Session 1 Flashcards
From where does the neck extend?
From the lower margin of the mandible to the suprasternal notch of the manubrium and the upper border of the clavicle.
What compartmentalises the structures of the neck?
Layers of cervical fascia. There is a superficial cervical fascia layer just below the skin and four deep cervical fascia layers.
Outline the structure of the superficial cervical fascia
It is a layer of loose connective tissue consisting mostly of adipose. Superficial blood vessels such as anterior and external jugular veins lie within this layer, as do cutaneous nerves, superficial lymph nodes and the platysma muscle.
What are the names of different deep cervical fascia?
The investing layer, the pretracheal layer, and the prevertebral layer(from most superficial to deep)
What is the carotid sheath?
A deep cervical fascia layer that is formed by parts of the other three layers of deep cervical fascia. It encircles several key neurovascular structures that run between the head and the thorax.
Where is the investing layer of the deep cervical fascia found in the body?
Surrounding the entire neck like a collar. It is immediately visible upon dissection of the neck.
Where is the superior margin of the investing layer attached?
It is attached on each side to the entire lower border of the mandible, the mastoid process, the superior nuchal line and the external occipital protuberance in the posterior midline.
Where does the investing layer attach posteriorly?
The spinous processes of the vertebrae and ligamentum nuchae.
Where does the investing layer attach inferiorly?
The upper border of the manubrium, the upper surface of the clavicle, acromion, and spine of the scapula.
What is the function of the investing layer?
It splits to enclose the sternocleidomastoid and trapezius muscles and the submandibular and parotid salivary glands.
Where is the pretracheal layer found in the body?
It is a thin layer that is limited to the anterior and lateral part of the neck.
Where are the attachments of the pretracheal layer?
It attaches to the hyoid bone superiorly and anteriorly. Inferiorly it extends into the thorax where it blends with the fibrous pericardium.
What does the pretracheal layer consist of?
A muscular layer that encloses the infrahyoid muscles and a visceral layer that encloses the thyroid gland, trachea, and oesophagus.
What is the buccopharyngeal fascia?
As the pretracheal fascial layer continues posteriorly to surround the muscles of the pharynx and oesophagus, it becomes the buccopharyngeal fascia. This fascia runs from the base of the skull superiorly to the diaphragm inferiorly.
Describe the structure of the carotid sheath
It is a tubular, fibrous structure that extends from the base of the skull, through the root of the neck, to the arch of aorta.
Which structures are found within the the carotid sheath?
The common carotid artery, the internal jugular vein, the cranial nerve, and the vagus nerve.
What is the function of the prevertebral layer of the cervical fascia?
It forms a sheath for the vertebral column and muscles associated with it.
From where does the prevertebral layer extend?
From the base of the cranium to the third thoracic vertebra.
What is the axillary sheath?
A lateral extension of the prevertebral layer that surrounds the axillary vessels and the brachial plexus.
What do the layers of deep cervical fascia form?
Natural cleavage planes that allow structures to move and pass over one another with ease. This also allows easy separation of tissues during surgery.
How do the layers of deep cervical fascia impact on infection?
They determine the direction and extent to which an infection in the neck may spread. This depends on whether the infection develops within the compartments or between fascial layers.
How are deep neck spaces formed?
The fascial compartmentalisation of structures in the neck gives rise to potential spaces between fascial planes. These spaces contain loose connective tissue,
How do deep neck space infections develop?
The infective source often originates from the teeth, tissues of the pharynx, or sinuses. It then spreads between the fascial planes, causing them to distend. Though these infections are rare, they pose significant threat to life.
Where is the retropharyngeal space found?
Between the prevertebral layer of fascia and the buccopharyngeal fascia, overlying the posterior wall of the pharynx and oesophagus.
What does the retropharyngeal space allow?
The free movement of the pharynx over the surface of the pre-vertebral fascia.
Why is it a big problem when infection spreads to the retropharyngeal space?
The space extends the length of the neck, into the mediastinum. Therefore, retropharyngeal infections can spread inferiorly into the thorax and cause mediastinal complications e.g. mediastinitis.
What does the development of an abscess in the retropharyngeal space usually occur secondary to?
An infection involving the upper respiratory tract that spreads to involve the retropharyngeal lymph nodes.
Why are retropharyngeal abscesses usually seen in young children under the age of 5?
Because in children aged between 3-4, retropharyngeal lymph nodes are present within the suprahyoid region of the retropharyngeal space. Most of these lymph nodes will have atrophied and disappeared by late childhood.
What can cause retropharyngeal abscesses in adults?
Penetrating injury of the oesophagus. This then provides a route for bacteria from the aerodigestive tract to enter the space.
List some potential signs and symptoms of a retropharyngeal abscess.
A visible bulge of the oropharynx, sore throat, difficulty swallowing, stridor (high-pitched wheezing), reluctance to move the neck, high temperature.
List some potential signs and symptoms of a retropharyngeal abscess.
A visible bulge of the oropharynx, sore throat, difficulty swallowing, stridor (high-pitched wheezing), reluctance to move the neck, high temperature.
What is a visible sign that someone may have thyroid gland disease?
Gland enlargement or discrete lump(s) appearing. Asking the patient to swallow and observing whether the lump moves helps localise the pathology to the thyroid gland.
