1.2 Shoulder and Axilla Flashcards
What artery branches off the 1st part of the axillary artery?
superior thoracic artery
What 2 arteries branch off the 2nd part of the axillary artery?
thoracoacromial artery, lateral thoracic artery
What 3 arteries branch off the 3rd part of the axillary artery?
subscapular artery, anterior circumflex humeral artery, posterior circumflex humeral artery
artery that supplies muscles in the 1st and 2nd rib intercostals, space and serratus anterior, branches off 1st part of axillary artery
superior thoracic artery
short, wide trunk deep to clavicular head of pectoralis minor, divides into 4 branches, comes off 2nd part of axillary artery
thoracoacromial artery
supplies pectoral muscles, axillary lymph nodes, and breast*** (important blood supply to lateral part of mammary gland in women)
lateral thoracic artery
largest branch of axillary artery, divides into circumflex scapular and thoracodorsal
subscapular artery
anterior and posterior, branch off third part of axillary artery, supplies shoulder muscles (deltoid, teres major and minor, long head of triceps)
circumflex humeral arteries
receives directly or indirectly blood from thoracoepigrastric vein, which collects blood from the superficial veins of the inguinal region, blood can bypass when IVC is blocked
axillary vein
two nerves vulnerable during axillary lymph node dissection
long thoracic nerve, thoracodorsal nerve
- adducts and medially rotates humerus
- clavicle head flexes and sternocostal head adducts/medially rotates humerus
- forms most of anterior wall of axilla
- forms deltopectoral groove with the deltoid muscle, cephalic vein runs in this groove
pectoralis major
origin: clavicular head and sternocostal head
insertion: lateral lip of intertubercular groove of humerus
- adducts and medially rotates humerus, flex clavicle
pectoralis major
- origin: coracoid process of scapula
- inserts: ribs 3,4,5
pectoralis minor
- fixes scapula to thoracic wall
- stretches arm forward, helps with inspiration
pectoralis minor
- rotates the inferior angle of the scapula (combing hair)
- holds scapula against thoracic wall (doing pushups)
- forms medial wall of axilla
- protracts the scapula, when punching or reaching anteriorly
serratus anterior
origin: external surface of ribs 1-8
insertion: anterior surface and medial border of scapula
serratus anterior
injury to this nerve will paralyze the serratus anterior, give a winged scapula appearance
long thoracic nerve
- origin: superior nuchal line, C7, T12
- insertion: acromion, spine of scapula
trapezius
-elevates scapula, retracts scapula, depresses scapula and lowers shoulder
trapezius
innervated by spinal accessory nerve Cranial Nerve XI
trapezius
- extends, adducts, and medially rotates the humerus
- brings body toward arms when climbing
latissumus dorsi
innervated by thoracodorsal nerve
latissimus dorsi
- origin: T7, thoracolumbar fascia, iliac crest
- insertion: intertubercular groove
latissimus dorsi
If this nerve is injured there is no counter force for shoulder when pushed up by crutch, can’t climb
latissimus dorsi
- origin: transverse process of C1-C4
- insertion: medial border superior part of scapula
levator scapulae
what muscles are innervated by dorsal scapular nerve?
levator scapulae, rhomboids
- origin: C7, T1, T2, T3, T4, T5
- insertion: medial borders of scapulae
rhomboids
- origin: acromion, spine of scapula, clavicle
- insertion: deltoid tuberosity
deltoid
- abductor (inital 15 degrees by suprspinatus)
- flexion and extension
deltoid
innervated by axillary nerve
deltoid
origin: inferior angle of scapula
insertion: medial lip of intertubercular groove
teres major
- stabilizes humeral head, counteracts deltoid during abduction of the arm
- adduction and medial rotation of humerus
teres major
What artery exits the triangular space b/w teres major and long head of triceps?
circumflex scapular artery
What artery and nerve exit the quadrangular space b/w teres major and long head of triceps?
posterior circumflex humeral artery, axillary nerve
rotator cuff muscles?
supraspinatus, infraspinatus, teres minor, subscapularis
origin: lesser tubercle and greater tubercle
- stabilize shoulder joint
rotator cuff
helps with initial 15 degrees of abduction of arm
supraspinatus
small viscous fluid filled sac lined by synovial membrane
subacromial/subdeltoid bursa