Shoulder Muscles Flashcards Preview

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Flashcards in Shoulder Muscles Deck (59):
1

pec major
-origin

clavicular head
-anterior surface of sternal 1/2 of clavicle
sternocostal head
-anterior surface of sternum
-adjacent superior 6 costal cartilages
-aponeurosis of external oblique

2

pec major
-insertion

common tendon to lateral lip of intertubercular groove

3

pec major
-action

both heads
-adducts and internally rotates humerus
clavicular head
-flexes humerus
sternocostal head
-extends humerus

4

pec major
-innervation

clavicular head
-lateral pectoral nerve (C5, C6)
sternocostal head
-medial pectoral nerve (C7-T1)
-C7 comes from communicating branch off lateral pectoral nerve

5

pectoralis minor
-orign

ribs 3-5 near their costal cartilages

6

pectoralis minor
-insertion

medial border and superior surface of coracoid process or scapula

7

pectoralis minor
-actions

stabilized scapula by pulling it anteriorly and inferiorly against thoracic wall
protraction (minor) by moving scapula laterally and anteriorly around thoracic cage

8

pectoralis minor
-innervation

medial pectoral nerve (C8, T1)

9

subclavius
-origin

junction of rib 1 and its costal cartilage

10

subclavius
-insertion

inferior surface of middle 1/3 of clavicle

11

subclavius
-action

draws clavicle medially

12

subclavius
-innervation

nerve to subclavius (C5, C6)

13

serratus anterior
-origin

external surfaces of lateral parts of ribs 1-8
fascia overlying external intercostal muscles

14

serratus anterior
-insertion

anterior surface of medial border of scapula

15

serratus anterior
-action

protracts scapula and holds it against thoracic wall (along with subclavius)
rotates scapula (pulls on inferior angle of scapula; assists trapezius)

16

serratus anterior
-innervation

long thoracic nerve (C5-C7)

17

what are the pectoral muscles

pec major
pec minor
subclavius
serratus anterior

18

what are the extrinsic muscles of the back?

trapezius
latissimus dorsi
levator scapulae
rhomboid major/minor

19

trapezius
-origin

medial 1/3 of superior nuchal line
external occipital protuberance
ligamentum nuchae
spinous processes of C7-T12
lumbar and sacral spinous processes via pulling on thoracolumbar fascia

20

trapezius
-insertion

lateral 1/3 of clavicle
acromion and spine of scapula
superior fibers extend more laterally, while inferior fibers insert on the spine as an aponeurosis, withous extending out to the acromion

21

trapezius
-actions

superior fibers
-elevate
middle fibers
-retract
inferior fibers
-depress
superior and inferior fibers together
-superiorly rotate lateral angle (assisted by serratus anterior)

22

trapezius
-innervation

spinal accessory nerve (CN XI)
ventral rami of cervical nerves C3, C4 (primarily sensory for proprioceptive and pain sensation)

23

latissimus dorsi
-origin

spinous process of the inferior 6 thoracic vertebrae
thoracolumbar fascia
iliac crest
inferior 3-4 ribs (9-12)

24

latissimus dorsi
-insertion

floor of intertubercular groove of humerus

25

latissimus dorsi
-actions

humerus extension
humerus adduction
humerus internal rotation
raises body towards arms during climbing

26

latissimus dorsi
-innervation

thoracodorsal nerve (C6-C8)

27

levator scapulae
-origin

posterior tubercles of transverse process of C1-C4 vertebrae

28

levator scapulae
-insertion

superior part of medial border of scapula

29

levator scapulae
-action

elevates scapula
inferiorly rotates lateral angle of scapula

30

levator scapulae
-innervation

dorsal scapular nerve (C5)
cervical nerve (C3, C4)

31

rhomboid minor/major
-origin

minor
-ligamentum nuchae
-spinous process of C7, T1
major
-spinous processes of T2-T5

32

rhomboid minor/major
-insertion

medial border of scapula from level of spine of scapula to inferior angle

33

rhomboid minor/major
-actions

retracts scapula
inferiorly rotates lateral angle, depressing glenoid cavity
fixes scapula to thoracic wall

34

rhomboid minor/major
-innervation

dorsal scapular nerve (C4, C5)

35

what are the scapular muscles (scapulohumeral muscles)

deltoid
supraspinatus
infraspinatus
teres minor
teres major
subscapularis

36

deltoid
-origin

lateral 1/3 of clavicle
acromion
spine of scapula

37

deltoid
-insertion

deltoid tuberosity of humerus

38

deltoid
-actions

anterior part
-arm flexion
-arm medial rotation
middle part
-arm abduction
posterior part
-extends arm
-laterally rotates arm

39

deltoid
-innervation

axillary nerve (C5, C6)

40

supraspinatus
-origin

supraspinous fossa of scapula

41

supraspinatus
-insertion

superior facet of greater tubercle of humerus

42

supraspinatus
-action

abducts arm (assists deltoid)

43

supraspinatus
-innervation

suprascapular nerve (C4-C6)

44

infraspinatus
-origin

infraspinous fossa of scapula

45

infraspinatus
-insertion

middle facet on greater tubercle of humerus

46

infraspinatus
-action

arm external rotation
helps hold head of humerus in glenoid cavity (as rotator cuff muscle)

47

infraspinatus
-innervation

suprascapular nerve (C5, C6)

48

teres minor
-origin

superior part of lateral border of scapula

49

teres minor
-insertion

inferior facet on greater tubercle of humerus

50

teres minor
-action

arm external rotation
helps hold head of humerus in glenoid cavity

51

teres minor
-innervation

axillary nerve (C5, C6)

52

teres major
-origin

dorsal surface of inferior angle of scapula

53

teres major
-insertion

medial lip of intertubercular groove of humerus

54

teres major
-action

arm adduction
arm internal rotation

55

teres major
-innervation

lower subscapular nerve (C5, C6)

56

subscapularis
-origin

subscapular fossa

57

subscapularis
-insertion

lesser tubercle of humerus

58

subscapularis
-action

arm internal rotation
arm adduction
helps hold head of humerus in glenoid cavity

59

subscapularis
-innervation

upper and lower subscapular nerve (C5-C7)