major deep layers of the back

Question 1

semispinalis origin

Answer 1

transverse processes of C4-T12

Question 2

semispinalis insertion

Answer 2

capitis: back of skill between nuchal lines

cervicis & thoracis: spines 4-6 vertebrae above origin

Question 3

semispinalis action

Answer 3

bilateral contraction = extends the trunk and neck

unilateral contraction = rotates the trunk and head to the opposite side

Question 4

semispinalis/multifidus/rotatores innervation

Answer 4

dorsal primary rami of spinal nerves

Question 5

semispinalis arteries

Answer 5

supplied segmentally

cervical = occipital, deep cervical, vertebral

thoracic = posterior intercostal arteries, subcostal arteries

lumbar = lumbar arteries

Question 6

multifidus origin

Answer 6

1. articular processes of C4-7
2. transverse processes of T1-T12
3. sacrum
4. ilium

Question 7

multifidus insertion

Answer 7

spinous processes 2-4 vertebral levels superior to their origin

Question 8

multifidus action

Answer 8

bilateral contraction = extends the trunk

unilateral contraction = rotates the trunk to the opposite side, stabilizes spine

Question 9

multifidus artery

Answer 9

supplied segmentally:
1. cervical= occipital, deep cervical a. and vertebral a,

2. thoracic = posterior intercostal aa., subcostal a., lumbar aa.
3. lumbar = lateral sacral a.

Question 10

rotatores origin

Answer 10

transverse processses

Question 11

rotatores insertion

Answer 11

longus = spinour provesses 2 vertebrae above origin

brevis = spinous processes 1 vertebrae above origin

Question 12

rotatores action

Answer 12

bilateral contraction = stabilize and extend spine

unilateral contraction = rotate the vertebral column contralaterally

Question 13

rotatores arteries

Answer 13

supplied segmentally:

cervical : deep cervical a.,

thoracic : posterior intercostal aa., subcostal a.,

lumbar : lumbar aa.