Unit 1 Exam Intrinsic Back

Question 1

Splenius capitis muscle

Answer 1

proximal attachment: nuchal ligament, spinous processes of lower cervical and upper thoracic vertebrae

distal attachment: superior nuchal line, mastoid process

primary actions:
unilaterally: laterally flex head and neck, ipsilateral rotation
bilaterally: extend head and neck

innervations: posterior rami in region of the muscle

Question 2

Splenius cervicis muscle

Answer 2

proximal attachment: spinous processes of upper thoracic vertebrae

distal attachment: transverse processes of upper cervical vertebrae

primary actions:
unilaterally: laterally flex the neck, ipsilateral rotation
bilaterally: extend neck

innervations: posterior rami in region of the muscle

Question 3

Iliocostalis muscles

Answer 3

proximal attachment: sacrum, iliac crest, spinous processes in lumbar region

distal attachment: ribs

primary actions:
unilaterally: laterally flex
bilaterally: extend

innervations: posterior rami in region of the muscle

Question 4

Longissimus muscles

Answer 4

proximal attachment: sacrum, iliac crest, spinous processes in lumbar region, transverse processes

distal attachment: transverse processes, ribs

primary actions:
unilaterally: laterally flex
bilaterally: extend

innervations: posterior rami in region of the muscle

Question 5

Longissimus capitis muscle

Answer 5

proximal attachment: transverse processes in upper thoracic and lower cervical

distal attachment: mastoid process

primary actions:
unilaterally: laterally flex, ipsilateral rotation
bilaterally: extend

innervations: posterior rami in region of the muscle

Question 6

spinalis muscles

Answer 6

proximal attachment: spinous processes

distal attachment: spinous processes

primary actions:
bilaterally: extend

innervations: posterior rami in region of the muscle

Question 7

semispinalis muscles (spans 5-6 vertebrae)

Answer 7

proximal attachment: transverse processes of thoracic and cervical regions

distal attachment: spinous processes of thoracic & cervical regions

primary actions:
unilaterally: contralateral rotation
bilaterally: extension

innervations: posterior rami in region of the muscle

Question 8

semispinalis capitis muscle (spans 5-6 vertebrae)

Answer 8

proximal attachment: transverse processes of thoracic & cervical region

distal attachment: between superior and inferior nuchal lines

primary actions:
unilaterally: contralateral rotation
bilaterally: extension

innervations: posterior rami in region of the muscle

Question 9

Multifidus muscle (spans 3-4 vertebrae, most prominent in lumbar region)

Answer 9

proximal attachment: sacrum, PSIS, mammillary processes of lumbar vertebrae, transverse processes of thoracic & cervical vertebrae

distal attachment: spinous processes

primary actions: stabilize, extend, contralateral rotation of vertebrae

innervations: posterior rami in region of the muscle

Question 10

Rotatores muscles (spans 1-2 vertebrae, most prominent in thoracic region)

Answer 10

proximal attachment: transverse processes

distal attachment: spinous processes or lamina

primary actions: stabilize, extend, contralateral rotation of vertebrae

innervations: posterior rami in region of the muscle

Question 11

Levatores costarum muscles

Answer 11

proximal attachment: transverse processes

distal attachment: ribs

primary actions: elevate ribs

innervations: posterior rami in region of the muscle

Question 12

Interspinales muscles

Answer 12

proximal attachment: spinous process

distal attachment: spinous process

primary actions: stabilize

innervations: posterior rami in region of the muscle

Question 13

Intertransversarii muscles

Answer 13

proximal attachment: transverse process

distal attachment: transverse process

primary actions: stabilize

innervations: posterior rami in region of the muscle

Question 14

rectus capitis posterior major muscle

Answer 14

proximal attachment: spinous process C2

distal attachment: inferior nuchal line

primary actions: extension of head, ipsilateral rotation

innervations: suboccipital n (posterior ramus C1)

Question 15

rectus capitis posterior minor muscle

Answer 15

proximal attachment: posterior tubercle C1

distal attachment: inferior nuchal line

primary actions: extension of head, ipsilateral rotation

innervations: suboccipital n (posterior ramus C1)

Question 16

Obliquus capitis superior muscle

Answer 16

proximal attachment: transverse process C1

distal attachment: between superior & inferior nuchal lines

primary actions: extension, lateral flexion of head

innervations: suboccipital n (posterior ramus C1)

Question 17

Obliquus capitis inferior muscle

Answer 17

proximal attachment: spinous process C2

distal attachment: transverse process C1

primary actions: ipsilateral rotation of head

innervation: suboccipital n (posterior ramus C1)