Regions of the neck Flashcards
Describe the borders of the anterior and posterior neck?
Anterior: inferior border of mandible down to manubrium
Posterior: superior nuchal line down to C7/T1 disc
What are the four fascial layers of the neck?
Superficial fascia
Visceral fascia
Vascular fascia
Vertebral fascia
Give a general description of the fascial layers of the neck?
4 longitudinal compartments each contained within layers of cervical fascia
Describe the superificial fascial layer of the neck?
Contains a thin sheet of muscle called platysma
Blends with facial muscles and shares their nerve supply
Contains EJV
Describe the superficial veins of the neck?
Include their course and structures that they drain.
EJV and AJV
EJV begins at angle of mandible, vertical descent on sternocleidomastoid
Together, drain superifical muscles of neck
What is contained within the visceral fascial layer of the neck?
Thyroid, parathyroid and thymus glands
Also relates to trachea and oesophagus
What is contained within the vascular fascial layer?
Cartoid sheath and contents
What is contained within the vertebral fascial layer?
Cervical vertebrae and postural muscles
Where is the investing fascia located?
What does it contain?
Deep to superificial fascia
Surrounds all layers
Splits to enclose sternocleidomastoid and trapezius
Where is the prevertebral fascia loacted?
What does it contain?
Cylinder surrounding vertebral compartment
Contains vertebrae and postural muscles
Where is the pretracheal fascia located?
What does it contain?
Comprises pretracheal and buccopharyngeal fascia
Preatracheal fascia extends up to hyoid bone
Together surround visceral compartment
What is the significance of the pretracheal fascia connecting to the hyoid bone superiorly?
Hyoid bone moves up and down with swallowing > anything within pretracheal fascia will also move up and down with swallowing
What is the significance of the fascial layers of the neck in terms of communication?
Spaces between fascial layers can communicate up as well as down to medistinum
Allows unrestricted spread of infection
Describe the contents of the carotid sheath?
Common carotid artery/just afetr bifurcation
IJV
CN X
Describe the borders of the anterior triangle of the neck?
In front of sternocleidomastoid
Below inferior border of mandible
To one side of midline of neck (two anterior triangles: right and left)
Describe the borders of the posterior triangle of the neck?
Behind sternocleidomastoid
In front of trapezius
Above middle third of clavicle
Describe the contents of the anterior triangle of the neck?
Anterior vertebral muscles
Carotid system
Veins of neck
Glossopharyngeal, vagus, accessory and hypoglossal nerves
Thyroid gland
What do the anterior vertebral muscles consist of?
Suprahyoid and infrahyoid muscles
Describe the suprahyoid and infrahyoid muscles?
Suprahyoid: connect hyoid bone to skull, constitute floor of mouth, elevate hyoid and larynx
Infrahyoid: anchor hyoid bone down to sternum/clavicle/scapula, depress hyoid or larynx
In which fascial layer do the anterior verebral muscles lie?
Between investing fascia and pretracheal fascia
Describe the actions of the anterior vertebral muscles?
Steady or move hyoid bone and larynx
Suprahyoid: elevates
Infrahyoid: depresses
Describe the innervation of the anterior vertebral muscles?
Anterior rami of cervical nerves
At which level in the neck does the common carotid artery bifurcate?
C3/4 (upper border of thyroid cartilage)
Describe the braches of the internal carotid artery in the neck?
No branches in neck
Describe the branches of the external carotid artery in the neck?
Six branches
Three off the front: superior thyroid artery, lingual artery, facial artery
Two off the back: occipital artery, posterior auricular artery
One deep: ascending pharyngeal artery
What do each of the branches of the external carotid artery in the neck supply?
Superior thyroid artery: turns downards to supply superior thyroid artery from above
Lingual artery: tongue
Facial artery: face
Occipital and posterior auricular arteries: close off vascular supply to face and scalp
Ascending pharyngeal artery: supplies deeper structures associated with pharynx and larynx
Which cranial nerves enter the anterior triangle?
9-12
Those that exit via jugular and hypoglossal formaminae
Describe the pathway of the glossopharyngeal, vagus and spinal accessory nerves into the anterior triangle?
CN IX: goes forwards to oropharynx
CN X: goes downwards, descending in carotid sheath
CN XI: goes backwards, through or beneath sternocleidomastoid into posterior triangle
Describe the pathway of the hypoglossal nerve in the anterior triangle of the neck?
Passes forwards between arterial and venous structures
Describe the structure and location of the thyroid gland?
2 lobes and isthmus, enclosed by pretracheal fascia
Between upper border of thyroid cartilage and 6th tracheal ring
Which additional feature of the thyroid gland may be present in some individuals?
Pyramidal lobe
In 50% people
Often veers to left
Describe the location of the thyroid gland in relation to toher structures in the neck?
Deep to strap muscles
Lateral to trachea and oesophagus as it extends
Adjacent to and overlaps carotid sheaths
Which nervous strucutre is embedded in the thyroid fascia posteriorly?
Recurrent laryngeal nerve
How can enlargement of the thyroid gland present if it impinges on other structures?
Respiratory obstruction due to compression of trachea
Dysphagia due to compression of oesophagus
Hoarse voice due to compression of recurrent laryngeal nerve
Venous distension due to compression of IJV
Describe the blood supply to the thyroid gland?
ARTERIES:
Paried superior thyroid (first branch of external carotid)
Paired inferior thyroid (branch of subclavian)
Anastamoses across midline
VEINS:
Superior, middle and inferior thyroid
Describe the development of the thyroid gland?
What is the significance of this?
Outgrowth from floor of embryonic pharynx
Foramen caecum is origin
Descends ventral to larynx before dividing into two lobes
May end up with aberrant nodules of thyroid tissue anywhere along its descent
Describe the contents of the posterior triangle?
Deep musclesof neck
Subclavian system
CN XI
Peripheral nerves
Where is the beginning of the brachial plexus situated?
In floor of posterior triangle, between scalenus median and anterior
What does the subclavian system supply?
Upper limb
Almost 1/2 brain
Most of spinal cord
Part of thoracic wall
What are the main branches of the subclavian artery in the neck?
Vertebral (first branch)
Thyrocervical trunk
Which important branch does the thyrocervical branch of the subclavian aretry give off?
Inferior thyroid artery
Describe the pathway of CNXI into the posterior trinagle?
Passes into top of anterior triangle from jugular foramen
Turns backwards through sternocleidomastoid and drops onto floor of posterior triangle, crossing it obliquely, then disappears under cover of trapezius
Which peripheral nerves run in the posterior triangle of the neck?
Which structures do they relate to?
Cervical plexus (under SCM, ventral rami of C1-4)
Phrenic nerve (C3,4,5): descends on scalenus anterior
Superficial (cutaneous) branches to skin: emerge from posterior border of SCM
