Flashcards in Lecture 1 - Organisation Of The H&N Deck (53)
What are the borders of the neck?
The neck extends form the lower border of the mandible to the suprasternal notch of the manubrium and the upper borer of the clavicle
How many layers of cervical fascia are there?
1 superficial and 4 deep
What is found in the superficial cervical fascia layer?
Platysma muscle, superficial lymph nodes, cutaneous nerves to the skin of the neck, EJV
What are the 4 deep cervical fascia layers?
Investing layer, pretracheal layer, carotid sheath and prevertebral layer
What is found in the investing layer?
The SCM muscles, trapezius muscles, submandibular and parotid salivary gands
What are the borders of the investing layer?
The investing layer extends form the lower border of the mandible to the mastoid process, spinous process and ligamentum nuchae
What is found in the pretracheal fascial layer?
Infrahyoid muscles in the muscular portion
In the visceral portion is the thyroid gland, the trachea and oesophagus (higher up would be the larynx and pharynx)
What are the borders of the pretracheal fascia layer?
Pretracheal fascial layer extends from the hyoid bone to the pericardium
What is the posterior wall of the pretracheal fascia called and what are its borders?
The buccopharyngeal fascia.
It extends from the base of the skull to the diaphragm
What is found in the carotid sheath?
CCA (then ICA), IJV and vagus nerve
What are the borders of the carotid sheath?
It extends from the base of the skull to the arch of the aorta
What is found in the prevertebral fascia?
Pre and paravertebral muscles and cervical vertebrae
What are the borders of the prevertebral fascia?
It extends form the base of the skull to the T3 vertebral level
What is the space between posteriorly to the buccopharyngeal fascia and anteriorly to the prevertebral fascia called and what is its clinical significance?
Retropharyngeal space - retropharynegal abscesses/infections can spread to the mediastinum to cause mediastinitis which has a high mortality
Although the retropharyngeal space between fascial planes is helpful in allowing the pharynx to move freely on the vertebral column and expand during swallowing.
Up until the age of 3 or 4, the superior part of the retropharyngeal space contains what?
lymph nodes, which drain areas of the nose, oral cavity and upper pharynx.
Diseases affecting the thyroid gland can cause enlargement of the gland or discrete lumps to appear. Asking a patient with a swelling or lump in their neck to swallow and observing whether it moves, can help localise pathology to the thyroid gland. Why?
This is because the thyroid gland is enclosed by pre-tracheal fascia, which is attached to the hyoid bone. The hyoid bone and larynx move up with swallowing, as such so too will the thyroid gland, and any swelling or lump involving this gland.
Why might an enlarged thyroid gland present problems?
It can sometimes extend retrosternally through the root of the neck because the lower border of the pretracheal fascia extends into the thorax.
Retro sternal extension of a goitre can lead to compression of other structures running through the root of the neck like the trachea and venous blood vessels.
What symptoms does compression of the trachea and venous blood vessels lead to?
It leads to breathlessness and stridor (a harsh vibrating noise when breathing caused by obstruction of the larynx or trachea)
It also leads to facial oedema because of compression of the veins drinking the head and neck
What are the two groups of muscles of the H&N?
Muscles of facial expression and muscles of mastication
Why can muscles of facial expression produce facial expressions?
Because they are superficial and therefore their contractions can pull the skin in different directions.
These muscles include the buccinator and occipitofrontalis
What do muscles of facial expression attach to?
To each other, fascia and bone
What do the muscles of facial expression act as (because of their shape)? What is the exception?
They act as sphincters and dilators around the orbits of the face such as the eye, nose and mouth.
One exception to this though is the buccinators (the muscles of your cheek) which, by keeping the cheek taut, helps ensure food remains within the oral cavity proper when chewing (rather than ‘pooling’ between the cheek and teeth).
Which nerve innervates the muscles of facial expression?
The facial nerve and its 5 branches innervate these muscles including the platysma
What are the 5 branches of the facial nerve?
Where does the facial nerve pass through and terminate into its 5 branches?
This happens in the parotid salivary gland
What is the clinical significance of the facial nerve running through the parotid salivary glands?
The nerve and its branches run relatively superficial within the gland, and are vulnerable to damage in facial injuries and in disease or surgery of the parotid glan
Will injury or pathology affecting the facial nerve cause weakness of the muscles of facial expression on the ipsilateral or contralateral side?
What is the most common non-traumatic cause of facial paralysis and does this happen?
Inflammation of the facial nerve which is Bell’s palsy.
There inflammation causes oedema and compression of the facial nerve as it runs through the base of the nerve so the muscles innervated by it are paralysed
Weakness of the facial muscles on one side in association with an ipsilateral parotid enlargement is highly likely to be what?
A parotid cancer