Extrinsic Back Musculature

Question 1

Extrinsic musculature consists of ______ and _____ layers of the back

Answer 1

Extrinsic musculature consists of superficial and intermediate layers of the back

Question 2

Extrinsic musculature innervated by ______ and develop (ventrally/dorsally)

Answer 2

Extrinsic musculature innervated by ventral rami (except trapezius) and develop ventrally

Question 3

Superficial Extrinsic Back Muscles (Axio-Appendicular Musculature): List the (5)

Answer 3

1. Trapezius
2. Latissimus dorsi
3. Levator Scapulae
4. Rhomboid minor
5. Rhomboid major

Question 4

Identify this muscle

Answer 4

Trapezius

Question 5

Insertion:

Action:

Innervation:

Answer 5

Trapezius

Insertion: acromion and spine of the
scapula

Action:
o Upper fibers (descending): Elevate scapula
o Middle fibers: Retract scapula
o Lower fibers (ascending): Depress scapula
o Upper + Lower: superior rotation of shoulder joint (glenohumeral joint)

Innervation: Spinal accessory nerve (Cranial Nerve XI)

Question 6

Trapezius action

Answer 6

1. Descending: elevation of scapula
2. Middle: retracts scapula
3. Ascending: depresses scapula
4. Descending + ascending: superior rotation of shoulder joint (glenohumeral joint)

Question 7

Trapezius innervation

Answer 7

CN XI: Spinal Accessory Nerve.

Question 8

Identify this muscle

Answer 8

Latissimus Dorsi

Question 9

Origin:
Insertion:
Action:
Innervation:

Answer 9

Latissimus Dorsi

Origin: Spinous processes of T6-T12, thoracolumbar fascia, iliac crest

Insertion: Intertubercular sulcus of the humerus

Action: Arm extension, adduction, and medial rotation of the humerus at the glenohumeral joint

Innervation: Thoracodorsal nerve (C6-C8) ventral rami

Question 10

Latissimus dorsi action

Answer 10

extends, adducts, and medially rotates the humerus at the glenohumeral joint

Question 11

Lastissimus dorsi innervation

Answer 11

Thoracodorsal nerve

Question 12

Levator Scapulae
Origin:
Insertion:
Action:
Innervation:

Answer 12

Origin: Transverse processes of C1-C4

Insertion: Medial border of the scapula (superior to the root of scapular spine)

Action: Elevates the scapula, assists in downward rotation;

Innervation: Dorsal scapular nerve (C5) ventral rami

Question 13

Identify this muscle

Answer 13

Levator scapulae

Question 14

Levator scapulae action

Answer 14

Elevates scapula rotates
glenoid cavity inferiorly

Question 15

Levator scapulae innervation

Answer 15

Dorsal scapular nerve (C5) of ventral rami

Question 16

Origin:
Insertion:
Action:
Innervation:

Answer 16

Levator Scapulae

Origin: Transverse processes of C1-C4

Insertion: Medial border of the scapula (superior to the root of scapular spine)

Action: Elevates scapula rotates
glenoid cavity inferiorly

Innervation: Dorsal scapular nerve (C5) ventral rami

Question 17

Origin:
Insertion:
Action:
Innervation:

Answer 17

Rhomboid Minor

Origin: Spinous processes of C7-T1 + nuchal ligament

Insertion: Medial end of scapula, at the level of the spine

Action: Retracts and stabilizes the scapula to the thoracic wall; inferior rotation of the glenohumeral joint

Innervation: Dorsal scapular nerve (C5) ventral rami

Question 18

Identify this muscle

Answer 18

Rhomboid minor

Question 19

Rhomboid minor and major innervation

Answer 19

Dorsal scapular nerve (C5) ventral rami

Question 20

scapula translated laterally and downwardly rotated.

Answer 20

Trapezius palsy: “drooped shoulder”

scapula translated laterally and downwardly rotated.

Question 21

Describe Trapezius palsy treatment:

Answer 21

surgically with muscle transfers of levator scapulae and rhomboids

Question 22

scapula moved laterally and lower medial border and inferior angle are raised

Answer 22

RHOMBOID PALSY:
scapula moved laterally and lower medial border and inferior angle are raised

Question 23

TREATMENT FOR?

Answer 23

TRAPEZIUS PALSY TREATMENT: levator scapulae is moved to the scapular spine, rhomboids moved to the posterior inferior scapula.

Question 24

Nerves of the back:

Answer 24

1. Spinal Accessory Nerve - CN XI
2. Dorsal scapular nerve (C5)
3. Thoracodorsal nerve (C6-C8)
4. Cutaneous branches of posterior rami

Question 25

Dermatomes of the back

Answer 25

Question 26

Identify this muscle

Answer 26

rhomboid major

Question 27

Origin:
Insertion:
Action:
Innervation:

Answer 27

Origin: Spinous processes of T2-T5

Insertion: Medial border of the scapula (below the spine)

Action: Retracts and stabilizes the scapula to the thoracic wall; inferior rotation of the glenohumeral joint

Innervation: Dorsal scapular nerve (C5) ventral rami

Question 28

Provides cutaneous branches of posterior rami

Answer 28

posterior rami

Question 29

A ______ is a unilateral strip of skin innervated by the sensory (GSA) fibers of a single spinal nerve

Answer 29

Dermatome

Question 30

Which nerve travels from the cranium through the neck and back deep to trapezius?

Answer 30

Spinal Accessory Nerve (CN XI)

Question 31

Which nerve innervates the rhomboid major and rhomboid minor?

Answer 31

Dorsal scapular nerve

Question 32

Which nerve emerges anteriorly, travels over the middle scalene (neck muscles) before moving posteriorly deep to levator scapulae and the rhomboids

Answer 32

Dorsal scapular nerve

Question 33

Dorsal scapular nerve is C”x”

Answer 33

C5

Question 34

Thoracodorsal nerve is C”x”-C”x”

Answer 34

C6-C8; posterior brachial plexus

Question 35

The dorsal scapular nerve supplies which (3) muscles?

Answer 35

1. Rhomboid major
2. Rhomboid minor
3. Levator scapulae