Intrinsic Back Muscles Flashcards Preview

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Flashcards in Intrinsic Back Muscles Deck (33):
1

Splenius origin

arises from nuchal ligament and spinous processes of C7-T6 vertebrae

2

splenius capitis insertion

fibers run superolaterally to mastoid process of temporal bone and lateral third of superior nuchal line of occipital bone

3

splenius cervicis insertion

tubercles of transverse processes of C1-C3 or C4 vertebrae

4

splenius innervation

posterior rami of spinal nerves

5

splenius action

acting alone: laterally flex neck and rotate head to side of active muscles
acting together: extend head and neck

6

superficial layer of intrinsic back muscles

splenius capitis and splenius cervicis

7

intermediate layer of intrinsic back muscles (erector spinae)

iliocostalis, longissimus, spinalis

8

Iliocostalis origin

arises by broad tendon from posterior part of iliac crest, posterior surface of sacrum, sacro-iliac ligaments, sacral and inferior lumbar spinous processes and supraspinous ligament

9

longissimus origin

arises by broad tendon from posterior part of iliac crest, posterior surface of sacrum, sacro-iliac ligaments, sacral and inferior lumbar spinous processes and supraspinous ligament

10

spinalis origin

arises by broad tendon from posterior part of iliac crest, posterior surface of sacrum, sacro-iliac ligaments, sacral and inferior lumbar spinous processes and supraspinous ligament

11

iliocostalis insertion

fibers run superiorly to angles of lower ribs and cervical transverse processes

12

iliocostalis made up of

lumborum, thoracis, and cervicis

13

longissimus insertion

fibers run superiorly to ribs between tubercles and angles to transverse processes in thoracic and cervical regions and to mastoid process of temporal bone

14

longissimus made up of

thoracis, cervicis and capitis

15

spinalis insertion

fibers run superioly to spinous processes in upper thoracic region and to cranium

16

spinalis made up of

thoracis, cervicis, and capitis

17

iliocostalis innervation

posterior rami of spinal nerves

18

longissimus innervation

posterior rami of spinal nerves

19

spinalis innervation

posterior rami of spinal nerves

20

iliocostalis, longissimus, spinalis action

acting bilaterally: extend vertebral column and head, as back is flexed, control movement by gradually lengthening their fibers
acting unilaterally: laterally flex vertebral columns

21

deep layer of intrinsic back muscles (transversospinales)

semispinalis (thoracis, cervicis, and capitis)
multifidus
rotatores (brevis and longus)

22

semispinalis origin

arises from transverse processes of C4- T10 vertebrae

23

semispinalis insertion

fibers run superomedially to occipital bone and spinous processes in upper thoracic and cervical regions, spanning four to six segments

24

semispinalis innervation

posterior rami of spinal nerves

25

semispinalis action

extends head and thoracic and cervical regions of vertebral column and rotate them contralaterally

26

multifidus origin

arises from posterior sacrum, posterior superior iliac spine of ilium, aponeurosis of erector spinae, sacro-iliac ligaments, mammillary processes of lumbar vertebrae, transverse processes of thoracic vertebrae, and articular processes of C4-C7

27

multifidus insertion

thickest in lumbar region, fibers pass obliquely superomedially to entire length of spinous processes of vertebrae located two to four segments superior to origin

28

multifidus innervation

posterior rami of spinal nerves

29

multifidus action

unilateral contraction rotates to contralateral side. stabilizes vertebrae during local movements of vertebral column

30

rotatores origin

arise from transverse processes of vertebrae, are best developed in thoracic region

31

rotatores insertion

fibers pass superomedially to attach to junction of lamina and transverse process or spinous process of vertebra immediately (brevis) or two segments (longus) superior to vertebra of origin

32

rotatores innervation

posterior rami of spinal nerves

33

rotatores action

may function as organs of proprioception, possibly stabilize vertebrae and assist with local extensor and rotatory movements of vertebral column