Extrinsic Back Muscles - Superficial Layer

Question 1

Trapezius

4O, 3I, 2N, 3A

Answer 1

O: 
\+ medial third of superior nuchal line
\+ EOP
\+ nuchal ligament
\+ spinous processes of C7-C12

I:
+ lateral third of clavicle
+ acromion of scapula
+ spine of scapula

N:
+ spinal accessory nerve (CN XI: Motor fibers)
+ C3+C4 spinal nerves (Pain and proprioceptive fibers)

A:
Descending (superior): Elevates scapula
Ascending (inferior): Depresses scapula
Middle (all together): Retracts scapula, rotate glenoid cavity superiorly

Question 2

Latissumus Dorsi

4O, 1I, 3N, 4A

Answer 2

O:
\+ spinous processes of inferior six thoracic vertebrae
\+ thoracolumbar fascia
\+ Iliac crest
\+ Inferior three or four ribs

I:
+ floor of intertubercular sulcus (groove) of humerus

N:
+ thoracodorsal nerve (C6, C7, C8)

A:
+ extends, adducts, and medially rotates shoulder joint
+ raises body toward arms during climbing

Question 3

Levator scapulae

1O, 1I, 2N, 2A

Answer 3

O:
+ Posterior tubercles of transverse processes of C1-C4 vertebrae

I:
+ Medial border of scapula superior to root of spine

N:
+ Dorsal scapular (C5)
+ Cervical (C3, C4)

A:
+ Elevates scapula
+ rotates glenoid cavity inferiorly

Question 4

Rhomboid minor

2O, 1I, 1N, 3A

Answer 4

O:
+ Nuchal ligament
+ Spinous processes of C7 and T1 vertebrae

I:
+ Triangular area at medial end of scapular spine

N:
+ Dorsal scapular nerve (C4, C5*)

A:
+ Retracts scapula
+ Rotates glenoid cavity inferiorly
+ Fix scapula to thoracic wall

Question 5

Rhomboid major

1O, 1A, 1N, 3A

Answer 5

O:
Spinous processes of T2-T5 vertebrae

I:
Medial border of scapula from level of spine to inferior angle

N:
Dorsal scapular nerve (C4, C5*)

A:
Retracts scapula
Rotates glenoid cavity inferiorly
Fix scapula to thoracic wall