Deep Back Muscles

Question 1

What are the muscles that make up the deep back?

Answer 1

Splenious capitus, splenious cervicis, erector spinae (3 muscles), transversospinalis (3 muscles), and suboccipital.

Question 2

What innervates the deep back muscles?

Answer 2

Dorsal rami of spinal nerves.

Question 3

What is the origin of the splenious capitis?

Answer 3

Lower half of the liamentum nuchae, spinous processes C7-T4.

Question 4

What is the insertion of the splenious capitis?

Answer 4

Mastoid process of the skull and below the lateral 1/3 of the superior nuchal line.

Question 5

What are the actions of the splenious capitis?

Answer 5

Bilateral contraction - extension of the neck

Unilateral contraction - Draw and rotate the head to one side

Question 6

What innervates the splenious capitis?

Answer 6

Segmentally by the dorsal rami of cervical nerves.

Question 7

What is the origin of the splenious cervicis?

Answer 7

Spinous processes T3-T6.

Question 8

What is the insertion of the splenious cervicis?

Answer 8

Transverse processes C1-C3.

Question 9

What are the actions of the splenious cervicis?

Answer 9

Bilateral contraction - extension of the neck.

Unilateral contraction - draw and rotate the head to one side.

Question 10

What innervates the splenious cervicis?

Answer 10

Segmentally by the dorsal rami of the cervical nerves.

Question 11

What 3 muscles make up the erector spinae?

Answer 11

Iliocostalis, Longissimus, and Spinalis.

Question 12

What is the origin of the iliocostalis?

Answer 12

Ilium and ribs.

Question 13

What is the origin of the longissimus?

Answer 13

Transverse processes.

Question 14

What is the origin of the spinalis?

Answer 14

Spinous processes.

Question 15

What is the insertion of the iliocostalis?

Answer 15

Ribs and Transverse processes.

Question 16

What is the insertion of the longissimus?

Answer 16

Transverse processes.

Question 17

What is the insertion of the spinalis?

Answer 17

Spinous processes.

Question 18

What are the actions of the erector spinae?

Answer 18

Bilateral contraction - extension of the vertebral column and controls posture.
Unilateral contraction - Lateral flexion of vertebral column.

Question 19

What innervates the erector spinae muscles?

Answer 19

Segmentally by the dorsal rami of the spinal nerves.

Question 20

What 3 muscles make up the transversospinalis?

Answer 20

Semispinalis, Multifidus, and Rotatores.

Question 21

What is the origin of the transversospinalis muscles?

Answer 21

All originate from transverse processes of vertebrae.

Question 22

What is the insertion of the transversospinalis muscles?

Answer 22

All insert upon the spines of vertebrae, superior to origin. Each muscle spans a different length of vertebrae.

Question 23

What are the actions of the transversospinalis muscles?

Answer 23

Bilateral contraction - extension of the vertebral column
Unilateral contraction - Rotation of the vertebral column to contralateral side of the contracting muscle or muscle group.

Question 24

What innervates the transversospinalis muscles?

Answer 24

Segmentally by dorsal rami of the thoracolumbar spinal nerve.

Question 25

What 4 muscles make up the suboccipital?

Answer 25

Rectus Capitis Posterior Major and Minor, and Obliquus Capitis Superior and Inferior.

Question 26

What is the origin of the Rectus Capitis Posterior Major?

Answer 26

Spinous process of the axis vertebrae (C2).

Question 27

What is the origin of the Rectus Capitis Posterior Minor?

Answer 27

Posterior tubercle of the atlas vertebrae (C1).

Question 28

What is the origin of the Obliquus Capitis Superior?

Answer 28

Transverse process of axis vertebrae (C2).

Question 29

What is the origin of the Obliquus Capitis Inferior?

Answer 29

Spinous process of axis vertebrae (C2).

Question 30

What is the insertion of the Rectus Capitis Posterior Major?

Answer 30

Lateral part of the inferior nuchal line of the occipital bone.

Question 31

What is the insertion of the Rectus Capitis Posterior Minor?

Answer 31

Medial part of the inferior nuchal line of the occipital bone.

Question 32

What is the insertion of the Obliquus Capitis Superior?

Answer 32

Occipital bone. (Lateral half inferior nuchal line)

Question 33

What is the insertion of the Obliquus Capitis Inferior?

Answer 33

Transverse process atlas vertebrae (C1).

Question 34

What are the actions of the Rectus Capitis Posterior Major?

Answer 34

Extension of the head, and ipsilateral rotation of the head.

Question 35

What are the actions of the Rectus Capitis Posterior Minor?

Answer 35

Extension of the head.

Question 36

What are the actions of the Obliquus Capitis Superior?

Answer 36

Extension of the head, and bends ipsilaterally.

Question 37

What are the actions of the Obliquus Capitis Inferior?

Answer 37

Ipsilateral rotation of the face.

Question 38

What innervates the suboccipital muscles?

Answer 38

Suboccipital nerve (posterior rami of C1).

Question 39

What muscles make up the suboccipital triangle?

Answer 39

Medial - Rectus Capitis Posterior Major Lateral - Obliquus Capitis Superior Inferior - Obliquus Capitis Inferior.

Question 40

What are some of the contents of the suboccipital triangle?

Answer 40

Vertebral artery, suboccipital nerve, suboccipital venous plexus.