6 - Root of the neck Flashcards
Which artery changes its name at the border of the 1st rib?
Subclavian artery - lateral border of 1st rib - axillary artery
Which vein changes its name at the border of the 1st rib?
Axillary vein - lateral border of 1st rib - subclavian vein
What are the anterior rami (roots) of the brachial plexus?
C5-T1
What are the 3 trunks of the brachial plexus?
- superior
- middle
- inferior
What are the 3 anterior divisions of the brachial plexus?
- superior
- middle
- inferior
What are the 5 terminal branches of the brachial plexus?
- radial
- median
- ulnar
- musculocutaneous
- axillary
What are the 3 posterior divisions of the brachial plexus?
- lateral
- posterior
- medial
What are the 3 cords of the brachial plexus?
- lateral
- posterior
- medial
Describe cervical pleura.
- superior continuation of costal and mediastinal parts of parietal pleura
- superiorly pleura forms pleural cupola
- adheres to thoracic wall, but is distinct from visceral pleura
Where are the cupolas located?
- posterior to SCM
- around 2.5cm above middle 1/3 of clavicle
What is the suprapleural membrane?
- Sibson’s fascia
- strong fibrous connective tissue that is an extension of cervical pleura
- connects to internal surface of 1st rib and transverse process of C7
What is the function of the suprapleural membrane?
Barrier to prevent changes in intrathoracic pressure drawing upon the contents of the neck
What are the branches of the aortic arch?
- brachiocephalic trunk
- left CCA
- left subclavian artery
Describe the course of the subclavian arteries.
- begin posterior to sternoclavicular joints
- ascend through superior thoracic aperture to enter root of neck
- pass the lateral border of 1st rib to become axillary arteries
Describe how the subclavian is divided.
- relative to the anterior scalene muscle
- 1st part is medial to anterior scalene (origin - muscle)
- 2nd part is posterior to anterior scalene
- 3rd part is lateral to anterior scalene (muscle - lateral border 1st rib)
What are the branches of the 1st part of the subclavian artery?
- vertebral
- thyrocervical trunk
- internal thoracic
Describe the course of the vertebral artery.
- ascends in neck as cervical part
- enters C6 foramen transversarium and ascends to C1 as vertebral part
- exits C1 and travels medially to foramen magnum to form basilar artery with opposing vertebral artery
What are the branches of TCT? (3)
Ascends and branches to:
- inferior thyroid artery (1y visceral artery of neck, largest)
- transverse cervical artery
- suprascapular artery
What does the inferior thyroid artery supply?
- thyroid
- parathyroid
- larynx
- trachea
- oesophagus
- prevertebral muscles
- spinal cord
What does the transverse cervical artery supply?
- trapezius (superficial branch)
- rhomboids and scapula (deep branch)
What does the suprascapular artery supply?
Supraspinatus fossa
Describe the course of the internal thoracic artery.
- no branches in neck
- descends posterior to clavicle to 6th intercostal space
- gives rise to anterior intercostal arteries which supply intercostal spaces
What are the branches of the 2nd part of the subclavian artery?
Costocervical trunk
What are the branches of the costocervical trunk?
- supreme intercostal artery
- deep cervical artery
Describe the course of the supreme intercostal artery.
- ascends to 1st rib
- gives rise to posterior intercostal arteries to 1st and 2nd intercostal spaces
Describe the course of the deep cervical artery.
- ascends superiorly to back of neck
- supplies deep cervical muscles
- anastomoses with occipital artery (ECA)
What are the branches of the 3rd part of the subclavian artery?
Dorsal scapular artery
Describe the course of the dorsal scapular artery.
Highly variable origin
Describe the course of the subclavian vein.
- continuation of axillary artery after lateral border of 1st rib
- runs parallel and anterior to subclavian artery
- runs anterior to anterior scalene
- drains into brachiocephalic vein
What is the venous angle?
Where the IJV and subclavian vein join to form the brachiocephalic vein.
What is the thoracic duct?
- major lymphatic drainage channel that ascends from the thorax into the neck
- enters venous system between the left IJV and left subclavian vein
- lymphatic fluid drains into venous system
What are the anterior vertebral muscles?
- longus colli
- longus capitis
- rectus capitis anterior
- anterior scalene
What are the lateral vertebral muscles?
- rectus capitis lateralis
- splenius capitis
- levator scapulae
- middle and posterior scalene (scalene mass)
What is the action of longus colli?
Flexes neck with rotation to opposite side (unilaterally)
What is the action of longus capitis?
Flex head
What is the action of rectus capitis anterior?
Flex head
What is the action of anterior scalene?
Flex head
What is the action of rectus capitis lateralis?
- flex head
- stabilise head
What is the action of splenius capitis?
- laterally flexes and rotates head/neck to same side (unilaterally)
- extends head and neck (bilaterally)
What is the action of the scalene mass?
- flex neck laterally
- middle scalene elevates 1st rib during forced inspiration
- posterior scalene elevates 2nd rib during forced inspiration
What is the action of elevator scapulae?
- elevates scapula
- rotates scapula
