24: UE Myology: Trunk

Question 1

Pec major O and I

Answer 1

O: medial clavicle, anterior sternum, costal cartilages 1-6
I: intertubercular groove of humerus

Question 2

Pect major A

Answer 2

Adduct, medially rotates, flexes and extends humerus, protracts and depresses scapula

Question 3

Pec major and minor N

Answer 3

Pec major: lateral and medial pectoral N

Pec minor: medial pectoral N

Question 4

Which muscle is pierced by the medial pectoral N

Answer 4

Pec minor

Question 5

Pec minor O and I

Answer 5

O: medial aspect ribs 3-5
I: coracoid process of scapula

Question 6

Pec minor A

Answer 6

Stabilizes scapula by protracting + depressing against thoracic wall

Question 7

Subclavius O and I

Answer 7

O: upper border 1st rib, 1st costal cartilage
I: inferior clavicle

Question 8

Subclavius A

Answer 8

Positions and depresses clavicle

Question 9

Subclavius N

Answer 9

N to subclavius

Question 10

Serratus anterior O and I

Answer 10

O: lateral external ribs 1-8
I: medial border of scapula

Question 11

Serratus anterior A

Answer 11

Protracts scapula, stabilizes against thoracic wall, rotates glenoid cavity superiorly

Question 12

Serratus anterior N and blood supply

Answer 12

N: long thoracic N
BS: lateral thoracic A

Question 13

What does injury to long thoracic nerve cause?

Answer 13

Winging of the scapula away from thoracic wall -> abduction of upper limb becomes difficult

Question 14

Deltoid O and I

Answer 14

O: lateral clavicle, scapular spine, acromion
I: deltoid tuberosity of humerus

Question 15

Deltoid A: three parts

Answer 15

Anterior portion: flex, medially rotate
Middle: abduct humerus
Posterior: extend, laterally rotate humerus

Question 16

Deltoid N

Answer 16

Axillary N

Question 17

Subscapularis O and I

Answer 17

O: medial aspect of subscapular fossa
I: lesser tubercle of humerus

Question 18

Subscapularis A

Answer 18

Medially rotate and adduct humerus

Question 19

Subscapularis N

Answer 19

Upper subscapular N, lower subscapular N

Question 20

Four rotator cuff muscles and their action

Answer 20

Subscapularis, supraspinatus, infraspinatus, teres minor: hold humeral head in glenoid cavity

Question 21

Supraspinatus O and I

Answer 21

O: supraspinatus fossa of scapula
I: greater tubercle of humerus

Question 22

Supraspinatus A

Answer 22

Abducts humerus

Question 23

Supraspinatus and infraspinatus N

Answer 23

Suprascapular N

Question 24

Infraspinatus O and I

Answer 24

O: infraspinous fossa
I: greater tubercle of humerus

Question 25

Infraspinatus A

Answer 25

Laterally rotate humerus

Question 26

Teres minor O and I

Answer 26

O: middle lateral border of scapula
I: greater tubercle of humerus

Question 27

Teres minor A

Answer 27

Laterally rotate humerus

Question 28

Teres minor N

Answer 28

Axillary N

Question 29

Most commonly injured rotator cuff muscle

Answer 29

Supraspinatus

Question 30

Teres major O and I

Answer 30

O: posterior aspect of inferior angle of scapula
I: medial edge of intertubercular groove of humerus

Question 31

Teres major A

Answer 31

Adduct, medially rotate humerus

Question 32

Teres major N

Answer 32

Lower subscapular N