Spine Muscles

Question 1

Name the superficial muscles of the spine.

Answer 1

Trapezius
Latissimus dorsi
Levator scapulae
Rhomboid major
Rhomboid minor

Extrinsic muscles that provide limb movement

Question 2

Name the intermediate muscles of the spine.

Answer 2

Serratus posterior superior
Serratus posterior inferior

Extrinsic muscles that provide limb movements

Question 3

Name the deep muscles of the spine.

Answer 3

3 layers of deep muscles:

- Superficial: Splenius group
- Intermediate: Erector spinae group
- Deep: Semispinalis, Multifidus, Rotatores

Intrinsic muscles that act specifically on the vertebral column for postural control

Question 4

Describe the origin, insertion, action, and innervation for the trapezius.

Answer 4

O: superior nuchal line, external occipital protuberance, C1-C7 via ligamentum flavum, C7-T12 spinous processes

I: superior edge of scapular spine, acromion process, posterior border of lateral 1/3 of clavicle

N: spinal accessory nerve (CN XI)

A: scapular elevation and lateral rotation, scapular retraction and depression, neck and back extension

Question 5

Describe the origin, insertion, action, and innervation for the latissimus dorsi.

Answer 5

O: T7-L5 spinous processes, ribs 3-4, thoracolumbar fascia, inferior angle of scapula, posterior iliac crest

I: medial lip of groove of humerus

N: thoracodorsal nerve, off brachial plexus of C6-C8 nerve roots

A: humerus IR, extension, adduction; trunk rotation

Question 6

Describe the origin, insertion, action, and innervation for the levator scapulae.

Answer 6

O: transverse processes of C1-C4

I: superior medial border of scapula

N: dorsal scapular nerve, C5

A: scapular elevation and downward rotation

Question 7

Describe the origin, insertion, action, and innervation for the rhomboid major

Answer 7

O: T2-T5 spinous processes

I: medial border of scapula, inferior to insertion of rhomboid minor

N: dorsal scapular nerve, C5

A: scapular retraction, downward rotation, assists with elevation

Question 8

Describe the origin, insertion, action, and innervation for the rhomboid minor.

Answer 8

O: nuchal ligament, ligamentum nuchae, C7-T1 spinous processes

I: medial border of scapula, superior to insertion of rhomboid major

N: dorsal scapular nerve, C5

A: scapular retraction and downward rotation

Question 9

Describe the origin, insertion, action, and innervation for the Serratus posterior superior.

Answer 9

O: nuchal ligament, ligamentum nuchae, C7-T3 spinous processes

I: upper border of 2-5

N: T2-T5 ventral primary rami, 2nd-5th intercostal nerve

A: elevation of ribs 2-5, compression of deep muscles

Question 10

Describe the origin, insertion, action, and innervation for the Serratus posterior inferior.

Answer 10

O: T11-T12 spinous processes

I: inferior border of ribs 9-12

N: T9-T12 primary ventral rami, 9th-12th intercostal nerves

A: depression of lower ribs 9-12, aids in expiration, compression of deep muscles

Question 11

Describe the origin, insertion, action, and innervation for the erector spinae group.

Answer 11

Consists of iliocostalis (most lateral), longissimus (middle), and spinalis (most medial)
ILS - I Love Standing

O: spinous processes of T9-T12, medial slope of dorsal segment of iliac crest (common erector tendon - just deep to the thoracolumbar fascia)

I: spinous processes of T1, T2 and cervical vertebrae

N: posterior (dorsal) primary rami of spinal nerves, segmentally innervated depending on where in the spine you are.

A: extension of vertebral column

Iliocostalis group has cervicis, thoracis, lumborum segments

Longissimus group has capitus, cervicis, thoracis

Spinalis is thoracis

Question 12

What is included in the transverospinalis group?

Answer 12

Multifidus, rotatores, levatores costorum, semispinalis

Short muscles in the grooves between transverse and spinous processes of the vertebrae

Splenius capitis runs superficial to this group

Question 13

Describe the components of the rotatores.

Answer 13

Rotatores runs the entire length of the vertebral column, but is easiest to observe in the thoracic region.

Rotatores brevis - runs from lamina of one vertebra to transverse process of the next

Rotatores longus: runs from lamina of one vertebra to transverse process of the vertebra two levels below

Question 14

Name the muscles of the spine from superficial to deep.

Answer 14

Trapezius 
Latissimus dorsi
Serratus posterior
Erector spinae group (iliocostalis, longissimus, spinalis)
Semispinalis
Multifidus
Rotatores

Question 15

What is the lateral raphe? What muscles attach to it?

Answer 15

The junction of the anterior deep layer of the thoracolumbar fascia and the posterior superficial layer of the thoracolumabr fascia

Muscles that attach: transverse abdominis (most direct attachment), internal oblique, external oblique

Question 16

What muscles are enclosed by the thoracolumbar fascia?

Answer 16

Erector spinae group, multifidus

Question 17

Describe the blood supply of the vertebrae.

Answer 17

Each vertebra is supplied by periosteal and equatorial branches of the major cervical and segmental arteries and their spinal branches.

Segmental arteries and equatorial branches supply the vertebral body, and periosteal and nutrient arteries supply the bone posteriorly

Example of blood flow: aorta —> lumbar artery —> equatorial branch —> periosteal and nutrient branches

Blood drains via spinal venous plexuses

- anterior external venous plexus
- anterior internal plexus
- posterior internal plexus
- posterior external plexus

Basivertebral vains drain blood from within the vertebral bodies

Intervertebral veins drain bloood from plexuses

Question 18

Describe the origin, insertion, action, and innervation of the splenius capitis.

Answer 18

O: ligamentum nuchae, spinous processes of C7-T3

I: mastoid process, occipital bone

N: dorsal primary rami

A: head and neck rotation to same side, head/neck extension

Question 19

Describe the origin, insertion, action, and innervation of the splenius cervicis.

Answer 19

O: spinous processes of T3-T6

I: transverse processes of C1-C4

N: dorsal primary rami

A: head/neck same side rotation and extension

Question 20

Describe the origin, insertion, action, and innervation of the semispinalis.

Answer 20

3 parts - thoracis, cervicis, capitis, best developed in the cervical region.

Semispinalis capitis:

O: transverse processes of T1-T6

I: occipital bone

N: dorsal rami of the cervical spinal nerves

A: bilateral head extension, unilateral same side head rotation

Question 21

Describe the origin, insertion, action, and innervation of the multifidus.

Answer 21

Found from C2-S4 vertebrae, most prominent in lumbar region

O: vertebral arches

I: spinous processes, spanning 1-3 vertebrae

N: dorsal rami of the spinal nerves

A: unilateral - lateral trunk flexion and rotation to opposite side
bilateral - trunk extension

Question 22

Describe the origin, insertion, action, and innervation of the rotatores.

Answer 22

Found the entire length of the vertebral column, easiest to observe in thoracic region

O: transverse processes

I: spinous processes of superior vertebrae

N: dorsal rami of spinal nerves

A: rotation of superior vertebrae to opposite side (more proprioceptive role than biomechanical)