Neck Flashcards
Describe the superficial fascia of the neck (what kind of layer)
Subcutaneous layer of adipose connective tissue
What are the 4 contents of the superficial fascia of the neck?
1-Fat (of variable amount)
2-superficial lymph nodes
3-cutaneous nerves and vessels which supply the overlying skin
4-Platysma muscle
What are the fasciae within the deep cervical fascia?
Deep investing fascia
Visceral (pretracheal) Prevertebral
Alar
Carotid sheaths
Give a description of the deep investing fascia
Deep to superficial fascia
Wraps around the entire circumference of the neck like a fibrous collar
What are the contents of the deep investing fascia?
The entire neck and its viscera
Encloses separately the sternocleidomastoid and the trapezius
Where does the deep investing fascia attach superiorly?
superiorly: 1- inferior border of the mandible 2-body of hyoid 3-zygomatic arch 4-angle of mandible 5-mastoid process 6-styloid process
Where does the deep investing fascia attach inferiorly?
1-Manubrium of sternum 2-clavicles 3-spines of scapulae 4-sternocleidomastoid 5-trapezius
Where does the deep investing fascia attach posteriorly?
Ligamentum nuchae
What is important about the deep investing fascia’s attachment to the manubrium?
As it descends to the manubrium, the deep investing fascia divides into anterior and posterior sheets, creating the suprasternal space.
What does this suprasternal space contain?
1-areolar tissue 2-fat 3-lymph nodes 4-portions of inferior thyroid veins 5-portions of anterior jugular venous arch
Give a description of the visceral/pretracheal fascia.
Deep to deep investing fascia
Forms sheath around visceral unit of neck
What are the contents of the visceral unit of the neck?
- pharynx –> oesophagus at C6
- larynx –> trachea at C6
- thyroid gland
Where does the visercal fascia arise from superiorly?
1-hyoid bone
2-shared attachment with pharynx to base of skull
Where does the visceral fascia extend to inferiorly and what does it blend with?
-superior mediastinum
blends with pericardium of heart
What is the retropharyngeal space?
a fascial space behind the pharynx through which serous infections can spread down into the posterior mediastinum. (infections of the caused by impacted wisdom teeth)
Give a description of the prevertebral fascia.
Posterior to the visceral unit
Surrounds the vertebral unit
What are the contents of the prevertebral fascia?
The vertebral unit
What is contained within the vertebral unit?
- 7 cervical vertebrae
- cervical portion of spinal cord
- 8 paired spinal nerves
- anterior vertebral muscles (flex)
- posterior vertebral muscles (extend)
- extends laterally into axillary sheath
What is contained within the axillary sheath?
The brachial plexus
The Subclavian vessels
What are the superior attachments of the prevertebral fascia?
Base of the skull
What are the inferior attachments of the prevertebral fascia?
-posterior portion of sheath blends with investing fascia of back muscles
anterior portion of sheath blends with anterior longitudinal ligament of thoracic verebrae
Give a description of the Alar fascia.
Between the prevertebral and visceral units
What are the contents of the alar fascia?
Formed by division of anterior component of prevertebral fascia to form 2 potential spaces between the two units
What are the attachments of the alar fascia and why does it attach here?
Binds to transverse processes on either side to limit the space laterally
What is so vital about the alar space and the spread of infection?
The alar space extends from the base of the skull to the superior medastinum so infection can travel straight to the thorax!!!!!!!!!!!
What are the spaces (retropharyngeal and alar) between deep cervical fascia filled with?
Loose areolar connective tissue.
When do potential spaces within deep cervical fascia become real spaces?
Only when invaded and displaced by infective material (PUS) or occasioanlly by air (SURGICAL EMPHYSEMA)
Give a description of the bilateral carotid sheaths.
Lateral to the visercal unit
Bilateral tubes of fasica which extend from the base of the skull to the thoracic inlet
What is contained within the carotid sheaths?
Bilateral: Common carotid artery Internal jugular vein Vagus nerve (CN X) Deep cervical lymphnodes
What are the superior attachments of the carotid sheaths?
The base of the skull around the:
- carotid canal
- jugular foramen
What are the anterior attachments of the carotid sheaths?
blends with visceral fascia
What are the posterior attachments of carotid sheaths?
blends with prevertebral fascia
What are the of benefits tubes of deep cervical fascia
prevent spread of infection from one compartment to another
What is formed when the anterior rami of spinal nerves intertwine?
A plexus
What do the anterior rami of spinal nerves give?
Sensor innervation
What spinal nerves intertwine to for the cervical plexus?
C2, C3 and C4
what does the cervical plexus give sensory innervation to?
The neck
The shoulders
The corner of the face (at angle of the mandible)
How do the sensory nerves of the cervical plexus reach the spinal cord?
Leave the skin and superficial fascia and pierce the deep fascia to reach the spinal cord
What is a ‘nerve point’?
Where the plexus goes deep
Where is the nerve point of the neck?
Posterior to the middle of the sternocleidomastoid’s posterior border
Describe the platysma muscle including innveration, blood supply, origin, insertion and action
A thin flat muscle within superficial fascia which overlies the sternocleidomastoid.
Innervated by: CN VII
Supplied by:branches of the Submental artery and Suprascapular artery
Originates: subcutaneous tissue of infraclavicular and supraclavicular regions
Inserts: base of mandible; skin of cheek and lower lip; angle of mouth; orbicularis oris
Action: Draws the corners of the mouth inferiorly and widens it (as in expressions of sadness and fright). Also draws the skin of the neck superiorly when teeth are clenched
Where do the superficial veins of the neck lie within?
The superficial fascia
What are the superficial veins of the neck all part of?
The jugular venous system
Where do superficial veins of neck drain to?
“Deep” internal jugular veins
What are the 3 bilateral jugular veins called?
External jugular
Anterior jugular
Superior jugular communicating
What are the branches of each of these bilateral jugular veins?
Posterior auricular vein directly into external jugular
Retromandibular posterior division directly into external jugular
Retromandibular anterior division and facial into common facial
Common facial into superficial jugular communicating
Anterior jugular and superficial jugular communicating superficially cross over internal jugular to drain into external jugular
What potential space sits more anterior to the other?
The retropharyngeal space sits anterior to the alar space (important in sagittal cross section )
