Scapular & Pectoral Regions Flashcards
What are the two joints associated with the UL that are considered bony articulations (not muscle attachments)?
Sternoclavicular & acrmoioclavicular
What are the two components that comprise the coracoclavicular ligament?
Trapezoid (more lateral) and coroid (more medial) ligaments
What are the rotator cuff muscles?
SITS = supraspinatus, infraspinatus, teres minor, subscapularis
Deltoid origin
Lateral clavicle, acromion, and spine of scapula
Deltoid insertion
Deltoid tuberosity of humerus
Deltoid action
Abducts humerus (primary function), flexes, extends, and rotates humerus (secondary function)
Deltoid supply
Axillary n & posterior circumflex humeral vessels (located in quadrangular space)
Teres Major origin
Inferior angle of scapula
Teres Major insertion
Crest of lesser tubercle of humerus
Teres Major action
Medially rotates & extends humerus
Teres Major supply
Lower (inferior) sub scapular n & subscapular vessels
Supraspinatus origin
Supraspinous fossa
Supraspinatus insertion
Greater tubercle of humerus
Supraspinatus action
Initial 15 degrees of humerus abduction (then deltoid takes over)
Supraspinatus supply
Suprascapular n & vessels & dorsal scapular vessels
Infraspinatus origin
Infraspinous fossa
Infraspinatus insertion
Greater tubercle of humerus
Infraspinatus action
Laterally rotates humerus
Infraspinatus supply
Suprascapular n & vessels & subscapular vessels
Teres Minor origin
Lateral border of scapula
Teres Minor insertion
Greater tubercle of humerus
Teres Minor action
Lateral rotation of humerus
Teres Minor supply
Axillary n & suprascapular & subscapular vessels
Subscapularis origin
Subscapular fossa
Subscapularis insertion
Lesser tubercle of humerus (more medially located than greater tubercle)
Subscapularis action & supply
Medial rotation of humerus
Upper & lower subscapular nn and subscapular vessels
What are the boundaries of the quadrangular space?
Superior: Teres Minor
Inferior: Teres Major
Medial: Long head of Triceps Brachii
Lateral: Surgical neck of humerus
What is contained within the quadrangular space?
Axillary n & posterior circumflex humeral vessels
What are the boundaries of the triangular space?
Superior: Teres Minor
Inferior: Teres Major
Lateral: Long head of Triceps Brachii
What is contained within the triangular space?
Circumflex scapular vessels
What are the boundaries of the triangular interval?
Superior: Teres Major
Medial: Long head of Triceps Brachii
Lateral: Lateral head of Triceps Brachii
What is contained within the triangular interval?
Radial n & Deep Brachial a
What makes up the suprascapular nerve?
Ventral rami of C5-C6
Where does the suprascapular artery come from?
Thyrocervical trunk
What ligament is associated with the suprascapular n & a? Which goes over/under?
The nerve runs under superior transverse scapular ligament through the suprascapular notch, while the artery runs over the ligament above the notch
Suprascapular n & a action
Both pass through spinoglenoid notch to infraspinatus fossa & supply supraspinatus & infraspinatus mm
What makes up the dorsal scapular nerve?
Ventral rams of C5
Where does dorsal scapular artery come from?
Subclavian a or deep transverse cervical artery
Dorsal scapular n & a action
Both run parallel to vertebral border of scapula & supply levator scapulae & rhomboid mm
CN XI runs with which artery?
Transverse cervical artery
Where does transverse cervical artery come from?
Thyrocervical trunk
CN XI & transverse cervical a action
Both supply Trapezius m
Where do the upper and lower subscapular nerves come from?
Posterior cord of brachial plexus; ventral rami of C5-C6
Where does subscapular artery come from?
Third part of axillary artery
What are the two branches of the subscapular artery?
Thoracodorsal artery & circumflex scapular artery
Upper & lower subscapular nn & a action
All supply subscapularis m
What other muscle do lower subscapular n and subscapular a also supply?
Teres Major m
Collateral circulation of the scapular region is performed by which arteries?
Thyrocervical trunk & subscapular a
Ligating anywhere distal to what artery inhibits blood flow to UL?
Subscapular a
What two heads is Pectoralis Major divided into?
Clavicular and sternocostal heads
What fascia is Pectoralis Minor enveloped in?
Clavipectoral fascia
Pectoralis Major origin
Clavicle, sternum, and ribs 2-6
Pectoralis Major insertion
Crest of greater tubercle of humerus
Pectoralis Major action
Adducts & medially rotates humerus
Pectoralis Major supply
Medial & lateral pectoral nn & thoracoacromial vessels
Pectoralis Minor origin
Ribs 3-5
Pectoralis Minor insertion
Coracoid process of scapula
Pectoralis Minor action
Protracts scapula
Pectoralis Minor supply
Medial pectoral n & thoracoacromial vessels
What arteries supply the pectoral region?
Lateral & internal thoracic (mammary) arteries, thoracoacromial artery
Lateral thoracic artery is a branch of which artery?
Second part of axillary artery
Lateral thoracic artery runs with which nerve?
Long thoracic nerve
What does lateral thoracic artery supply?
Lateral thorax, lateral pec region, and lateral breast
Internal thoracic artery is a branch of what artery?
Subclavian a (inside thorax)
What is the pathway of internal thoracic artery?
Descends across intercostal spaces lateral to sternum
What does internal thoracic artery supply?
Anterior thorax, medial pectoral region, and medial breast
Thoracoacromial artery is a branch of which artery?
Second part of axillary artery
What are the four branches of thoracoacromial artery?
Pectoral, clavicular, acromial, deltoid
What kind of innervation is supplied by cutaneous nerves?
General sensory
Where do cutaneous nerves originate?
T1-T6
What are the branches off the cutaneous nerves?
Lateral & anterior cutaneous branches of intercostal nerves
Where does the medial pectoral nerve originate?
Medial cord of brachial plexus
From where is the medial pectoral nerve derived?
Ventral rami C8-T1
What muscle does medial pectoral nerve pierce?
Pectoralis minor m to enter Pectoralis major m
What muscles does medial pectoral nerve supply?
Pectoralis minor & part of Pectoralis major
Where does lateral pectoral nerve originate?
Lateral cord of brachial plexus
From where is lateral pectoral nerve derived?
Ventral rami C5-C7
What does lateral pectoral nerve supply?
Remainder of Pectoralis major muscle
From where is long thoracic nerve derived?
Ventral rami C5-C7
What muscle does long thoracic nerve supply?
Serratus anterior m superficially
Damage to long thoracic nerve (common during mastectomy) results in what?
“Winged scapula” = lose the close adherence of scapula to posterior wall
