Extrinsic Back Muscles Flashcards Preview

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Flashcards in Extrinsic Back Muscles Deck (29):
1

What are the extrinsic back muscles

Trapezius, latissumus dorsi, levator scapulae, rhomboids

2

Trapezius origin

medial third of superior nuchal line
external occipital protuberance
nuchal ligament
spinous process of C7-T12 vertebrae

3

Trapezius insertion

lateral third of clavicle; acromion and spine of scapula

4

trapezius innervation

spinal accessory nerve (CNXI)
C3 and C4

5

Latissimus Dorsi origin

spinous processes of inferior six thoracic vertebrae
thoracolumbar fascia
iliac crest
inferior three or four ribs

6

latissimus dorsi insertion

floor of intertubercular sulcus of humerus

7

latissimus dorsi innervation

thoracodorsal nerve
C6, C7, C8

8

Levator scapulae origin

posterior tubercles of transverse processes of C1-C4 vertebrae

9

Levator Scapulae insertion

medial border of scapula superior to root of spine

10

levator scapilae innervation

dorsal scapular (C5) and cervical spinal nerves (C3, C4)

11

rhomboid minor originate

nuchal ligament
spinous processes of C7 and T1 vertebrae

12

rhomboid minor insertion

triangular area at medial end of scapular spine

13

rhomboid minor innervation

dorsal scapular nerve
C4, C5

14

rhomboid major origin

spinous processes of T2- T5 vertebrae

15

rhomboid major insertion

medial border of scapula from level of spine to inferior angle

16

rhomboid major innervation

dorsal scapular nerve
C4, C5

17

trapezius main actions

descending (superior): elevation
ascending (inferior): depresses
middle part or all together: retracts scapula
descending and ascending act together to rotate glenoid cavity superiorly

18

latissimus dorsi main actions

extends, adducts and medially rotates shoulder joint
raises body towards arms during climbing

19

levator scapulae main actions

elevates scapula and tilts the glenoid cavity inferiorly by rotating scapula

20

rhomboids main actions

retract scapula and rotate it to depress glenoid cavity
fix scapula to thoracic wall

21

intermediate extrinsic back muscles

serratus posterior superior and inferior

22

posterior serratus superior origin

nuchal ligament
spinous processes C7-T3

23

posterior serratus superior insertion

superior border of ribs 2 to 4

24

posterior serratus superior innervation

2nd to 5th intercostal nerves

25

posterior serratus superior action

elevates ribs

26

posterior serratus inferior origin

spinous processes of T11 to L2

27

posterior serratus inferior insertion

inferior borders ribs 8 to 12

28

posterior serratus inferior innervation

spinal nerves T9 to T12 (anterior rami)

29

posterior serratus inferior action

depression of ribs