Back Muscles Flashcards
how are the muscles of the back organized?
extrinsic and intrinsic
what is the purpose of the extrinsic muscles? Intermediate muscles?
extrinsic - movement of the upper extremity
intermediate - assist in breathing
what are the superficial extrinsic muscles?
trapezius
latissimus dorsi
rhomboideus minor / major
levator scapulae
what innervates the extrinsic muscles?
branches of the ventral rami
what are the origins of the trapezius?
superior nuchal line
spinous process of cervical and thoracic vertebrae
where does the trapezius insert?
acromion of scapula
anterior portion of clavicle
spine of the scapula
what action does the upper division of the trapezius allow for?
elevation of scapula
retraction of glenoid fossa superiorly
retraction of scapula
lateral flexion of head
what action does the middle division of the trapezius allow for?
retraction of scapula
what action does the lower division of the trapezius allow for?
depression of scapula
assists in rotation of scapula
what occurs when the upper and lower divisions of the trapezius are contracted?
rotation of scapula by elevating glenoid fossa
rotation allows for upper extremity to abduct and reach.
what nerve supplies the trapezius?
Cranial Nerve XI / spinal accessory nerve
what is the cranial nerve xi / accessory nerve?
joining of fibers from cranial nerve x and segments of C3,4
what is the arterial supply of the trapezius?
superficial branch of the transverse cervical artery
what is the test to see if there is innervation or muscle damage for the trapezius?
shrugging of shoulders against resistance
what does the trapezius’s name mean?
irregular
what does the latissimus dorsi’s name mean?
widest
where does the latissimus dorsi originate? where does it insert?
thoracolumbar fascia at TV6 to LV5 and iliac crest to the intertubercular groove of humerus
where does the latissimus dorsi extend to?
intertubercular groove of the humerus
what actions does the latissimus dorsi allow?
IR of humerus
adduction of humerus
extension of humerus
what nerve supplies the latissimus dorsi?
thoracodorsal nerve at C6,7,8
what artery supplies the latissimus dorsi?
thoracodorsal branch of axillary artery
what is the test for the latissimus dorsi?
pull up
where does the levator scapulae attach?
from transverse processes of CV1-4 to the medial border of the scapula
what nerve innervates the levator scapulae?
Cranial nerves 3&4 / dorsal scapular
what artery supplies the levator scapulae?
transverse cervical artery
what action does the levator scapulae permit?
elevation of scapula
where does the rhomboid major attach?
from spinous process of TV2-TV5 to medial border of scapula inferior to spine