Superficial Muscles of the Back Flashcards
trapezius origin
external occipital protuberance, medial 1/3 of super nuchal line, ligamentum nuchae, and SPs of C7-T12
trapezius insertion superior fibers
lateral 1/3 of clavicle
trapezius insertion middle fibers
acromion and spine of scapula
trapezius insertion inferior fibers
base of spine of scapula
innervation of trapezius
accessory cranial nerve and 3rd and 4th ventral rami combine to form subtrapezial plexus
blood supply of trapezius
superficial branch of transverse cervical artery
action of trapezius?
raise, retract, and rotate scapula
lat dorsi origin
SPs of T7-T12, all lumbar vertebrae and sacral vertebrae SPs, and posterior part of iliac crest, and lower 3-4 ribs
lat dorsi insertion
crest of lesser tubercle, floor of bicipital groove of humerus
innervation of lat dorsi
thoracodorsal nerve
blood supply of lat dorsi
thoracodorsal artery
action of lat dorsi
extend, medial rotation, adduction of arm
what fibers of the trapezius retract the scapula?
middle fibers
what fibers of the trapezius depress scapula?
inferior fibers
what fibers of the trapezius elevate the scapula and rotate the scapula upwards?
superior
which muscle is the large, fan shaped muscle that covers the inferior 1/2 of the back and acts directly on shoulder joint and indirectly on pectoral girdle?
lat dorsi
in what muscle does the superior 1/3 lie deep the the SCM and the inferior 2/3 lie deep to the trap?
lev scap
origin of lev scap?
post tubercles of TPs of C1/3/4
insertion of lev scap?
medial border of scap from superior angle to ROSOS
innervation of lev scap?
ventral rami C3/4 from deep branches of cervical plexus and twig from dorsal scapular nerve C5
blood supply of levator scapulae?
deep branch of transverse cervical artery
action of levator scapulae?
elevate and retract scapula with trapezius, laterally flex cervical vertebral column when scapula is fixed
what two muscles lie deep to trapezius?
r minor and major
r minor and r major act together to perform what action?
retract scapula and rotate it to depress glenoid fossa
r minor origin?
lower part of lig nuchae and SPs of C7 and T1
insertion of r minor?
medial border of scapula at ROSOS
innervation of r minor?
dorsal scapular nerve C4/5
r minor blood supply?
deep branch of transverse cervical artery
action of r minor?
elevate medial border of scapula, retract scapula, and downwards rotation of scapula
r major origin?
SPs of T2-5
insertion of r major?
medial border of scapula between ROSOS and inferior angle
innervation of r major?
dorsal scapular nerve C4/5
dorsal scapular nerve?
C4/5
r major blood supply?
deep branch of transverse cervical artery
action of r major?
elevate medial border of scapula, retract scapula, and downward rotation of scapula
what is the triangle of auscultation?
formed by intersection of lat dorsi, trap, and vertebral border of scapula where r major forms the floor and only a thin tissue covers ribs, making sounds of thorax audible
aponeurosis
flat sheet or ribbon of tendon like tissue that anchors a muscle, takes place of tendon or bone in sheet like muscles having wide area of attachment
thoracolumbar aponeurosis
thin, transparent fascia in thoracic region. thick, strong fibrous CT that contains fibroblasts in lumbar. blends laterally with aponeurosis of TVA in lumbar region
anterior layer of thoracolumbar aponeurosis?
anterior to QL. ends medially in TP of LV. combines laterally with aponeurosis of TVA.
middle layer of TCA?
posterior to QL and attaches to TP. anterior to intrinsic muscles of back.
posterior layer of TCA?
covers erector spinae group. ends laterally in lumbar by blending with aponeurosis of TVA.
principal actions of superficial muscles of the back?
motions of the upper limb
