Intro Flashcards
Give a brief overview of the Innervation of the head and neck
Cranial nerves, arising from the central nervous system (mainly the brainstem) innervate structures of the head and neck, and course through the skull to reach their target tissues; for some nerves, their route involves passing through the whole, or part of, the length of the neck.
Give a brief overview of the vasculature of he head and neck
Blood vessels supplying head and neck structures arise from or drain into branches of large arteries (common carotids) and veins (subclavian veins). These vessels ascend and descend up and down through the neck from and to the thorax, in close proximity to the thyroid gland, aerodigestive tracts, muscles and cervical vertebrae.
Common carotid artery is main arterial supply via
its terminal branches
• Internal carotid artery
• External carotid artery (facial artery branch
supplies face)
• Internal jugular vein (IJV) is the main vein draining
head and neck structures
• Receives the venous drainage from the face
(facial vein)
• External jugular vein also receives veins draining
the scalp and face and runs much more
superficially than the IJV
What area constitues the neck
The neck extends from the lower margin of the mandible (jaw) to the suprasternal notch of the manubrium and the upper border of the clavicle below, connecting the head to the rest of the body.
How many cervical fascia layers are there ?
Structures in the neck are compartmentalised by layers of cervical fascia. Broadly speaking there is a superficial cervical fascial layer, just below the skin, and three deep cervical fascial layers.
Describe the superficial cervical fascial layer and what it contains
Loose connective tissue layer largely containing adipose. Within this layer lie superficial blood vessels e.g. anterior and external jugular veins, cutaneous nerves, superficial lymph nodes and the platysma muscle.
What are the 3 layers of deep cervical
The three layers of deep cervical fascia, from most superficial to deep are: the investing layer, the pretracheal layer (middle), and the prevertebral layer (deep).
What is the carotid sheath?
The carotid sheath is formed by all three layers of deep cervical fascia and creates a compartment for a number of neurovascular structures running between the head and thorax.
What fils the spaces between fascial planes?
Loose connective tissue
What happens if infection occurs between the fascal planes, and where does it arise from?
infection or an abscess can arise between the planes causing the spaces to distend. (deep neck space infections). The infective source often originates in the teeth, tissues of the pharynx , sinuses or middle ear, and spreads. Although deep neck space infections are thankfully rare, they pose significant risk to life. It is important therefore, that doctors are aware of how deep neck space infections present and the risks they pose.
What is the retropharyngeal space and where is it located? (See app)
The retropharyngeal space, is one deep neck space (there are others), and lies between the prevertebral layer of fascia and the fascia surrounding the pharynx and oesophagus (buccopharyngeal fascia). Up until the age of 3- 4 years, the superior part of this space contains lymph nodes, which drain areas of the nose, oral cavity and upper pharynx
What does he retropharyngel space allow, and what can go wrong with it?
While this چspaceڇ between fascial planes allows the pharynx to move freely on the vertebral column and expand during swallowing, it presents significant problems should infection spread to and collect here. As the retropharyngeal space lies between fascial layers that extend the length of the neck, into the mediastinum, retropharyngeal infections may spread inferiorly into the thorax, risking the development of mediastinitis (rare, but life-threatening condition).
What are the branches of the facial nerve and what o they innervate
Muscles of facial expression
Temporal, zygomatic, buccal, mandibular,cervical
What is the trigeminal nerve and what are the branches
Trigeminal (cranial nerve V) • Main sensory nerve of face and scalp • Three key branches • Va ophthalmic division • Vb maxillary division • Vc mandibular division • Motor to muscles of mastication
What are the muscles of the neck
Muscles to note – Platysma – Trapezius – Sternocleidomastoid – Scalene muscles – Supra- and infra-hyoids Form the boundaries of two neck “triangles” Floor of one of the neck triangles • Located above and below the hyoid bone • Supra-hyoids supplied by cranial nerves • Infra-hyoids supplied by cervical nerves (C1-3)
Describe the fascialcompartments
• View the neck in cross-section
– Easier to appreciate organisation and structural relationships
– Relates to radiographic appearance
(e.g. CT imaging)
• Concentric fascial layers create compartments of structures running through the neck
