Posterior Triangle Wilson Flashcards
What muscles make up the boundaries of the posterior triangle?
Trapezius, Inf: Omohyoid and clavicle , and SCM
What muscles are contained int the posterior triangle? (They make up the floor)
Levator scapula, Posterior Scalene, Middle scalene, and anterior scalene.
What are the boundaries of the scalene triangle?
Omohyoid, Anterior scalene and middle scalene
What fascia covers the floor of the posterior triangle
Pre-vertebral layer of deep cervical fascia
What are the contents of the scalene triangle?
What is the huge potential of nerve injury in this area?
Trunks of the brachial plexus, Subclavian artery.
Subclavian vein and phrenic nerve are NOT in the triangle
Brachial plexus Injuries are common here.
What are the 5 things that the subcavian artery distributes to?
- Anterior thoracic wall
- Thyroid Gland
- Muscles of the dorsal scapular and superficial back
- Brain and brain stem
- Deep muscles of the anterior cervical region
What is the first branch of the subclavian artery?
Vertebral artery- Arises from the first portion of the subclavian artery ascends between the anterior scalene muscle and longus colli muscles and runs in the transverse processes of C6-C1 and enters the cranial cavity in the foramen magnum
What is the second branch of the subclavian artery?
What are the three branches?
Thyrocervical trunk
Inferior thyroid
Transverse Cervical
Suprascapular
What is the third branch that distributes into the thorax?
Internal thoracic artery- Arises from the first part of the subclavian artery and descends through the thorax behind the upper six costal cartridges and bifurcates into the superior epigastric and musculophrenic
What are the three branches of the thyrocervical trunk?
- Suprascapular artery Passes in front of the anterior scalenes muscle and brachial plexus parallel to but below the transverse cervical artery
- Transverse Cervical Artery Runs laterally across the anterior scalenes muscle, phrenic nerve, and brachial plexus passing deep to the trapezius
- Inferior Thyroid Artery- Ascends in front of the anterior scalenes muscle and turns medially behind the carotid sheeth but in front of the vertebral vessels.
What are the two branches of the costocervical trunk?
Superior Intercostal Artery- Gives rise to the first two posterior intercostal arteries.
Deep Cervical artery- Passes between the transverse process of C7 and the first rib . It anastomoses with the descending occipital artery
Where does the thoracic duct terminate?
At the union between the deep juglar vein and the subclavian vein
Where does the subclavian artery turn into the axillary artery
When it passes between the clavicle and the first rib.
If you wanted to compress the subclavian artery where could you do that?
Just medial to the clavicle you can compress the subclavian artery against the first rib
Where would be a potential place to perform a jugular vein puncture
Above the sternal notch through the SCM muscle.
Where could you perform a subclavian vein puncture?
Medial to the axillary pulse at the clavicle
What nerve courses through the posterior triangle?
Accessory Nerve
What are the causes of thoracic outlet syndrome?
- Cervical Rib
2. Pancost Tumor