UNIT 1: scapulohumeral muscles

Question 1

what are the six scapulohumeral muscles?

Answer 1

• deltoid
• subscapularis
• supraspinatus
• infraspinatus
• teres minor
• teres major
  (coraco-brachialis)

Question 2

which four muscles form the rotator cuff?

Answer 2

SITS - converge at humerus to form musculotendinous cuff

• supraspinatus
• infraspinatus
• teres minor
• subscapularis

Question 3

what is the role of the rotator cuff?

Answer 3

works along side the long head of the triceps to prevent humerus sliding out of the glenoid fossa

Question 4

what are the two important tendons in shoulder muscle and where do they arise from?

Answer 4

• long head of biceps = infraglenoid tubercle
• long head of triceps = supraglenoid tubercle
  (passes inside joint capsule and over head of humerus)

Question 5

SUBSCAPULARIS:

1) Where does it arise from?
2) where does its tendon insert?
3) what movement does it produce?`

Answer 5

1) subscapular fossa
2) lesser tubercle of humerus
3) internal rotation/medial rotation part of rotator cuff: holds humerus and glenoid fossa together

Question 6

SUPRASPINATUS:

1) Where does it arise from?
2) where does its tendon insert?
3) what movement does it produce?

Answer 6

1) supraspinous fossa
2) greater tubercle of humerus (superior facet)
3) abduction of humerus

Question 7

INFRASPINATUS:

1) Where does it arise from?
2) where does its tendon insert?
3) what movement does it produce?

Answer 7

1) infraspinous fossa
2) greater tubercle of humerus (middle facet)
3) external/lateral rotation of humerus

Question 8

TERES MINOR:

1) Where does it arise from?
2) where does its tendon insert?
3) what movement does it produce?

Answer 8

1) infraspinous fossa
2) greater tubercle of humerus (inferior facet)
3) external/lateral rotation of humerus

Question 9

TERES MAJOR:

1) Where does it arise from?
2) where does its tendon insert?
3) what movement does it produce?

Answer 9

1) lower lateral border of scapula
2) bicipital groove of humerus
3) adduction of humerus

Question 10

coraco-brachialis:

1) Where does it arise from?
2) where does its tendon insert?
3) what movement does it produce?

Answer 10

1) coracoid process
2) shaft of humerus
3) flex shoulder joint

Question 11

what muscles form the borders of the quadrangular space?

Answer 11

superior: teres minor
inferior: teres major
medial: long head of triceps
lateral: surgical neck of humerus

Question 12

what is contained in the quadrangular space?

Answer 12

axillary nerve and posterior humeral circumflex artery

Question 13

which muscles form the borders of the triangular space?

Answer 13

superior: teres minor
inferior: teres major
lateral: long head of triceps

Question 14

what is contained in the triangular space?

Answer 14

scapular circumflex artery

Question 15

which muscles form the borders of the triangular interval?

Answer 15

superior: teres major
medial: long head of triceps
lateral: humerus

Question 16

what is contained in the triangular interval?

Answer 16

radial nerve and profunda brachii