Extrinsic Superficial Back Muscles

Question 0

trapezius

Answer 0

O: EOP, medial sup nuchal line, nuchal ligament, spinous processes C7-T12
I: lateral clavicle, acromian, spine of scapula
N: motor– spinal accessory (CN XI)
sensory– C3, C4
B: transverse cervical artery
A: sup fibers– elevation
middle fibers– retraction
inf fibers– depress
sup and inf fibers together– upwardly rotate glenoid

Question 1

extrinsic superficial back muscles

Answer 1

trapezius
latissimus dorsi
levator scapulae
rhomboids

Question 2

latissimus dorsi

Answer 2

O: spinous processes of T6-T12, thoracolumbar fascia, iliac crest, inf 3-4 ribs
I: floor of intertubercular sulcus
N: thoracodorsal nerve (C6,C7,C8)
B: thoracodoral artery
A: extends, adducts, and medially rotates humerus; pulls body up when arms fixed overhead

Question 3

levator scapulae

Answer 3

O: post tubercles of transverse processes of C1-C4
I: medial border of scapula sup to root of spine
N: dorsal scapular nerve (C5), C3, and C4
A: elevates scapula, downwardly rotates glenoid

Question 4

rhomboid minor

Answer 4

O: nuchal ligament, spinous processes C7, T1
I: med border of scapula at root of spina
N: dorsal scapular nerve (C5)
A: retracts scapula, downwardly rotates glenoid, fix to thoracic wall

Question 5

rhomboid major

Answer 5

O: spinous processes of T2-T5
I: med border of scapula inf to spine
N: dorsal scapular nerve (C5)
A: retracts scapula, downwardly rotates glenoid