Shoulder/scapula Flashcards Preview

Muscles of back/upper extremity > Shoulder/scapula > Flashcards

Flashcards in Shoulder/scapula Deck (33):
1

Scapulohumeral (intrinsic shoulder) muscles

deltoid, supraspinatus, infraspinatus, teres minor, teres major, subscapularis

2

Attachments of deltoid

Proximal: lateral third of clavicle, acromion and spine of scapula
Distal: deltoid tuberosity of humerus

3

Innervation of deltoid

axillary nerve (C5, C6)

4

Action of deltoid

anterior: flex and medially rotates arm
acromial (middle): abducts arm
posterior: extends and laterally rotates arm

5

Attachments of supraspinatus

Proximal: supraspinous fossa of scapula
Distal: superior facet of greater tubercle of humerus (via strong flat tendon)

6

Innervation of supraspinatus

suprascapular nerve (C5, C6)

7

Action of supraspinatus

initiates (first 15 degrees) and assists deltoid in abduction of arm and acts with rotator cuff

8

Attachments of infraspinatus

Proximal: infraspinous fossa of scapula
Distal: middle facet of greater tubercle of humerus

9

Innervation of infraspinatus

suprascapular nerve (C5, C6)

10

Action of infraspinatus

laterally rotates arm and helps hold humeral head in glenoid cavity of scapula, acting with rotator cuff

11

Action of teres minor

laterally rotates arm and acts with rotator cuff

12

Attachments of teres minor

Proximal: middle part of lateral border of scapula
Distal: inferior facet of greater tubercle of humerus

13

Innervation of teres minor

axillary nerve (C5, C6)

14

Attachments of teres major

Proximal: posterior surface of inferior angle of scapula
Distal: medial lip of intertubercular sulcus of humerus

15

Innervation of teres major

lower subscapular nerve (C5, C6)

16

Action of teres major

adducts and medially rotates arm at shoulder

17

Attachments of subscapularis

Proximal: subscapular fossa
Distal: lesser tubercle of humerus

18

Innervation of subscapularis

upper and lower subscapular nerves (C5, C6)

19

Action of subscapularis

medially rotates arm, helps hold head of humerus in glenoid cavity (part of rotator cuff), adducts arm

20

Rotator cuff muscles

SITS - supraspinatus, infraspinatus, teres minor, subscapularis

21

Scapulohumeral muscles

deltoid
teres major
rotator cuff muscles (supraspinatus, infraspinatus, teres minor, subscapularis)

22

Pectoral girdle joints

sternoclavicular (SC) joint
acromioclavicular (AC) joint
glenohumeral joint

23

Sternoclavicular joint

saddle joint
ONLY bony attachment of upper extremity to axial skeleton
strong ligaments-->clavicle fractures before tear

24

Acromioclavicular joint

plane joint
lesser mobility
site of shoulder separations

25

Glenohumeral joint

ball-and-socket joint
MOST mobile joint in body
labrum and bursae!
no inferior reinforcement
site of shoulder dislocations (usually inferiorly)

26

Site of shoulder dislocations

glenohumeral joint (usually inferiorly)

27

Site of shoulder separations

acromioclavicular joint

28

Blood supply of deltoid

posterior circumflex humeral artery (mostly, also: anterior circumflex humeral, deltoid branch of thoracoacromial, and profunda brachii)

29

Blood supply of teres minor

lateral circumflex humeral artery + circumflex scapular artery

30

Blood supply of teres major

thoracodorsal artery

31

Blood supply of supraspinatus

suprascapular artery

32

Blood supply of infraspinatus

suprascapular artery

33

Blood supply of subscapularis

subscapular artery