Intrinsic Muscles of the Back

Question 1

How many Muscles make up the Superficial (Spinotransversales) Layer?

Answer 1

2 - Splenius Captius

Splenius Cervicis

Question 2

What is the Origin of Splenius Capitus?

Answer 2

Lower Aspect of Ligamentum Nuchae and the Spinous Processes of C7-T3/4 Vertebrae

Question 3

What is the Attachment of Splenius Capitus?

Answer 3

Mastoid Process and the Occipital Bone of the Skull

Question 4

What is the Action of Splenius Capitus?

Answer 4

Rotate head to Same Side.

Question 5

What is the Innveration of Splenius Capitus?

Answer 5

Posterior Rami of Spinal Nerves C3 and C4

Question 6

What is the Origin of Splenius Cervicis?

Answer 6

Spinous Processes of T3-T6 Vertebrae

Question 7

What is the Attachment of Splenius Cervicis?

Answer 7

Transverse Processes of C1-C3/4

Question 8

What is the Action of Splenius Cervicis?

Answer 8

Rotate Head to the Same Side.

Question 9

What is the Innervation of Splenius Cervicis?

Answer 9

Posterior Rami of the Lower Cervical Spinal Nerves

Question 10

What is the Joint Action of Splenius Capitus and Splenius Cervicis?

Answer 10

Extend the Head and Neck

Question 11

How many Muscles make up the Intermediate Layer?

Answer 11

3 - Iliocostalis (Most Lateral)
Longissimus
Spinalis (Most Medial)

Question 12

What do the Intermediate Muscles Collectively Form?

Answer 12

Erector Spinae

Question 13

Where is the Erector Spinae Located in Relation to the Spinal Column

Answer 13

Posteriolaterally, between the Vertebral Spinous Processes and the Costal Angle of the Ribs

Question 14

What do the Intermediate Muscles have in Common?

Answer 14

Common Tedinous Origin Arising from:
•	Lumbar and Thoracic Vertebrae
•	Sacrum
•	Posterior aspect of the Iliac Crest
•	Sacroiliac and Supraspinous Ligaments

Question 15

What is the Origin of Iliocostalis?

Answer 15

Common Tendinous Origin

Question 16

What is the Attachment of Iliocostalis?

Answer 16

Costal Angle of the Ribs and the Cervical Spinous Processes

Question 17

What is the Action of Iliocostalis?

Answer 17

Acts Unilaterally to Laterally Flex the Vertebral Column. Acts Bilaterally to Extend the Vertebral Column and the Head.

Question 18

What is the Innervation of Iliocostalis?

Answer 18

Posterior Rami of the Spinal Nerves

Question 19

What is the Origin of Longissimus?

Answer 19

Common Tendinous Origin

Largest of the 3. Can be Divided into 3 Parts – Thoracic, Cervicis and Capitis.

Question 20

What is the Attachment of Longissimus?

Answer 20

Lower Ribs, the Transverse Processes of C2-T12 and the Mastoid Process of the Skull.

Question 21

What is the Action of Longissimus?

Answer 21

Acts Unilaterally to Laterally Flex the Vertebral Column. Acts Bilaterally to Extend the Vertebral Column and the Head.

Question 22

What is the Innervation of Longissimus?

Answer 22

Posterior Rami of the Spinal Nerves

Question 23

What is the Origin of Spinalis?

Answer 23

Common Tendinous Origin

Question 24

What is the Attachment of Spinalis?

Answer 24

Spinous Processes of C2, T1-T8 and the Occipital Bone of the Skull.

Question 25

What is the Action of Spinalis?

Answer 25

Acts Unilaterally to Laterally Flex the Vertebral Column. Acts Bilaterally to Extend the Vertebral Column and the Head.

Question 26

What is the Innervation of Spinalis?

Answer 26

Posterior Rami of the Spinal Nerves

Question 27

What are the Main Deep Muscles of the Back?

Answer 27

Semispinalis (Most Superficial) Multifidus (Deep to Semispinalis) Rotatores (Most Common in Thoracic Region)

Question 28

What is the Origin of Semispinalis?

Answer 28

Transverse Processes of C4-T10. The Fibres Ascend 4-6 Vertebral Segments.

Question 29

What is the Attachment of Semispinalis?

Answer 29

Spinous Processes of C2-T4 and the Occipital Bone of the Skull

Question 30

What is the Action of Semispinalis?

Answer 30

Extends and Contralaterally Rotates the Head and Vertebral Column

Question 31

What is the Innervation of Semispinalis?

Answer 31

Posterior Rami of the Spinal Nerves

Question 32

What is the Origin of Multifidus?

Answer 32

Sacrum, Posterior Iliac Spine, Common Tendinous Origin of the Erector Spinae, Mammillary Processes of the Lumbar Vertebrae, Transverse Processes of T1-T3 and Articular Processes of C4-C7.

Question 33

What is the Attachment of Multifidus?

Answer 33

The Fibres Ascend 2 Vertebral Levels then Attach to the Spinous Processes of the Vertebrae.

Question 34

What is the Action of Multifidus?

Answer 34

Stabilises the Vertebral Column

Question 35

What is the Innervation of Multifidus?

Answer 35

Posterior Rami of the Spinal Nerves

Question 36

What is the Origin of Rotatores?

Answer 36

Vertebral Transverse Processes

Question 37

What is the Attachment of Rotatores?

Answer 37

Lamina and Spinous Processes of the Immediately Superior Vertebrae

Question 38

What is the Action of Rotatores?

Answer 38

Stabilises the Vertebral Column, and Has a Proprioception Function.

Question 39

What is the Innervation of Rotatores?

Answer 39

Posterior Rami of the Spinal Nerves

Question 40

What are the Minor Deep Muscles of the Back?

Answer 40

Interspinales Intertranversari Levatores Costarum

Question 41

Attachments of Interspinales

Answer 41

Span between Adjacent Spinous Processes

Question 42

Action of Interspinales

Answer 42

Acts to Stabilise the Vertebral Column

Question 43

Attachments of Intertranversari

Answer 43

Spans between Adjacent Transverse Processes

Question 44

Action of Intertranversari

Answer 44

Acts to Stabilise the Vertebral Column

Question 45

Attachments of Levatores Costarum

Answer 45

Originates form the Transverse Processes of C7-T11 and Attaches to the Rib Immediately Below.

Question 46

Action of Levatores Costarum

Answer 46

Acts to Elevate the Ribs.