Session 1.1b - Pre-Reading (Organisation of the Neck) Flashcards
Organisation of the Head & Neck VIDEO, pre-reading for Lecture 1 https://www.youtube.com/watch?v=kqwupuoCOzs
What does the neck act as a conduit or passageway for?
Structures running between the head and thorax
What important structures does the neck contain from the respiratory and GI system?
Larynx
Trachea
Pharynx
Oesophagus
What is the best way to visualise the neck?
Via cross-section
- this helps us to appreciate the anatomical arrangement and relationships of the different structures
How are neck structures arranged?
Into ‘compartments’
Other than the neck, what other structures are organised into compartments?
Upper and lower limb
How are the structures through the neck compartmentalised?
Compartments created by fibrous sheets of tissue which are concentrically arranged, called fascia.
Broadly speaking, where do the fascia run?
For the most part, they run the length of the neck, from the base of the skull onto the chest wall or into the thorax.
What is the fascia in the neck called?
Cervical fascia
Cervical = neck
There are a number of cervical fascial layers. What are the two broad categories?
Superficial or deep.
How many layers of superficial cervical fascial layers are there?
One
Where does the cervical fascial layer lie?
Immediately below the skin
What does the superficial cervical fascial layer consist of?
- Very loose connective tissue
- Fat
- Superficial LNs
- Superficial blood vessels, e.g. external jugular vein
- Cutaneous nerves supplying the skin of the neck
- Platysma muscle
What tissue type is the superficial cervical fascial layer?
Loose connective tissue
Give an example of a blood vessel that runs through the superficial cervical fascial layer
External jugular vein
What do the nerves of the superficial cervical fascial layer supply?
They are cutaneous, thus supply the skin of the neck.
What muscle is found in the superficial cervical fascial layer?
Platysma
Describe the platysma muscle’s location, and its origin and insertion.
Arises from the lower part of the face at the inferior border of the mandible
Descends down the neck
Blending onto the clavicle, sternum and anterior chest wall.
What is the platysma’s origin?
Clavicle, sternum and anterior chest wall area
What is the platysma’s insertion?
Inferior border of the mandible (lower part of the face)
How many deep cervical fascial layers are there?
4 (including the carotid sheath)
How are the deep cervical fascial layers named?
Broadly - ‘deep’ because it is deeper than the superficial layer
The individual layers are named depending on the structures that they enclose
What type of tissue is deep cervical fascia?
Dense connective tissue
Which of these, if any, has denser connective tissue, and is therefore tougher?
- Superficial cervical fascia
- Deep cervical fascia
The deep cervical fascia is denser and tougher (dense CT)
The superficial cervical fascia consists of loose CT.
Image 1:
What layers have we removed to create this image?
The skin and superficial cervical fascial layer
Image 2:
What level are we looking at here?
Directly looking at the first of the deep cervical fascia layers i.e. investing layer
Image 3:
At approximately what layer is this cross-section taken?
C7
??? Check
Image 4:
If this image is depicting the first layer of deep cervical fascia, which layer is this red circle depicting and what do the labels mean?
The red circle must be showing the investing layer.
ANT represents anterior (front of the neck), and POST represents posterior (back of the neck), whilst the L and R indicate left and right, respectively.
Image 4:
From what position are we visualising this cross-section drawing?
We are looking from the feet up towards the head i.e. in the same way we would view CT images.
What is the first layer of deep cervical fascia?
The investing layer
What structure do we find most anteriorly running through the neck (particularly at the level of this cross-section)?
The thyroid gland
What is the structure of the thyroid gland when we’re looking at it directly, front on?
It is H-shaped, with a central isthmus and two lateral lobes either side
Image 5:
Name this structure
The thyroid gland
Image 6:
Name the structure and this part of the structure
The central isthmus of the thyroid gland
Image 7:
Name the structure and this part of the structure
The lateral lobe of the thyroid gland
Image 5:
Why does the thyroid gland in this image not look like the classical thyroid gland normally depicted in images (‘H-shaped’)?
The level at which the cross-section was taken (approx. C7) cuts right through the thyroid gland at the level of the isthmus. Therefore, the central isthmus and the two lateral lobes are pictured but the thyroid gland is essentially cut in half transversely. (See Image 8)
What structure is immediately behind the thyroid gland?
The trachea
Image 9:
What structure lies immediately behind the thyroid gland?
The trachea
The trachea lies immediately behind which structure?
The thyroid gland
What is the trachea a continuation of?
The larynx
The larynx continues on to form which structure?
The trachea
About which level does the larynx ends and the trachea begins?
C6
What is found immediately behind the trachea?
The oesophagus
Which structure lies posterior to the thyroid gland and anterior to the oesophagus?
The trachea
The oesophagus is found posterior to which structure(s)?
The trachea (and the thyroid gland).
The oesophagus is a continuation of which structure?
The pharynx
The pharynx continues on to form which structure?
The oesophagus
At which level does the pharynx end and the oesophagus begins?
C6
At the back of the neck you find a very ____, ________ area.
Bony, muscular
What is found in the bony muscular area at the back of the neck?
Cervical vertebrae surrounded by a number of muscles
Which vertebrae are found in the neck?
Cervical vertebrae
Many of the muscles associated with the cervical vertebra run where?
Many run the length of the neck and the spine
What is the collective name for muscles that run the length of the neck and spine (i.e. associated with the cervical vertebra)?
Pre- and paravertebral muscles.
Image 10:
Label this structure.
The oesophagus
Image 11:
Label the cervical vertebra in this image
Spinous object posteriorly in the neck.
Image 11:
Label the posterior structures in this image.
Cervical vertebra, surrounded by pre- and paravertebral muscles (note: these muscles are drawn roughly, and do not necessarily represent the exact number of these muscles - the purpose of the image is merely to indicate that there are quite a few muscles surrounding the vertebra.
What is the function of the pre- and paravertebral muscles?
These are the muscles that surround the cervical vertebra, which act to anchor the head to the neck and the rest of the body.
What lies between the oesophagus and the prevertebral muscles/cervical vertebrae?
A number of neurovascular structures that are running up and down the neck between the thorax and the head. These are within their own fascial compartment, known as the carotid sheath.
A number of neurovascular structures are found in the carotid sheath of the neck. Where do they run?
Up and down the neck between the thorax and the head.
Many neurovascular structures are found in the neck, posterior to the oesophagus and anterior to the prevertebral muscles. What fascial compartment are they found in?
These are within their own fascial compartment, known as the carotid sheath.
The carotid sheath is a part of which cervical fascial layer?
It is its own separate layer in the realms of deep cervical fascia.
Image 12:
What are the green circles?
The carotid sheath
Image 12:
Label the carotid sheath.
Green circles
What does the carotid sheath contain?
Neurovascular structures that are running up and down the neck.
At the level of this cross-section, what artery would you expect to find in the carotid sheath?
The level of the cross-section is about the level of C7 (due to the thyroid gland being split in two, and the central isthmus being visible).
This means you would expect to find the common carotid artery.