Intrinsic Back Muscles - Dorsal Rami Spinal Nerves

Question 1

Superficial Layer: Splenius mm. (2)

1. Splenius Capitis

Answer 1

Origin: Cerevical spinous processes and nuchal ligament

Insertion: Mastoid process of temporal bone, superior nuchal line

Innervation: Dorsal rami spinal nerves

Function:
1. Capital extension
2. Rotation of head to same side
3. Lateral bending of head to same side

Question 2

2. Splenius Cervicis

Answer 2

Origin: Spinous processes

Insertion: Transverse processes, posterior tubercles

Innervation: Dorsal rami spinal nerves

Function:
1. Extension and Rotation of cervical spine to same side
2. Lateral bending to same side

Question 3

Intermediate layer: Erector spinae mm. - Iliocostalis (3)

1. Iliocostalis Lumborum

Answer 3

Origin: Common tendon of erector spinae, thoracolumbar fascia, Iliac crest, sacrum

Insertion: Transverse process, Ribs 5/6-12

Innervation: Dorsal rami spinal nerves

Function:
1. Extension of spine
2. Lateral bending of spine on the same side
3. Depression of ribs
4. Elevation of pelvis

Question 4

2. Iliocostalis Thoracis

Answer 4

Origin: Ribs 12-7

Insertion: Ribs 1-6, C7 transverse process

Innervation: Dorsal rami spinal nerves

Function:
1. Extension and Lateral bending of spine on the same side
2. Elevation of pelvis

Question 5

3. Iliocostalis Cervicis

Answer 5

Origin: Ribs 3-6

Insertion: Transverse processes, posterior tubercles

Innervation: Dorsal rami spinal nerves

Function:
1. Extension of cervical spine
2. Lateral bending to same side
3. Depression of ribs

Question 6

Erector spinae mm. - Longissimus (3)

1. Longissimus Thoracis

Answer 6

Origin: Common origin

Insertion: Transverse processes, Ribs 2-12

Innervation: Dorsal rami spinal nerves

Function:
1. Extension of spine
2. Lateral bending to same side (unilateral muscle)
3. Depression of ribs

Question 7

2. Longissimus Cervicis

Answer 7

Origin: Transverse processes

Insertion: Posterior tubercles of transverse processes

Innervation: Dorsal rami spinal nerves

Function:
1. Extension of cervical spine
2. Lateral bending of cervical spine to same side

Question 7

Longissimus Capitis
3. (below Splenius Cervicis)

Answer 7

Origin: transverse processes T1-T4, C4-C7

Insertion: Mastoid process of temporal bone

Innervation: Dorsal rami spinal nerves

Function:
1. Capital extension
2. Lateral bending and rotation of head to same side

Question 7

Erector spinae mm. - Spinalis (3)
1. Spinalis Thoracis

Answer 7

Origin: T11-L2 Spinous processes

Insertion: T1-L4 spinous processes

Innervation: Dorsal rami spinal nerves

Function: Extension of spine

Question 8

2. Spinal Cervicis
   (below splenius capitis)

Answer 8

Origin: Spinous processes, nuchal ligament

Insertion: Axis, spinous processes

Innervation: Dorsal rami spinal nerves

Function: Extension of cervical spine

Question 9

3. Spinal Capitis

Answer 9

Origin: Spinous processes

Insertion: Occiput

Function: Capital extension

Innervation: Dorsal rami spinal nerves

Question 10

Deep layer: Transversospinalis mm. - Semispinalis (3)

1. Semispinalis Thoracis

Answer 10

Origin: (from) Thoracic transverse processes

Insertion: (to) Cervical spinous processes

Innervation: Dorsal rami spinal nerves

Function: Extension of thoracic spine

Question 11

2. Semispinalis Cervicis

Answer 11

Origin: Thoracic transverse processes

Insertion: Cervical spinous processes

Innervation: Dorsal rami spinal nerves

Function:
1. Extension of cervical spine
2. Rotation of c-spine to opposite side
3. Lateral bending to same side

Question 12

3. Semispinalis Capitis

Answer 12

Origin: Transverse processes, cervical articular processes

Insertion: Occiput

Innervation: Dorsal rami spinal nerves

Function:
1. Capital extension
2. 
Rotation of head to opposite side
3. Lateral bending of head to same side

Question 13

Multifidus (1)

Answer 13

Origin:
1. Sacrum
2. Aponeurosis of Erector spinae
3. Posterior superior iliac spine
4. Sacroiliac ligaments
5. Lumbar mamillary processes
5. Thoracic transverse processes
5. Cervical articular processes

Insertion: Higher spinous processes

Innervation: Dorsal rami spinal nerves

Function:
1. Extension of spine
2. Lateral bending of spine (unilateral muscle)
3. Rotation to opposite side

Question 14

Rotatores (2)
Rotatores brevis and longus

Answer 14

Origin: Transverse processes

Insertion: Superior (higher level) spinous process
Brevis (short): SP of next vertebrae above
Longus: SP of 2nd vertebrae above

Innervation: Dorsal rami spinal nerves

Function:
1. Extension of spine
2. Rotation of spine to opposite side

Question 15

Small muscles of deep back:
1. Interspinalis (3)

Answer 15

Innervation: Dorsal rami spinal nerves

Function:
Connect spinous processes
Extension and rotation of vertebral column

Question 16

2. Intertransversarii

Answer 16

Innervation: Dorsal rami spinal nerves

Function:
Connect transverse processes
Lateral flexion of vertebral column
Stabilize vertebral column

Question 17

Levatores Costarum (2)
Breves and Longus

Answer 17

Insertion: transverse processes to rib tubercles

Innervation: Dorsal rami spinal nerves

Function:
1. Elevates ribs (costa ribs)
2. Assist with lateral flexion and respiration