Posterior Triangle Flashcards
What are the borders of the posterior triangle?
Anterior border of the trapezius, posterior border of the SCM, and the middle 1/3rd of the clavicle
What muscles comprise the floor of the posterior triangle?
Anterior, middle, and posterior scalene muscles; levator scapulae, and splenius capitis
What cutaneous nerves turn around the posterior border of the SCM then exit from the posterior triangle?
Lesser Occipital, Great Auricular, and Transverse Cervical Nerves
Where do the anterior, middle, and posterior scalene muscles originate and insert*?
Originate: Cervical Transverse Processes
Insert*: 1st Rib; posterior scalene inserts on 2nd rib
What is the relationship of the roots and trunks of the brachial plexus versus the vertebral artery at the transverse processes of the cervical vertebrae?
The nerves will run posterior to the vertebral artery.
Between what two muscles will the ventral ramus of the brachial plexus nerves run through going toward the vertebra?
Middle scalene and Anterior scalene muscles.
Within what structure does the vertebral artery pass?
Within in the transverse foramen
(T/F) The subclavian vein passes through the scalene triangle?
False. It passes anterior to the anterior scalene muscle.
What spinal nerve segments (cervical) contribute to the phrenic nerve?
C3-C5; C4 is most of contribution
On what surface does the phrenic nerve pass?
Anterior surface of the anterior scalene muscle
(T/F) The Phrenic nerve does not lie within the scalene triangle.
True.
What are the clinical presentations of thoracic outlet syndrome (TOS)?
Cold hands from arterial compression, numb fingers from nerve compression, or swelling and blueish colorations from vein compression
What redundant structure developed in a small percentage of the population can cause TOS?
Cervical Rib
What and where is compressed in neurogenic TOS?
Brachial plexus nerves; between scalene muscles and first rib
What and where is compressed in venous TOS?
Subclavian vein; between clavicle and first rib
What causes arterial TOS?
Occlusion or aneurysm of the subclavian artery in the neck associated with an extra “cervical” rib
Where does the subclavian vein join the internal jugular vein?
Posterior to the sternoclavicular joint
What arteries divide posterior to the sternoclavicular joint?
Brachiocephalic trunk divides into right subclavian and right common carotid artery
What structures are between the dividing brachiocephalic trunk and the subclavian vein?
Phrenic Nerve, Vagus Nerve, and Anterior Scalene Muscle
(T/F) The common carotid arteries have branches.
False.
“At the ______ edge of the 1st rib, the subclavian artery becomes the _______ artery”
lateral; axillary
What are the three initial branches off the subclavian artery?
Internal thoracic artery, vertebral artery, and thyrocervical trunk
What is the path of the internal thoracic artery?
Passes posterior to the subclavian vein and first rib into the thorax
What is the origin of the vertebral artery surrounded by?
Sympathetic branches of cervicothoracic ganglion
What vertebral transverse processes does the vertebral artery skip over and which one does it dive into?
Skips 8th and 7th; dives into 6th cervical vertebrae
What foramen does the vertebral artery pass through?
Costotransverse foramen
(T/F) The vertebral artery ascends through the remaining costotransverse foramina anterior to emerging cervical spinal nerves.
True.
Where does the vertebral artery pierce the dura mater to enter the brain?
Foramen Magnum
What does the vertebral artery supply?
Brain, spinal cord, and deep neck muscles
What is the other artery that supplies the brain?
Internal Carotid Artery
What artery forms when the left and right vertebral arteries anastomose?
Basilar Artery
What parts of the body does the thyrocervical trunk supply?
Thyroid Gland and Shoulder
The thyrocervical trunk runs ________ (direction) on the ______ (relation) of the anterior scalene muscle.
superiorly; medial
What structure does the inferior thyroid gland pass to reach the thyroid gland?
Passes deep to the carotid sheath
The inferior thyroid artery passes (anterior/posterior) to the sympathetic trunk, but (anterior/posterior) to the recurrent laryngeal nerve.
posterior; anterior
What branch off the thyrocervical trunk ascends along the anterior scalene to supply muscles in the neck?
Ascending Cervical Artery
What branch of the thyrocervical trunk pins the phrenic nerve down to the anterior scalene?
Suprascapular Artery
What branch of the thyrocervical trunk joins CN 11?
Transverse Cervical Artery
If the costocervical trunk branches posterior to the anterior scalene, what part of the subclavian does it branch from?
2nd part of the subclavian artery
What are the divisions of the costocervical trunk?
Highest intercostal artery and deep cervical artery
What artery branches off the 3rd part of the subclavian?
Dorsal Scapular Artery
What structure parallels the subclavian vein?
Subclavian artery
The subclavian vein passes (anterior/posterior) to the anterior scalene (before/after) joining the internal jugular vein to form the _________ vein.
anterior; before; brachiocephalic vein
What is the only veinous tributary of the subclavian vein?
External jugular vein
At what point do the thoracic duct and right lymphatic duct empty their contents into a vessel?
At the junction of subclavian and internal jugular veins at the most medial aspect of the subclavian vein
What muscles does CN 11 innervate?
SCM and trapezius
Name 3 reasons why CN 11 is not regarded as a spinal nerve.
- Cell bodies of GSE fibers are not located in same region of spinal cord as spinal nerve GSE fibers.
- CN 11 collects from 4-6 different spinal segments to go into a single nerve- unlike spinal nerves.
- Goes up through foramen magnum and exits jugular foramen
What segments join CN 11 to innervate SCM?
C2 and C3
C3 and C4 join CN 11 to innervate what muscle?
Trapezius
To affect all function of CN 11, where would there have to be a lesion?
Medial to the SCM
To affect solely the trapezius, where would CN 11 have to be lesioned?
Lateral to SCM
What is the clinical presentation of a lesion of CN 11 affecting SCM?
Difficulty elevating chin and turning head
What is the clinical presentation of a lesion affecting only the trapezius?
Affected shoulder would droop lower than the other, difficulty elevating shoulder, raising arm above horizontal plane, and squaring shoulders
Where does the sympathetic trunk extend in the neck?
In the space posterior to the carotid sheath along the surface of pre vertebral muscles
Ascending Preganglionic Axons forming the sympathetic trunk primarily enter from what spinal cord segments?
T1 and T2
(T/F) The cervical part of the sympathetic chain receives white rami.
False.
What spinal segments form the superior cervical ganglion?
C1-C4
The fusion of C5 and C6 form what ganglion?
Middle Cervical Ganglion
The cervicothoracic ganglion is a fusion of what spinal segments?
C7, C8, and T1
Many large nodes of the lymphatic chain in the neck lie along what common structure?
Internal Jugular Vein
The lymphatic chain is divided into superior and inferior nodes based on the position of what structure?
Omohyoid Muscle
Superior nodes receive drainage from what space?
Retropharyngeal Space
What is a major node in the superior group of nodes and what structures does it drain?
Jugulodigastric Node; tongue and palatine tonsil
What are inferior deep cervical nodes also called and where do they drain?
Supraclavicular nodes; thoracic duct and right lymphatic duct
