Superficial Back, Posterior Axilla & Scapular Region

what are the proximal attachments of trapezius?

external occipital protuberance

medial 1/3 of the superior nuchal line of occipital bone

nuchal ligament

spinous processes C7-T12

what are the distal attachments of trapezius?

clavicle (lateral 1/3)

acromion

scapular spine

what are the actions of the upper trapezius?

elevate scapula, draw head laterally & assist upward rotation of the scapula in humeral abduction

what is the motor innervation of trapezius?

spinal nerves C3-C4

what are the actions of middle trapezius?

scapular adduction & assist upward rotation of the scapula during humeral abduction

what is the vascular supply for the middle trapezius?

transverse cervical artery

what are the actions of lower trapezius?

depress scapula & assists in upward rotation of the scapula during humeral abduction

what is the vascular supply for lower trapezius?

suprascapular artery

what are the proximal attachments of latissimus dorsi?

thoracolumbar fascia & spinous processes of T6-T12 & L1-L5; sacrum & iliac crest

what are the distal attachments of latissimus dorsi?

humerus (intertubercular groove)

what are the actions of latissimus dorsi?

extension, adduction, internal rotation of humerus; elevates trunk to arms

what is the innervation of latissimus dorsi?

thoracodorsal nerve from posterior cord of the brachial plexus (C6, C7, C8)

what is the blood supply for latissimus dorsi?

thoracodorsal artery

what is the proximal attachment of rhomboid major?

spinous processes of T2-T5

what is the distal attachment of rhomboid major?

medial border of scapula between scapular spine and inferior angle

what are the actions of rhomboid major?

retracts (ADD) scapula; downward rotation of scapula; helps fix scapula to thoracic wall

what is the innervation for rhomboid major and minor?

dorsal scapular (C4, C5)

what is the blood supply for rhomboid major and minor?

dorsal scapular - deep branches of the transverse cervical artery

what is the proximal attachment of rhomboid minor?

spinous processes of C7-T1, inferior nuchal ligament

what is the distal attachment of rhomboid minor?

medial border of scapula at root of spine

what is the action of rhomboid minor?

assists rhomboid major

what is the proximal attachment of levator scapulae?

transverse processes of C1-C4

what are the distal attachments of levator scapulae?

medial border of the scapula from the superior angle of scapula

what is the action of levator scapulae?

elevates scapula; tilts glenoid downward

what is the motor innervation of levator scapulae?

dorsal scapular nerve (C5)

what is the sensory innervation of levator scapulae?

spinal nerves C3-C4

what is the blood supply to levator scapulae?

transverse cervical artery, dorsal scapular artery

what are the borders and significance of the triangle of auscultation?

latissimus dorsi, trapezius, rhomboid major

the triangle enlarges when the arm is drawn across the body

in this space respiratory sounds can be heard

what is the proximal attachment of anterior deltoid?

lateral 1/3 of clavicle

what is the distal attachment of the deltoid?

deltoid tuberosity

what are the actions of the anterior deltoid?

abduction and assists flexion and internal rotation of the humerus

what is the proximal attachment of middle deltoid?

acromion

what is the action of the middle deltoid?

abduction of the humerus

what is the proximal attachment of posterior deltoid?

scapular spine

what are the actions of posterior deltoid?

abduction; extension of the humerus

what is the innervation of the deltoid?

axillary nerve (C5, C6) from posterior cord of brachial plexus

what is the blood supply to the deltoid?

posterior humeral circumflex artery, deltoid branch of the thoracoacromial artery

what is the proximal attachment of teres major?

lower lateral border and inferior angle of scapula

what is the distal attachment of teres major?

crest of lesser tubercle and medial lip of intertubercular sulcus

what are the actions of teres major?

adduction, internal rotation of the humerus; assists in extension of the humerus

what is the innervation of teres major?

lower subscapular nerve (C5, C6) from posterior cord

what is the blood supply to teres major?

scapular circumflex artery

what is the proximal attachment of supraspinatus?

supraspinous fossa of scapula

what is the distal attachment of supraspinatus?

highest facet of greater tubercle of humerus

what are the actions of supraspinatus?

initiates (first 30 degrees) of humeral abduction, external rotation of the humerus, stabilize GH joint

what is the innervation for supraspinatus?

suprascapular nerve (C4, C5, C6)

what is the blood supply for supraspinatus?

suprascapular artery

what is the proximal attachment of infraspinatus?

infraspinous fossa of scapula

what is the distal attachment of infraspinatus?

middle part of the greater tubercle of the humerus

what is the action of infraspinatus?

external rotation of the humerus

what is the innervation for infraspinatus?

suprascapular nerve (C5, C6)

what is the blood supply for infraspinatus?

suprascapular artery

transverse scapular artery

scapular circumflex artery

what is the proximal attachment for teres minor?

upper part of the lateral border of the scapula

what is the distal attachment of teres minor?

lower part of the greater tubercle

what are the actions of teres minor?

external rotation of the humerus; weakly adduction of the humerus; stabilize humeral head in the glenoid fossa

what is the innervation of teres minor?

axillary nerve (C5, C6)

what is the blood supply for teres minor?

scapular circumflex artery

what is the proximal attachment of subscapularis?

subscapular fossa

what is the distal attachment of subscapularis?

lesser tubercle of humerus

what are the actions of subscapularis?

medial rotation of the humerus; can assist in extension of the humerus

what is the innervation of subscapularis?

upper and lower subscapular nerve (C5, C6, C7)

what is the blood supply for subscapularis?

lateral thoracic and subscapular arteries

what is the main vessel that distributes blood to the upper extremity?

subclavian artery

what are the branches off the subclavian artery?

vertebral

internal thoracic

thyrocervical trunk: suprascapular, transverse cervical → dorsal scapular, inferior thyroid

what artery branches off the 1st part of the axillary artery?

superior thoracic

which arteries branch off the 2nd part of the axillary artery?

thoracoacromial

lateral thoracic

which arteries branch off the 3rd part of the axillary artery?

subscapular → circumflex scapular, thoracodorsal

anterior humeral circumflex

posterior humeral circumflex

what are the borders of the quadrangular space?

superior: subscapularus/teres minor

inferior: teres major

medial: long head of the triceps

lateral: humerus

what are the contents of the quadrangular space?

posterior humeral circumflex artery

axillary nerve

where is the interval triangle located?

medial to the shaft of the humerus and distal to teres major tendon

what are the contents of the interval triangle?

radial nerve

profunda brachial artery

where is the triangular space located?

medial to the quadrangular space and the triceps long head

what are the contents of the triangular space?

circumflex scapular branch of the subscapular artery