Back Muscles

Question 1

trunk intrinsic muscles

Answer 1

act primarily on the spine (usually deeper)

Question 2

trunk extrinsic muscles

Answer 2

act on the upper limb or as respiratory muscles (more superficial)

Question 3

superficial posterior extrinsics

Answer 3

trapezius
lattisimus dorsi
rhomboids (major and minor)
levator scapula

Question 4

intermediate extrinsics

Answer 4

serratus posterior super
serratus posterior inferior

Question 5

serratus posterior superior action

Answer 5

proprioceptive; may elevate ribs

Question 6

serratus posterior inferior action

Answer 6

proprioceptive; may depress ribs

Question 7

superior anterior extrinsic

Answer 7

pectoralis major
pectoralis minor
serratus anterior

Question 8

intercostal muscles

Answer 8

external intercostals
internal intercostals
innermost intercostals
subcostals
transverse thoracis
levator costarum

Question 9

neurovascular supply to intercostals

Answer 9

between the internal and innermost layers of the intercostals in the costal groove
innervation: segmental APRs

Question 10

superficial intrinsic

Answer 10

splenius cervicis
splenius capitus

Question 11

splenius capitus action

Answer 11

lateral flexion
ipsilateral rotation
bilateral extension

Question 12

splenius cervicis action

Answer 12

lateral flexion
ipsilateral rotation
bilateral extension

Question 13

intermediate intrinsic: errector spinae

Answer 13

arise from a common aponeurotic origin part of the thoracolumbar fascia that attaches to the iliac crest, sacrum, sacroiliac ligaments and inferior lumbar and sacral spinous processes

Question 14

iliocostalis

Answer 14

inserts into the angle of the ribs

Question 15

longissimus

Answer 15

inserts into the tips of the thoracic transverse processes

Question 16

spinalis

Answer 16

insert into the thoracic spinous processes and superior thoracic transverse processes

Question 17

iliocostalis, longissimus, spinalis action

Answer 17

bilateral;
concentrically: extend vertebral column and head against gravity
eccentrically: controls rate of trunk flexion
isometrically: maintains erect posture
unilateral: laterally flex trunk

Question 18

deep intrinsics: transversospinal muscles

Answer 18

semispinalis: 4-6 vertebral segments
multifidus: 2-4 vertebral segments
rotatores: 1-2 vertebral segments

Question 19

semispinalis action

Answer 19

extension
contralateral rotation

Question 20

multifidus action

Answer 20

extension
contralateral rotation
stabilizes

Question 21

rotatores action

Answer 21

contralateral rotation
stabilizes

Question 22

minor deep later

Answer 22

interspinales: between spinal processes
intertransverserii: between transverse processes
levator costarum: transverse process to rib below

Question 23

interspinales action

Answer 23

aide in extension

Question 24

intertransversarii action

Answer 24

aide in lateral flexion
stabilizes

Question 25

levator costarum action

Answer 25

elevate ribs, assist with respiration, assist with lateral flexion

Question 26

thoracolumbar fascia

Answer 26

superficial and deep functional significance of this thick layer of connective tissue is that it confers stability to the lumbar spine