Superficial Muscles Of The Back

Front 1

Trapezius Origin

Back 1

Origin: Medial third of superior nuchal line, external occipital protuberance, ligamentum nuchae, T1-T12 spinous process

Front 2

Trapezius Insertion

Back 2

Insertion: Spine of scapula, acromion, lateral third of clavicle

Front 3

Trapezius Action

Back 3

Actions: Elevates and retracts pectoral girdle, superiorly rotates scapula

Front 4

Trapezius Innervation

Back 4

Innervation: Spinal accessory nerves (CN XI)→ motor

C3-C4 ventral rami via cervical plexus→sensory (pain, proprioception)

Front 5

Trapezius Blood Supply

Back 5

Blood Supply: Transverse cervical artery

Front 6

Trapezius denervation results in:

Back 6

Drooping of the affected shoulder, lateral winging of the scapula. Ability to abduct arm above shoulder level may be significantly impaired.

Front 7

Latissimus Dorsi Origin

Back 7

Origin: T7-L5 spinous processes, thoracolumbar fascia, dorsal sacrum, iliac crest

Front 8

Latissimus Dorsi Insertion

Back 8

Insertion: Floor of intertubercular sulcus of humerus

Front 9

Latissimus Dorsi Actions

Back 9

Actions: Extends, adducts, and medially rotates humerus (Depresses, retracts, and inferiorly rotates scapula)

Front 10

Latissimus Dorsi Innervation

Back 10

Innervation: Thoracodorsal n.

Front 11

Latissimus Dorsi Blood Supply

Back 11

Blood Supply: Thoracodorsal a.

Front 12

Latissimus Dorsi Functional Correlation:

Back 12

Functional Correlation: When the upper extremity is fixed, the latissimus dorsi m. forcefully pulls
the torso anteriorly and superiorly. This capability is exploited by gymnasts, swimmers, rock
climbers, and people walking with crutches.

Front 13

Rhomboideus major m. Origin

Back 13

Origin: T2-T5 spinous processes

Front 14

Rhomboideus major m. Insertion

Back 14

Insertion: Medial border of scapula

Front 15

Rhomboideus major m. Actions

Back 15

Actions: Retracts and elevates pectoral girdle, inferiorly rotates scapula

Front 16

Rhomboideus major m. Innervation

Back 16

Innervation: Dorsal scapular n.

Front 17

Rhomboideus major m. Blood Supply

Back 17

Blood Supply: Dorsal scapular a.

Front 18

Rhomboideus minor m. Origin

Back 18

Origin: C7-T1 spinous processes

Front 19

Rhomboideus minor m. Insertion

Back 19

Insertion: Medial border of scapula superior to rhomboideus major m.

Front 20

Rhomboideus minor m. Actions

Back 20

Actions: Retracts and elevates pectoral girdle, inferiorly rotates scapula

Front 21

Rhomboideus minor m. Innervation

Back 21

Innervation: Dorsal scapular n. (C5)

Front 22

Rhomboideus minor m. Blood Supply

Back 22

Blood Supply: Dorsal scapular a.

Front 23

Levator scapulae m. Origin

Back 23

Origin: Separate slips from posterior tubercles of C1-C4 transverse processes

Front 24

Levator scapulae m. Insertion

Back 24

Insertion: Superior angle of scapula

Front 25

Levator scapulae m. Actions

Back 25

Actions: Protracts and elevates pectoral girdle, inferiorly rotates scapula

Front 26

Levator scapulae m. Innervation

Back 26

Innervation: C3-C4 ventral rami via cervical plexus and dorsal scapular n. (C5)

Front 27

Levator scapulae m. Blood Supply

Back 27

Blood Supply: Dorsal scapular a.

Front 28

Serratus posterior superior m. Origin

Back 28

Origin: C7-T3 spinous processes

Front 29

Serratus posterior superior m. Insertion

Back 29

Insertion: Superior borders of ribs 2-5

Front 30

Serratus posterior superior m. Actions

Back 30

Actions: Elevates (weakly) ribs 2-5

Front 31

Serratus posterior superior m. Innervation

Back 31

Innervation: Segmentally by ventral primary rami (intercostal nerves)

Front 32

Serratus posterior superior m. Blood Supply

Back 32

Blood Supply: Branches of posterior intercostal aa.

Front 33

Serratus posterior inferior m. Origin

Back 33

Origin: T11-L3 spinous processes

Front 34

Serratus posterior inferior m. Insertion

Back 34

Insertion: Inferior borders of ribs 9-12

Front 35

Serratus posterior inferior m. Actions

Back 35

Actions: Depresses (weakly) ribs 9-12

Front 36

Serratus posterior inferior m. Innervation

Back 36

Innervation: Segmentally by ventral primary rami (intercostal nn.)

Front 37

Serratus posterior inferior m. Blood Supply

Back 37

Blood Supply: Branches of posterior intercostal aa.

Front 38

Serratus posterior superior and inferior mm Functional Correlation

Back 38

Functional Correlation: By virtue of their insertions on ribs, serratus posterior superior and inferior
are considered accessory muscles of respiration. Their ability to effect movements of the thoracic
cage is obviously minimal.

Front 39

Skin of the central back (overlying the intrinsic muscles) innervation:

Back 39

Innervation: segmentally by
posterior cutaneous nerves, which are branches of dorsal primary rami.

Front 40

Skin of the lateral back innervation:

Back 40

Innervation: segmentally by lateral cutaneous nerves, which are
branches of ventral primary rami.

Front 41

Skin of the back blood supply:

Back 41

branches of posterior and lateral cutaneous arteries, which are branches of the segmental arteries of the trunk.

Front 42

Superficial muscles blood supply:

Back 42

subclavian and axillary aa.

Front 43

Transverse cervical a.:

Back 43

from the thyrocervical trunk off the subclavian a.

Courses posteriorly in the neck superficial to levator scapulae m.

Passes deep to trapezius m. giving ascending and descending branches.

Front 44

Dorsal scapular a.:

Back 44

arises as a branch of the transverse cervical artery (50%) or a direct
branch of the subclavian a. (50%) and courses with the dorsal scapular n.

Courses posteriorly in the neck deep to levator scapulae m.

Descends deep to rhomboideus major and minor mm.

Front 45

Thoracodorsal a.:

Back 45

from the subscapular a. (a branch of the axillary a.); courses with the
thoracodorsal n. deep to latissimus dorsi m.

Front 46

Lymph from the dorsal neck and upper back drains to:

Back 46

cervical and axillary lymph nodes.

Front 47

Lymph from the lower back (flank) drains to:

Back 47

inguinal lymph nodes.