Extrinsic Back Muscles

Question 1

superficial muscles insertion

Answer 1

pectoral girdle or arm

Question 2

superficial muscles innervation

Answer 2

cranial nerve, spinal nerve via plexus

Question 3

intermediate muscles innervation

Answer 3

spinal nerve, anterior ramus

Question 4

deep muscles insertion

Answer 4

vertebra, skull, proximal rib

Question 5

deep muscles innervation

Answer 5

spinal nerve, posterior ramus

Question 6

which level of muscles is anterior ramus?

Answer 6

intermediate

Question 7

which level of muscles is posterior ramus?

Answer 7

deep

Question 8

5 types of superficial extrinsic back muscles

Answer 8

• trapezius
• latissimus dorsi
• levator scapulae
• rhomboid major
• rhomboid minor

Question 9

ascending and descending fibers of trapezius causes what action

Answer 9

upward rotation of the scapula

Question 10

trapezius origin

Answer 10

• superior nuchal line
• external occipital protuberance
• nuchal ligament
• SP lower cervical, upper thoracic

Question 11

trapezius insertion

Answer 11

• lateral 1/3 of clavicle
• acromion process
• spine of scapula

Question 12

trapezius action

Answer 12

• descending fibers = elevation
• middle fibers = retraction
• ascending fibers = depression
• ascending and descending fibers together = upward rotation of the scapula
• extension of head and neck

Question 13

trapezius innervation

Answer 13

motor = accessory nerve (11)

sensory = anterior rami of mid cervical

Question 14

trapezius blood supply

Answer 14

superficial branch of transverse cervical artery

Question 15

what is a high area for injury by physicans?

Answer 15

between the sternocleidomastoid and trapezius where the accessory nerve is superficial and vulnerable

Question 16

levator scapulae origin

Answer 16

TP upper cervical

Question 17

levator scapulae insertion

Answer 17

superior angle of scapula

Question 18

levator scapulae action

Answer 18

elevation and downward rotation of scapula

**lateral flexion of the neck = when contraction of the muscle when the shoulder is fixed

Question 19

levator scapulae innervation

Answer 19

motor = dorsal scapular nerve

sensory = anterior rami mid cervical

Question 20

levator scapulae blood supply

Answer 20

-dorsal scapular artery (deep branch of transverse cervical artery)

Question 21

rhomboid major origin

Answer 21

• nuchal ligament
• supraspinatous ligament
• SP upper thoracic

Question 22

rhomboid major insertion

Answer 22

medial border of scapula inferior to spine

Question 23

rhomboid major action

Answer 23

retraction and downward rotation of scapula

Question 24

rhomboid major innervation

Answer 24

dorsal scapular nerve (C5)

Question 25

rhomboid major blood supply

Answer 25

dorsal scapular artery (deep branch of transverse cervical artery)

Question 26

rhomboid minor origin

Answer 26

- nuchal ligament - supraspinatous ligament - SP lower cervical, upper thoracic

Question 27

rhomboid minor insertion

Answer 27

medial border of the root of spine of scapula

Question 28

rhomboid minor innervation

Answer 28

dorsal scapular nerve (C5)

Question 29

rhomboid minor blood supply

Answer 29

dorsal scapular artery (deep branch of transverse cervical artery)

Question 30

latissimus dorsi origin

Answer 30

- SP lower thoracic - ribs 9-12 - thoracolumbar fascia - iliac crest

Question 31

latissimus dorsi insertion

Answer 31

floor of intertubercular sulcus on anterior humerus

Question 32

rhomboid major action

Answer 32

-fixes scapula to thoracic wall -retracts and rotates scapula to depress glenoid cavity

Question 33

rhomboid minor action

Answer 33

-fixes scapula to thoracic wall -retracts and rotates scapula to depress glenoid cavity

Question 34

latissimus dorsi action

Answer 34

- extends humerus - adducts humerus - medially rotates humerus

Question 35

latissimus dorsi innervation

Answer 35

motor = thoracodorsal nerve (posterior cord C6-C8)

Question 36

latissimus dorsi blood supply

Answer 36

thoracodorsal artery

Question 37

2 intermediate extrinsic back muscles

Answer 37

- serratus posterior superior | - serratus posterior inferior

Question 38

serratus posterior superior origin

Answer 38

- nuchal ligament | - SP lower cervical, upper thoracic

Question 39

serratus posterior superior insertion

Answer 39

dital angle ribs 2-5

Question 40

serratus posterior superior action

Answer 40

elevates ribs 2-5

Question 41

serratus posterior superior innervation

Answer 41

anterior rami T2-T5 (intercostal nerves)

Question 42

serratus posterior superior blood supply

Answer 42

posterior intercostal arteries

Question 43

serratus posterior inferior origin

Answer 43

SP lower thoracic, upper lumbar

Question 44

serratus posterior inferior insertion

Answer 44

distal angle ribs 9-12

Question 45

serratus posterior inferior action

Answer 45

depresses ribs 9-12

Question 46

serratus posterior inferior innervation

Answer 46

intercostal nerves - anterior rami T9-T11 subcostal nerves - anterior rami T12

Question 47

serratus posterior inferior blood supply

Answer 47

posterior intercostal arteries

Question 48

If the cross section image of the back has a scapula, what is the most superficial muscle?

Answer 48

trapezius

Question 49

If the cross section image of the back DOES NOT have a scapula, what is the most superficial muscle?

Answer 49

latissimus dorsi

Question 50

From the lower thoracic to the lumbar levels, the posterior cutaneous branch originates from the _____ branches of the posterior rami and enters the superficial fascia lateral to the thoracolumbar fascia.

Answer 50

lateral

Question 51

map out the dorsal branch of the posterior intercostal artery

Answer 51

descending aorta >> course along thoracic wall in the intercostal spaces >> posterior intercostals give rise to the deep branch

Question 52

what does the dorsal branch of the posterior intercostal artery course with?

Answer 52

posterior ramus

Question 53

what is the venous drainage for the extrinsic back muscles

Answer 53

- intercostal veins - azygos vein - superior vena cava - inferior vena cava

Question 54

triangle of auscultation

Answer 54

- medial wall = inferior margin of trapezius - lateral wall = medial border of scapula - inferior wall = superior margin of latissimus dorsi - floor = 6th and 7th rib, external intercostal within 6th intercostal space

Question 55

which muscle is most likely involved in elevating, depressing, and retracting the scapula?

Answer 55

trapezius

Question 56

what nerve is injured if movements involving adduction, medial rotation, and extension of the arm are weak?

Answer 56

thoracodorsal

Question 57

severed transverse cervical artery would affect which muscle most?

Answer 57

trapezius

Question 58

severed posterolateral aspect of neck causes inability to elevate tip of shoulder on the injured side, what nerve is injured?

Answer 58

accessory