Musculature of the Back and Neck

Question 1

what are the 2 major groups of back muscles

Answer 1

extrinsic and intrinsic

Question 2

explain extrinsic muscles

Answer 2

superficial and intermediate muscles that produce and control limb and respiratory movements

Question 3

explain intrinsic muscles

Answer 3

muscles that specifically act on the vertebral column

produces movements and maintain posture

Question 4

extrinsic muscles that connect the upper limbs to the trunk

Answer 4

traps

latissimus dorsi

levator scapulae

rhomboid major and minor

Question 5

intermediate (extrinsic) muscles

Answer 5

serratus posterior superior

serratus posterior inferior

Question 6

serratus posterior posterior

Answer 6

origin: ligamentum nuche, spinous proccesses C7-T3

insertion: superior borders ribs 2-4

innervation: 2nd-5th intercostal nerves

action: elevate ribs

Question 7

serratus posterior inferior

Answer 7

origin: spinous processes T11-L2

insertion: inferior borders ribs 8-12

innervation: ventral rami T9-T12 spinal nerves

action: depresses ribs

Question 8

what is the nerve rule of the deep (intrinsic) muscles

Answer 8

all innervated by the dorsal rami of the spinal nerves

Question 9

what are the layers of the deep (intrinsic) muscles

Answer 9

superficial

intermediate

deep

minor deep

Question 10

what are the muscles in the superficial deep layer

Answer 10

splenius capitis

splenius cervicis

Question 11

splenius capitis

Answer 11

innervation: dorsal rami of the spinal nerves

action: unilateral –> flexes and rotates head to the same side

bilateral–> extends cervical spine and head

Question 12

splenius cervicis

Answer 12

innervation: dorsal rami of the spinal nerves

action: unilateral –> flexes and rotates head to the same side

bilateral –> extends cervical spine and head

Question 13

muscles of the intermediate (deep) muscles

Answer 13

errector spinae (3 parts)

-iliocostalis
-longissimus
-spinalis

all rotate to the same side

Question 14

iliocostalis

Answer 14

innervation: dorsal rami of the spinal nerves

action: unilateral –> bends spine laterally to the same side

bilateral–> extends the spine

Question 15

longissimus

Answer 15

innervation: dorsal rami of the spinal nerve

action: unilateral –> head rotation and neck flexion to same side

bilateral –> head and vertebral column extension

Question 16

spinalis

Answer 16

innervation: dorsal rami of the spinal nerves

action: unilateral –> bends cervical and thoracic spine to same side

bilateral –> extends cervical and thoracic spine

Question 17

what are the muscles in the deep layer of the intrinsic muscles

Answer 17

transverospinalis (3 parts)

-semispinalis
-multifidus
-rotatores

Question 18

semispinalis

Answer 18

innervation: dorsal rami of the spinal nerves

action: posterior stabilizer

unilateral -> bends head, cervical and thoracic spine to the same side
-rotates head to the opposite side

bilateral –> extends spine

Question 19

multifidus

Answer 19

innervation: dorsal rami of the spinal nerves

action: posterior stabilizer

unilateral: flexes spine to same side
-rotates to opposite side

bilateral –> extends spine

Question 20

rotatores

Answer 20

innervation: dorsal rami of the spinal nerves

action: posture stabilizer

unilateral –> rotates spine to opposite side
bilateral–> extends the thoracic spine

Question 21

what are the muscles in the minor deep layer of the intrinsic muscles

Answer 21

interspinales

intertransversarii

levator costarum

Question 22

interspinales

Answer 22

innervation: dorsal rami of the spinal nerves

action: side in vertebral column extension, rotation to the same side

Question 23

intertransversarii

Answer 23

innervation: dorsal and ventral rami of spinal nerves

action: unilateral –> bends the cervical and same side lumbar spines laterally and to the same side

bilateral –> stabilizes and extends the cervical and lumbar spines

Question 24

levatores costarum

Answer 24

innervation: dorsal rami of C8-T11 spinal nerves

action: unilateral –> bend thoracic spine to same side, rotates to opposire side

bilateral –> extends thoracic spine

Question 25

what are the suboccipital muscles

Answer 25

rectus capitis posterior major

rectus capitis posterior minor

obliquus capitis superior

obliquus capitis inferior

each muscle is a pair, so there are 8 total muscles

Question 26

rectus capitis posterior major

Answer 26

origin: spinous processes of C2

insertion: lateral part of inferior nuchal line of occipital bone

innervation: dorsal ramus of C1 spinal nerve (occipital nerve)

action: unilateral–> head ipsilateral rotation

bilateral –> head extension

Question 27

rectus capitus posterior minor

Answer 27

origin: posterior tubercle C1

insertion: medial part of inferior nuchal line of occipital bone

innervation: sub occipital nerve

action: unilateral–> head ipsilateral rotation

bilateral –> head extension

Question 28

obliquus capitis superior

Answer 28

origin: transverse process C1

insertion: occipital bone (inferior nuchal line, middle third and above rectus capitis posterior major)

innervation: sub occipital nerve

action: unilateral –> tilts head to the same side and rotates the head to the opposite side

bilateral –> head extension

Question 29

obliquus capitis inferior

Answer 29

origin: spinous process C2

insertion: transverse process C1

innervation: sub occipital nerve

action: unilateral –> neck ipsilateral rotation

bilateral –> head extension