Muscles of the Shoulder Flashcards Preview

Anatomy > Muscles of the Shoulder > Flashcards

Flashcards in Muscles of the Shoulder Deck (35):
1

What are the superficial extrinsic shoulder muscles?

Latissimus Dorsi
Trapezius

2

What nerve causes motor innervation of the Trapezius muscle?

The accessory nerve

3

What causes sensory innervation of the Trapezius muscle?

C3 and C4 spinal roots

4

What is the main action of the upper fibres of the Trapezius?

Elevate the scapula and rotate it during abduction of the shoulder

5

What is the main action of the middle fibres of the Trapezius?

Retract the Scapula

6

What is the main action of the lower fibres of the Trapezius?

Pull the Scapula inferiorly

7

How can you test the function of the accessory nerve?

See how the Trapezius muscle functions by asking the patient to elevate the shoulder against resistance.

8

What nerve innervates Latissimus Dorsi?

The thoracodorsal nerve

9

What are the main actions of Latissimus Dorsi?

Extension of the arm at the shoulder
Adduction at the shoulder
Medial rotation of the arm

10

What are the deep extrinsic muscles of the shoulder?

Levator scapulae
Rhomboids

11

What nerve innervates the Levator scapulae?

The Dorsal scapular nerve

12

What are the main actions of the Levator scapulae?

Elevates scapula
Rotates scapula to tilt the Glenohumeral joint inferiorly

13

What are the two Rhomboid muscles?

Rhomboid major
Rhomboid minor

14

What innervates the Rhomboid muscles?

The Dorsal scapular nerve

15

What are the actions of the Rhomboid muscles?

Retracts the scapula
Fix scapula to thoracic wall
Rotates scapula to tilt the Glenohumeral joint inferiorly

16

What are the Scapulohumeral muscles?

Deltoid
Teres major

17

What innervates the Deltoid?

The axillary nerve

18

What is the main action of the anterior fibres of the Deltoid?

Flex the arm at the shoulder

19

What is the main action of the posterior fibres of the Deltoid?

Extend the arm at the shoulder

20

What is the main function of the middle fibres of the Deltoid?

Major abductors of the arm, from 15 degrees onwards

21

What innervates Teres major?

The lower subscapular nerve

22

What are the main actions of the Teres major?

Adductors the shoulder
Medially rotates the arm

23

What are the 4 rotator cuff muscles?

Supraspinatus
Infraspinatus
Teres minor
Subscapularis

24

What is main function of the rotator cuff muscles?

Add stability to the glenohumeral joint

25

What innervates the Supraspinatus muscles?

Suprascapular nerve

26

What is the main action of the Supraspinatus muscle?

First 15 degrees abduction of the arm
Aids the Deltoid for the rest

27

What innervates the Infraspinous muscle?

Suprascapular nerve

28

What is the main action of the Infraspinous muscle?

Lateral rotation of the arm

29

What innervates the Subscapularis muscle?

Upper and lower Subscapular nerve

30

What is the main action of the Subscapularis muscle?

Medially rotates the arm

31

What innervates Teres minor?

The axillary nerve

32

What is the main action of Teres minor?

Lateral rotation of the arm

33

What is a sign of rotator cuff tendonitis?

Painful arc syndrome

34

What is painful arc syndrome?

Pain in the middle of abduction of the arm due to the affected area coming into contact with the acromion

35

What is the pathology of rotator cuff tendonitis?

Degenerative changes in the subacromial bursa and supraspinatus tendon due to repetitive use.