Back Myology

Question 1

Layer 1

Answer 1

Extrinsic

Trapezius Muscle
Latissimus Dorsi Muscle

Question 2

Trapezius Muscle

Answer 2

Actions
Whole- Sup rotate glenoid cavity, retract scapula
Upper- Elevate scapula, extend neck, rotate face away
Lower- Depress scapula

Innervation: Accessory Cranial Nerve XI

Transverse cervical artery

Question 3

Latissimus Dorsi Muscle

Answer 3

Actions: Extend, Adduct, and medially rotate humerus
Inferior rotate glenoid cavity

Innervation: Thoracodorsal Nerve

Thoracodorsal Artery

Question 4

Layer 2

Answer 4

Extrinsic

Rhomboid Major
Rhomboid Minor
Levator Scapulae

Question 5

Rhomboid Major

Answer 5

Action: Retract and Elevate Scapula, Inferior rotate glenoid cavity

Innervation: Dorsal Scapular Nerve

Dorsal Scapular Artery

Question 6

Rhomboid Minor

Answer 6

Action: Retract and Elevate Scapula, Inferior rotate glenoid cavity

Innervation: Dorsal Scapular Nerve

Dorsal Scapular Artery

Question 7

Levator Scapulae

Answer 7

Action: Elevate scapula, Inferior rotate glenoid cavity, Extend and Laterally flex neck

Innervation: Dorsal Scapular Nerve

Dorsal Scapular Artery

Question 8

Layer 3

Answer 8

Extrinsic

Serratus Posterior Superior Muscle
Serratus Posterior Inferior Muscle

Question 9

Serratus Posterior Superior Muscle

Answer 9

Action: Elevate Ribs, Mostly Proprioception

Innervation: Intercostal Nerve

Intercostal Artery

Question 10

Serratus Posterior Inferior Muscle

Answer 10

Action: Depress Ribs, Mostly Porprioception

Innervation: Anterior Rami

Intercostal Artery

Question 11

Layer 4

Answer 11

Intrinsic… all innervated by posterior rami

Splenius Capitus Muscle
Splenius Cervicus Muscle

Question 12

Splenius Capitus Muscle

Answer 12

Action: Extend neck, Rotate face towards and laterally flex neck

Occipital Artery

Question 13

Splenius Cervicis Muscle

Answer 13

Action: Extend neck, rotate face towards and laterally flex neck

Occipital Artery

Question 14

Layer 5

Answer 14

Intrinsic… all innervation by posterior rami

Erector Spinae Group:
Iliocostalis Muscle (lateral)
Longissimus Muscle (intermediate)
Spinalis Muscle (medial)

Question 15

Iliocostalis Muscle

Answer 15

Action: Erect posture, Extend vertebral column and head, Laterally flex vertebral column

3 Parts: Lumborum, Thoracis and Cervicis
Posterior intercostal and lumbar arteries

Question 16

Longissimus Muscle

Answer 16

Action: Erect posture, Extend spine and head, laterally flex spine

3 parts: Thoracis, Cervicis and Capitis (rotates face towards)
Posterior intercostal arteries and occipital artery (capitis)

Question 17

Spinalis Muscle

Answer 17

Actions: Erect posture, Extend spine and head, Laterally flex spine

3 parts but hard to distinguish
Posterior intercostal arteries

Question 18

Layer 6

Answer 18

Intrinsic…innervation by posterior rami

Transversospinalis Group:
Semispinalis Muscle
Multifidus Muscle
Rotatores Longus Muscle
Rotatores Brevis Muscle

Question 19

Semispinalis Muscle

Answer 19

Actions:
Thoracis/Cervicis- Extend spine and rotate spine away
Capitis- Extend head and rotate head away

Posterior intercostal arteries (thoracis) and deep cervical arteries

Question 20

Multifidus Muscle

Answer 20

Actions: Extend Spine and rotate spine away

Posterior lumbar arteries

Question 21

Rotatores Longus

Answer 21

Actions: Extend spine, rotate spine away, mostly proprioception

Posterior intercostal arteries

Question 22

Rotatores Brevis

Answer 22

Actions: Extend spine and rotate spine away, mostly proprioception

Posterior intercostal arteries

Question 23

Interspinalis Muscle

Answer 23

Action: Extend spine

Vertebral, occipital and posterior intercostal arteries

Question 24

Intertransversarii Muscle

Answer 24

Action: Laterally flex spine

Deep cervical, vertebral and posterior intercostal arteries

Question 25

Suboccipital Muscles

Answer 25

Rectus Capitis Posterior Major Muscle Rectus Capitis Posterior Minor Muscle Obliquus Capitis Inferior Muscle Obliquus Capitis Superior Muscle

Question 26

Rectus Capitis Posterior Major Muscle

Answer 26

Actions: Extend Head, rotate face toward Innervation: Suboccipital nerve Vertebral and occipital arteries

Question 27

Rectus Capitis Posterior Minor Muscle

Answer 27

Action: Extend Head Innervation: Suboccipital nerve Vertebral and occipital arteries

Question 28

Obliquus Capitis Inferior Muscle

Answer 28

Action: rotate face toward Innervation: Suboccipital nerve Vertebral and occipital arteries *not actually attached to Head ( C2 to C1)

Question 29

Obliquus Capitis Superior Muscle

Answer 29

Actions: Extend and Laterally flex head Innervation: Suboccipital nerve Vertebral and occipital arteries