Week 1.1 - Regions of head and neck Flashcards
Which nerve innervates SCM?
-CN XI (accessory)
Describe the insertions of trapezius
- Superior nuchal line to T12
- Lateral 1/3 clavicle
What is the bare area of the clavicle?
-Middle 1/3 where no muscles attach
Which two major vessels are covered by SCM?
- Common carotid
- Internal Jugular
Describe the borders of the anterior triangle
- Imaginary midline -> medial border
- Anterior border of SCM -> lateral argin
- Mandlible - superior margin
- Floor -> vertebrae
Describe the borders of the posterior triangle
- Anterior -> Posterior border of SCM
- Posterior -> Anterior border of Trapezius
- Inferior -> Clavicle
- Floor -> Scalene
- Roof -> fascia
Describe the subdivisions of the anterior triangle
-Hyoid bone divides anterior triangle into 4 smaller triangles: Submandibular Submental Muscular Carotid
What is the purpose of fascial planes in the neck?
- Compartmental
- Allow easy independent movement
- Determine the spread of infection
List the layers of the neck
- Skin
- Superficial fascia
- Subcutaneous fat
- Platysma
- Deep cervical fascia (investing fascia)
- Pretracheal fascia
- Carotid sheaths
- Prevertebral fascia
What muscles are observed in a cross-section of the neck?
- Playsma
- SCM
- Trapezius
Which muscles are invested by the deep cervical fascia?
- SCM
- Trapezius
What is the main advantage of pretracheal fascia?
-Allows for independent movement of the trachea
What does the pretracheal fascia enclose?
- Trachea
- Oesophagus
- Thyroid
- Infrahyoid muscles
What do the carotid sheaths enclose?
- Vagus nerve
- Internal Jugular
- Common Carotid
- Deep cervical LNs
Describe the orientation of the vagus, internal jugular and the carotids
- carotid is anteriomedial
- IJV is anteriolateral
- Vagus is posterior
What does the prevertebral fascia enclose?
-Vertebral column and paraspinal muscles
State the distribution of the prevertebral fascia
-Base of skull to T2/3
What is the clinical importance of the prevertebral fascia spanning down to T2/T3?
-Infection in the neck can track to the mediastinum
Give an example of infection which commonly occur in the superficial layers of the neck
Why is it contained within the superficial layers?
- Cellulitis
- Limited due to superficial fascia
What is the retropharygeal space and why is it clinically significant?
- Space between the pretracheal fascia and prevertebral fascia
- Split into two -> true retropharyngeal (between pretreacheal and alar fascia) and danger space (between alar fascia and prevertebral fascia
- True retropharyngeal connects to superior mediastinum
- Danger space connects to diaphragm so infections can track into the thorax
What is often the cause of a retropharyngeal abscess?
-Rare but infection from node of rouviere
How would someone with a retropharyngeal abscess present?
-Fixed neck due to pain