Posterior triangle of neck, axilla + brachial plexus Flashcards
What are the superior boundaries of the neck?
mandible and posterior skull
what is the inferior boundary of the neck?
thorax and shoulders
what are the boundaries of the posterior triangle?
-INFERIOR BOARDER: Middle 1/3 of the clavicle
-POSTERIOR BORARDER: trapezius
-ANTERIOR BOARDER: sternocleidomastoid (SCM)
What forms the roof of the posterior triangle?
skin, superficial fascia, platysma
What nerves run through the posterior triangle?
● Cutaneous nerves of cervical plexus
● Accessory nerve
● Phrenic nerve
● Brachial plexus rami and trunks
What forms the cervical plexus?
ventral rami of C1-C4 (cutaneous and muscular branches)
What vessels run through the posterior triangle of the neck?
● External jugular vein
● Subclavian vein
● Subclavian artery
which cutaneous branches are in the cervical plexus?
● Lesser occipital nerve
● Greater auricular nerve
● Transverse cervical nerve
● Supraclavicular nerves
How can you test for a spinal accessory nerve injury?
ask patient to preform “idk motion” (raise shoulders and shake head from side to side)
What muscles are innervated by the spinal accessory nerve?
trapezius and SCM
what nerve innervates the diaphragm and what are its spinal levels?
Phrenic nerve
C3,4,5 (keeps the man alive, C4 is major innervation)
If a patient presents with pain in epigastric region and shoulder region what might you suspect happened?
damage to the C4 nerve (if stomach acid escapes the stomach it can reach the phrenic nerve, causing it to not function properly, causing issues to the dermatome and myotomes of C4)
what are the boundaries oft he scalene interval/triangle?
● Anteriorly: anterior scalene muscle
● Posteriorly: middle and posterior scalene muscles
● Inferiorly: first rib
C5-T1 are __ ___ NOT _____ of spinal nerves. However, they are the _____of the brachial plexus
ventral rami, roots, roots
what lays on top of the anterior scalene?
phrenic nerve
what is the most proximal pulse point for evaluating arterial sufficiency in the upper limb
subclavian artery
where can you palpate the subclavian artery?
The subclavian pulse can be evaluated by palpating downward posterior to the clavicle to compress the artery against the
first rib
After the subclavian artery passes what it becomes what?
first rib, axillary artery
what is scalene interval syndrome or thoracic outlet syndrome?
something narrows the scalene interval compressing subclavian artery and/or inferior trunk of brachial plexus
What makes up the apex of the axilla region
clavicle, upper boarder of scapula, 1st rib
What makes up the base of the axilla region?
skin and fascia of armpit
What makes up the anterior wall of the axilla region?
pec major, minor and clavicle
What makes up the posterior wall of the axilla region?
teres major, latissimus dorsi, subscapularis, scapula
What makes up the medial wall of the axilla region?
upper portion of thoracic wall, serratus anterior
What are the contents of the axilla?
● Axillary artery and its
branches
● Axillary vein and its
tributaries
● Brachial Plexus
● Axillary lymph nodes
What makes up the lateral wall of the axilla region?
intertubercular sulcus of humerus
When does the axillary change its name again and what does it become?
Axillary artery changes name to brachial artery at lower border of teres major
What comes off the first part of the axillary artery?
superior thoracic artery
What is in the second part of the axillary artery?
the thoracoacromial trunk and the lateral thoracic artery
The third part of the axillary artery gives rise to :
-the subscapular a.
-anterior and posterior circumflex humeral arteries
where does the axillary vein start? What are its contributes?
the lower border of teres major by joining together of the brachial veins and the basilic vein
What is the function of the musculocutaneous nerve?
Motor: muscles in anterior compartment of arm
Sensory: skin of lateral forearm
Where does musculocutaneous originate? What is its spinal segment?
lateral cord
C5-7
what is the function of the median nerve?
Motor: all muscles in anterior forearm, three thenar muscles
Sensory: skin over palmar surface of three and one half digits, lateral side of palm and middle wrist (look at the image)
What is the function of the ulnar nerve?
Motor: all intrinsic muscles of hand, flexor carpi ulnaris flexor digitorum of profundus
Sensory: palmar surface medial one and half digets (look at picture)
where does the median nerve originate? what are its spinal segments?
medial and lateral cords
C5-T1
What is the function of the axillary nerve?
Motor: deltoid and teres minor
Sensory: skin over upper and lateral forearm
what is the function of the radial nerve?
Motor: all muscles of posterior compartment of arm and forearm
Sensory: skin on posterior arm and forearm, lower lateral surface of arm, dorsal lateral surface of hand
