Name the 3 layers of deep cervical fascia, from superficial to deep:
1 - Investing layer
2 - Pretracheal layer
3 - Prevertebral layer
In which cervical fascial layer is the Platysma and the external jugular vein found?
Superficial cervical fascia
Which cervical fascial layers form the carotid sheath?
Deep cervical fascial layers:
- Investing layer
- Pretracheal layer
- Prevertebral layer
What are the attachments of the investing layer of deep cervical fascia?
- Inferior mandible
- Mastoid process
- Superior nuchal line
- External occipital protuberance
- Superior border of manubrium
- Superior border of clavicles
- Spine of scapula
What are the attachments of the pretracheal layer of deep cervical fascia?
Superiorly = Hyoid bone Inferiorly = Blends with fibrous pericardium
What are the 2 layers of the pretracheal layer, and what do they enclose?
1 - Muscular layer = Enclose infrahyoid muscles
2 - Visceral layer = Enclose Thyroid gland, Trachea and Oesophagus
The investing layer splits to invest which key muscles and glands?
- Submandibular salivary glands
- Parotid salivary glands
How can a thyroid goitre cause facial oedema and breathlessness?
Goitre can extend retrosternally as the pretracheal layer extends into thorax.
Therefore goitre can put pressure on trachea = breathlessness.
Goitre can compression the venous drainage from the head and neck = facial oedema.
Name the important contents of the carotid sheath:
- Common carotid artery
- Internal jugular vein
- Vagus nerve
- Cervical lymph nodes
The prevertebral layer of deep cervical fascia extends between which structures?
- Base of cranium
- 3rd thoracic vertebrae (T3)
Which layer of deep cervical fascia forms the axillary sheath (surrounding the axillary vessels and brachial plexus)?
Where is the retropharyngeal space?
Space between the prevertebral and buccopharyngeal (fascia surrounding pharynx) fascial layers
What is found in the retropharyngeal space?
Nothing (lymph nodes up to age 4)
What is the main function of the retropharyngeal space?
Allows pharynx to move freely, and to expand when swallowing
If an infection develops in the retropharyngeal space, how far down in the body can it spread?
To the posterior mediastinum
What age group most commonly develops infections in the retropharyngeal space?
Under 5 yrs
How can a retropharyngeal abscess present?
- Visible bulge on oropharynx
- Sore throat
- Neck stiffness
- High temperature
What is the function of the buccinators?
- Keep cheeks taut
- Aid chewing
What nerve innervates the muscles of mastication?
Trigeminal nerve - Mandibular division
What nerve innervates the muscles of facial expression?
What is Bell’s palsy?
Facial paralysis due to inflammation of facial nerve. Often due to viral infection.
Through which gland does the fascial nerve pass?
What are the main muscles of mastication?
- Medial and lateral Pterygoids
Name the 5 branches of the facial nerve:
1 - Temporal 2 - Zygomatic 3 - Buccal 4 - Marginal mandibular 5 - Cervical
Name the 3 branches of the trigeminal nerve:
1 - Opthalmic
2 - Maxillary
3 - Mandibular
How can you test the facial nerve?
Motor: - Raise both eyebrows - Frown - Close both eyes tightly - Try to open eyes against resistance - Show both upper and lower teeth - Smile - Puff out both cheeks Sensory: - Test for taste
How can you test the trigeminal nerve?
Motor: - Palpate temporalis and masseter as patient clenches jaw - Ask to keep mouth open and side-to-side against resistance - Jaw jerk Sensory = Light touch in 3 divisions: 1) Opthalmic = forehead 2) Maxillary = cheeks 3) Mandibular = chin
Name the boundaries of the anterior triangle of the neck:
Superior = inferior margin of mandible
Laterally = medial border of sternocleidomastoid
Middle - Imaginary sagittal line down midline
Name the boundaries of the posterior triangle of the neck:
Anterior = Posterior border of sternocleidomastoid Posterior = Anterior border of trapezius Inferior = Superior border of medial 1/3rd clavicle
Which nerve innervates the sternocleidomastoid muscle?