Lecture 10- Extrinsic Back Muscles Flashcards Preview

CHI282 - Human Anatomy 2 > Lecture 10- Extrinsic Back Muscles > Flashcards

Flashcards in Lecture 10- Extrinsic Back Muscles Deck (39):
0

Superficial extrinsic
•Posterior axio-appendicular muscles => connect ...... skeleton with ....... ........ skeleton (pectoral girdle and humerus).

axial
superior appendicular

1

Superficial extrinsic
•Produce & control ........ ...... .......

upper limb movements

2

Superficial extrinsic
•Mostly innervated by ....... ........ of cervical spinal nerves (despite being dorsal muscles!).

anterior rami

3

Superficial extrinsic muscles
•Include:


•Trapezius
•Latissimus dorsi
•Levator scapulae
•Rhomboid major
•Rhomboid minor

4

Trapezius
Proximal attachment

Meidal third of superior nuchal line; external occiptal protuberance; nuchal ligament; spinous processes of C7-T12 vertebrae

5

Trapezius
Distal attachment

Lateral third of clavicle; acromion and spine of scapula

6

Trapezius
Innervation

Motor: Spinal accessory nerve (CN XI)
Sensory: C3 & C4 spinal nerves

7

Trapezius
Main actions


Descending part elevates; ascending part depresses; middle part (or all parts together) retracts scapula;
Descending and ascending parts together rotate glenoid cavity superiorly.

8

Latissimus dorsi
Proximal attachment

Spinous processes of T7 to T12, thoracolumbar fascia, iliac crest, ribs 10-12

9

Latissimus dorsi
Distal attachment

Floor of intertubular sulcus of humerus

10

Latissimus Dorsi
Innervation

Thoracodorsal nerve
(C6, C7, C8)

11

Latissimus Dorsi
Main Action

Extends, adducts and medially rotates humerus
Raises body toward arms during climbing

12

Levator scapulae
Proximal attachment

Posterior tubercles of transverse processes of C1-C4 vertebrae

13

Levator scapulae
Distal attachment

Medial border of scapula superior to root of scapular spine

14

Levator Scapula
Innervation

Dorsal scapular (C5) and cervical (C3, C4) nerves

15

Levator scapulae
Main actions

Elevates scapula
Tilts glenoid cavity inferiorly (by rotating scapula)

16

Rhomboid major
Proximal attachment

Spinous processes
of T2-T5 vertebrae

17

Rhomboid Major
Distal attachment

Medial border of scapula from level of spine to inferior angle

18

Rhomboid Major
Innervation

Dorsal scapular nerve
(C4, C5)

19

Rhomboid Major
Main actions

Retracts scapula and rotate it to depress glenoid cavity
Fix scapula to thoracic wall

20

Rhomboids minor
Proximal attachment

Nuchal ligament
Spinous processes of C7 & T1 vertebrae

21

Rhomboid Major
Distal attachment

Smooth triangular area at medial end of scapular spine

22

Rhomboid Minor
Innervation


Dorsal scapular nerve
(C4, C5)

23

Rhomboid Minor
Main actions

Retracts scapula and rotate it to depress glenoid cavity
Fix scapula to thoracic wall

24

Rhomboid Minor
Intermediate extrinsic

•Serratus posterior superior
•Serratus posterior inferior

25

Intermediate extrinsic
No what?
Innervation?

No respiratory function
Innervated by intercostal nerves.

26

Serratus posterior superior
Superior attachment

Nuchal ligament, spinous processes of C7 to T3

27

Serratus posterior superior
Inferior attachment

Superior borders of 2nd to 4th ribs

28

Serratus posterior superior
Innervation

2nd to 5th intercostal nerves

29

Serratus posterior superior
Main action

Proprioception
(Elevates ribs)

30

Serratus posterior inferior
Superior attachment

Spinous processes
of T11 to L2

31

Serratus posterior inferior
Inferior attachment

Inferior borders of 8th to 12th ribs near their angles

32

Serratus posterior inferior
Innervation

Anterior rami to T9 to T12 thoracic spinal nerves

33

Serratus posterior inferior
Main Action

Proprioception
(Depress ribs)

34

The thoracodorsal nerve innervates which extrinsic back muscle?

Latissimus Dorsi

35

Which nerve provides motor innervation to trapezius?

Motor: Spinal accessory nerve (CN XI)

36

What is the main action of levator scapulae?

Elevates the scapula

37

Which nerve spinal cord segments contribute to the dorsal scapular nerve?

C4, C5

38

What is the main action of the serratus posterior muscles?

Proprioception