Superficial Muscles of the Back

Question 1

trapezius origin

Answer 1

external occipital protuberance, medial 1/3 of super nuchal line, ligamentum nuchae, and SPs of C7-T12

Question 2

trapezius insertion superior fibers

Answer 2

lateral 1/3 of clavicle

Question 3

trapezius insertion middle fibers

Answer 3

acromion and spine of scapula

Question 4

trapezius insertion inferior fibers

Answer 4

base of spine of scapula

Question 5

innervation of trapezius

Answer 5

accessory cranial nerve and 3rd and 4th ventral rami combine to form subtrapezial plexus

Question 6

blood supply of trapezius

Answer 6

superficial branch of transverse cervical artery

Question 7

action of trapezius?

Answer 7

raise, retract, and rotate scapula

Question 8

lat dorsi origin

Answer 8

SPs of T7-T12, all lumbar vertebrae and sacral vertebrae SPs, and posterior part of iliac crest, and lower 3-4 ribs

Question 9

lat dorsi insertion

Answer 9

crest of lesser tubercle, floor of bicipital groove of humerus

Question 10

innervation of lat dorsi

Answer 10

thoracodorsal nerve

Question 11

blood supply of lat dorsi

Answer 11

thoracodorsal artery

Question 12

action of lat dorsi

Answer 12

extend, medial rotation, adduction of arm

Question 13

what fibers of the trapezius retract the scapula?

Answer 13

middle fibers

Question 14

what fibers of the trapezius depress scapula?

Answer 14

inferior fibers

Question 15

what fibers of the trapezius elevate the scapula and rotate the scapula upwards?

Answer 15

superior

Question 16

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?

Answer 16

lat dorsi

Question 17

in what muscle does the superior 1/3 lie deep the the SCM and the inferior 2/3 lie deep to the trap?

Answer 17

lev scap

Question 18

origin of lev scap?

Answer 18

post tubercles of TPs of C1/3/4

Question 19

insertion of lev scap?

Answer 19

medial border of scap from superior angle to ROSOS

Question 20

innervation of lev scap?

Answer 20

ventral rami C3/4 from deep branches of cervical plexus and twig from dorsal scapular nerve C5

Question 21

blood supply of levator scapulae?

Answer 21

deep branch of transverse cervical artery

Question 22

action of levator scapulae?

Answer 22

elevate and retract scapula with trapezius, laterally flex cervical vertebral column when scapula is fixed

Question 23

what two muscles lie deep to trapezius?

Answer 23

r minor and major

Question 24

r minor and r major act together to perform what action?

Answer 24

retract scapula and rotate it to depress glenoid fossa

Question 25

r minor origin?

Answer 25

lower part of lig nuchae and SPs of C7 and T1

Question 26

insertion of r minor?

Answer 26

medial border of scapula at ROSOS

Question 27

innervation of r minor?

Answer 27

dorsal scapular nerve C4/5

Question 28

r minor blood supply?

Answer 28

deep branch of transverse cervical artery

Question 29

action of r minor?

Answer 29

elevate medial border of scapula, retract scapula, and downwards rotation of scapula

Question 30

r major origin?

Answer 30

SPs of T2-5

Question 31

insertion of r major?

Answer 31

medial border of scapula between ROSOS and inferior angle

Question 32

innervation of r major?

Answer 32

dorsal scapular nerve C4/5

Question 33

dorsal scapular nerve?

Answer 33

C4/5

Question 34

r major blood supply?

Answer 34

deep branch of transverse cervical artery

Question 35

action of r major?

Answer 35

elevate medial border of scapula, retract scapula, and downward rotation of scapula

Question 36

what is the triangle of auscultation?

Answer 36

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

Question 37

aponeurosis

Answer 37

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

Question 38

thoracolumbar aponeurosis

Answer 38

thin, transparent fascia in thoracic region. thick, strong fibrous CT that contains fibroblasts in lumbar. blends laterally with aponeurosis of TVA in lumbar region

Question 39

anterior layer of thoracolumbar aponeurosis?

Answer 39

anterior to QL. ends medially in TP of LV. combines laterally with aponeurosis of TVA.

Question 40

middle layer of TCA?

Answer 40

posterior to QL and attaches to TP. anterior to intrinsic muscles of back.

Question 41

posterior layer of TCA?

Answer 41

covers erector spinae group. ends laterally in lumbar by blending with aponeurosis of TVA.

Question 42

principal actions of superficial muscles of the back?

Answer 42

motions of the upper limb