Root Of Neck Flashcards
Root of neck boundaries
Anterior: top of manubrium and superior border of clavicle
Posterior: T1 and superior margin of scapular to coracoid process
Lateral: 1st pair of ribs
Inferior: superior thoracic aperture and axillary inlets
Cervical pleura
Superior continuation of the costal and mediastinal parts of the parietal pleura
Parietal pleura - serous membranes that line the internal surface of the thoracic cavity
Clinical note: the cervical pleura in children in higher due to shorter neck to more susceptible to injury
Injuries at root of neck
Can compromise the lungs and pleural sacs
Pneumothorax: air outside the lung but within the pleural cavity
Haemothorax: blood entering the pleural cavity
Chylothorax: lymph formed in pleural cavity
Subclavian artery
Origin: left (aortic arch) and right (brachiocephalic)
Course: exits the thorax via the superior thoracic aperture between the anterior and middle scalene muscles before passing between the first rib and clavicle
At the lateral border of the first rib it continues as the axillary artery
Parts:
1 - medial to anterior scalene
2 - posterior to anterior scalene
3 - lateral to anterior scalene
Subclavian artery branches
1st part
Vertebral artery
Thyrocervical trunk
Internal thoracic artery
2nd part
Costocervical trunk
3rd part
Dorsal scapular artery
Vertebral artery
Origin: 1st part of subclavian vein
Course: ascends posterior to ICA in the transverse foramina of C6 and ascends through C1 to C6 as vertebral part
Exits transverse foramina and crosses over posterior tubercle of C1, travelling medially to foramen magnum to join with other vertebral artery to become basillar artery
Supplies: upper part of spinal cord, brainstem and cerebellum and posterior part of brain
Thyrocervical trunk
Origin: 1st part of subclavian artery
Course: ascends superiorly to give off
- inferior thyroid artery (crosses CCA posteriorly and supplies thyroid and parathyroid gland)
- ascending cervical artery (can come off inferior thyroid artery in 60% or thyrocervical trunk in 30% and supplies the prevertebral muscles and spinal cord)
- transverse cervical artery (anterior to anterior scalene and supplies superficial branch to trapezius and deep branch to rhomboids and scapula)
- suprascapular artery (posterior to IJV and SCM and supplies supraspinatus fossa)
Internal thoracic artery
Origin: 1st part of subclavian artery
Course: descends inferomedially posterior to the clavicle into the thoracic cavity and ends at level of 6th intercostal space and gives rise to anterior intercostal arteries that supply the intercostal spaces
Costocervical trunk
Origin: 2nd part of subclavian artery
Course: ascends posters medially and divides into
-supreme intercostal artery: passes between parietal pleura and 1st rib to supply the 1st and 2nd intercostal spaces
- deep cervical artery: ascends superiorly to back of neck to supply deep cervical muscles and anastomoses with occipital artery from ECA
Subclavian vein
Origin: continuation of axillary vein beginning at lateral border of 1st rib
Course: runs parallel and anterior to subclavian artery and anterior to anterior scalene
Joins IJV to drain into brachiocephalic vein
Drains the upper extremities
Cervical sympathetic trunk injury
Damage to cervical sympathetic trunk can result in absence of sympathetically stimulated functions in ipsilateral side of head
Can cause Horners syndrome
- constriction of pupils (miosis) because parasympathetically stimulated sphincter of pupil is unopposed
- drooping of eyelid (ptosis) resulting from paralysis of the smooth muscle component of levator palpebrae superioris
- vasodilation and absence of sweating on face/neck
Pancoast tumours
- located in apex of lung involving apical chest wall and structures of thoracic inlet
- Can get Horners syndrome secondary to pancoast tumour
Symptoms
- severe pain in shoulder radiating towards axillary and scapula and including ulnar distribution of upper arm
- atrophy of hand and arm muscles
- obstruction of subclavian vein resulting in oedema of upper arm
Diagnosis
- made by combination of characteristic clinical symptoms with radiographic findings of mass in apex of lung infiltrating the 1st/2nd ribs
Explain the cervical part of the sympathetic trunk
Sympathetic fibres to the head and neck begin in the spinal cord and need to ascend to reach the head and neck structures
Preganglionic sympathetic fibres from the lateral horn of T1- L2 ascend to reach the neck where they synapse before hitch hiking with arteries to reach their target
Have super middle and inferior cervical ganglia
The levels of the cervical ganglion
Superior cervical ganglion at C1/2
Note: the postganglionic axons from the superior cervical ganglion reach their target organs by forming a plexus around the CCA and its branches
Middle cervical ganglion at C6
Inferior cervical ganglion at C7
Note: the inferior cervical ganglion fuses with the 1st thoracic ganglion to form the cervicothoracic ganglion
