Oina, Muscles Of The Back - Intermediate And Deep Layers

Front 1

Serratus Posterior Superior

Back 1

O: ligamentum nuchae and spinous processes of C7 and T1-3 vertebrae
I: upper border of ribs 2-5
N: thoracic nerves
A: raises ribs 2-5, increasing thoracic cage. muscle of Inspiration

Front 2

Serratus Posterior Inferior

Back 2

O: spinous processes of T11-L3
I: inferior border of last 4 ribs (ribs 9-12) near their angles
N: thoracic nerves
A: draws ribs 9-12 outward and downward, counteracting inward pull of diaphragm. muscle of Exhalation

Front 3

Iliocostalis Lumborum

Back 3

O: iliac crest
I: angle of ribs
N: branches of the dorsal primary divisions of the spinal nerves
A: bilateral: extend the vertebral column (draw the ribs caudally)
Unilateral: lateral flexion same side, rotation opposite side

Front 4

Iliocostalis Thoracis

Back 4

O: angle of ribs
I: angle of ribs
N: branches of the dorsal primary divisions of the spinal nerves
A: bilateral: extend the vertebral column (draw the ribs caudally)
Unilateral: lateral flexion same side, rotation opposite side

Front 5

Iliocostalis Cervicis

Back 5

O: angle of ribs
I: transverse processes of cervical vertebrae
N: branches of the dorsal primary divisions of the spinal nerves
A: bilateral: extend the neck
Unilateral: lateral flexion same side, rotation same side

Front 6

Longissimus Thoracis

Back 6

O: sacrum
I: transverse processes
N: branches of the dorsal primary divisions of the spinal nerves
A: bilateral: extend the vertebral column (draw the ribs caudally)
Unilateral: lateral flexion same side, rotation opposite side

Front 7

Longissimus Cervicis

Back 7

O: transverse processes
I: transverse processes
N: branches of the dorsal primary divisions of the spinal nerves
A: bilateral: extend the neck
Unilateral: lateral flexion same side, rotation same side

Front 8

Longissimus Capitis

Back 8

O: transverse processes
I: mastoid process
N: branches of the dorsal primary divisions of the spinal nerves
A: bilateral: extend the head
Unilateral: lateral flexion of head same side, rotate face same side

Front 9

Spinalis Thoracis

Back 9

O: spinous processes
I: spinous processes
N: branches of the dorsal primary divisions of the spinal nerves
A: bilateral: extend the vertebral column

Front 10

Spinalis Cervicis
(blends with semispinalis)

Back 10

O: spinous processes
I: spinous processes
N: branches of the dorsal primary divisions of the spinal nerves
A: bilateral: extend the vertebral column

Front 11

Spinalis Capitis
(blends with semispinalis)

Back 11

O: blends in with semispinalis muscles
I: blends in with semispinalis muscles
N: branches of the dorsal primary divisions of the spinal nerves
A: bilateral: extend the vertebral column

Front 12

Splenius Capitis
Splenius Cervicis

Back 12

O: ligamentum nuchae and spinous processes of C7-T6
I: capitis portion – occipital bone and mastoid process
Cervicis portion – transverse processes of upper 2 or 3 cervical vertebrae
N: middle and lower cervical spinal nerves
A: bilateral: extend head and neck, unilateral: lateral flexion neck, rotate face same side

Front 13

Semispinalis Thoracis

Back 13

O: transverse processes of thoracic vertebrae
I: spinous processes of lower cervical and upper thoracic vertebrae
N: dorsal primary rami of spinal nerves
A: bilateral: extends vertebral column
Unil: rotates opposite side

Front 14

Semnispinalis Cervicis

Back 14

O: transverse processes of cervical vertebrae
I: spinous process of C2-5
N: dorsal primary rami of spinal nerves
A: bil: extends vertebral column
Unil: rotates opposite side

Front 15

Semispinalis Capitis

Back 15

O: transverse processes of cervical vertebrae
I: occipital bone
N: dorsal primary rami of spinal nerves
A: bil: extends the head
Unil: rotates head opposite side

Front 16

Multifidus
(easily seen in lumbar, but blends with semispinales and spinales in upper thoracic and cervical)

Back 16

O: groove on each side of spinous processes of vertebrae, accessory/mammary processes.
Covers lamina from sacrum to axis
I: spinous process of vertebra above. Each bundle ascends obliquely and inserts 2-5 vertebrae above
N: dorsal primary rami of spinal nerves
A: bil: extends vertebral column
Unil: rotates opposite side, lateral flexion same side

Front 17

Rotatores
(deepest group, length of vertebral column, best seen in thoracic)

Back 17

O: transverse processes of one vertebra
I: base of spinous process of the vertebra above
N: dorsal primary rami of spinal nerves
A: bil: extend the vertebral column
Unil: rotate opposite side

Front 18

Interspinales
(blend with
ligamentum nuchae in cervical)

Back 18

O: spinous processes
I: spinous processes
N: dorsal primary rami of spinal nerves
A: extends the vertebral column

Front 19

Intertransversarii
(easily seen in thoracic)

Back 19

O: transverse processes
I: transverse processes
N: dorsal primary rami of spinal nerves
A: bil: extend the vertebral column
Unil: lateral flexion same side

Front 20

Levator Costorum

Back 20

O: transverse processes of C7-T11
I: the rib below, close to the tubercle
N: dorsal primary rami of spinal nerves
A: raises ribs, increasing thoracic cavity in inspiration

Front 21

Transversospinal muscles

Back 21

1. semispinalis
2. multifidus
3. rotatores

Front 22

Erector spinae (sacrospinalis)

Back 22

1. iliocostalis
2. longissimus
3. spinalis

Front 23

What do semispinales and rotatores do?

Back 23

extend and rotate to the opposite side.


they DO NOT laterally flex.

Front 24

Erector spinae (sacrospinalis)

spinalis

Back 24

thoracis

cervicis - cant be seen, blends w/ semispinalis

capitis - cant be seen, blends w/ semispinalis

Front 25

Erector spinae (sacrospinalis)

longissimus

Back 25

thoracis

cervicis

capitis

Front 26

Erector spinae (sacrospinalis)

iliocostalis

Back 26

lumborum

thoracis

cervicis

Front 27

semispinalis

Back 27

thoracis

cervicis

capitis