo)?

Answer 24

Retropharyngeal lymphnodes which drain nose/oral cavity/upper pharynx, so when they have upper respiratory tract infections, infections can spread to these lymphnodes, and an abcess may form (retropharyngeal abcess)
i.e. secondary to an upper respiratory tract infection

Question 25

What is it called when you get an infection of your mediastinum?

Answer 25

Mediastinitus

Question 26

What is the difference b/w the thorax and the mediastinum?

Answer 26

The mediastinum is contained within the thorax

Question 27

During dissection what is the immediately visible fascial layer?

Answer 27

Investing layer

Question 28

Where does the investing fascia layer run from?

Answer 28

- Superior margin: entire lower border of the mandible, mastoid process, superior nuchal line (curved line on external surface of the occipital bone), external occipital tuberance - it also attaches to the spinous processes of the vertebrae + ligamentum nuchae posteriorly - Inferior margin: upper border of the manubrium, upper surface of clavicle, spine of scapula

Question 29

Where does the pretracheal layer run from/to?

Answer 29

- the pretracheal layer is thin - superiorly attached to hyoid bone and extends to the thorax where it blends with the fibrous pericardium - buccopharyngeal fascia runs from the base of the skull to the diaphragm

Question 30

Where does the prevertebral layer run from/to?

Answer 30

- From the base of the cranium to the 3rd thoracic vertebra - it then extends laterally as the axillary sheath which surrounds the axillary vessels and brachial plexus of nerves running into the upper limb

Question 31

What are the infective sources of deep neck space infections?

Answer 31

-teeth -tissues of the pharynx -sinuses -middle of ear Spread from there

Question 32

What are the symptoms that present with a retropharyngeal abcess?

Answer 32

- visible bulge on oropharynx (part of throat at back of mouth behind oral cavity) - sore throat - difficulty swallowing - stidor (high pitched wheezing sound caused by disrupted air flow) - high temp - reluctance to move neck

Question 33

How can you localise a lump/swelling in the neck to the thyroid gland?

Answer 33

See whether it moves upon swallowing, as the thyroid gland is enclosed by pretracheal fascia which is connected to the hyoid bone which moves upon swallowing

Question 34

What is retrosternal goitre and its symptoms?

Answer 34

When a goitre extends retrosternally as the pretracheal fascia limit is the thorax. -causes compression of other structures running through the neck e.g. trachea- breathlessnes/stidor, venous blood vessels- facial oedema (impeding venous drainage from head and neck)