W126 Shoulder Anatomy

Question 1

What is the arterial supply to the glenohumeral joint?

Answer 1

• anterior and posterior circumflex humeral arteries,
• the suprascapular artery

Question 2

What nerves innervate the glenohumeral (shoulder) joint?

Answer 2

• axillary,
• suprascapular,
• lateral pectoral nerves

Question 3

What nerve roots do the nerves that innervate the shoulder derive from?

Answer 3

C5 and C6 of brachial plexus

Question 4

What upper brachial plexus injury will affect shoulder action?

Answer 4

Erb’s palsy

Good old Erb

Question 5

Muscles for extension?

Answer 5

posterior deltoid,

latissimus dorsi,

teres major.

Question 6

Describe muscles involved in abduction of shoulder.

Answer 6

Firstly, suprapinatus.

Then anterior deltoid.

Then scapula must rotate and involve serrateous anterior and trapezius muscles. (Past 90 degrees).

Question 7

What is the name of the fibrocartilaginous ridge surrounding the glenoid cavity?

Answer 7

Glenoid labrum

Question 8

What are the 4 rotator cuff muscles?

Answer 8

Question 9

What’s occurin’ ? Describe.

Answer 9

Anterior dislocation of the humerous.

Question 10

What nerves can anterior shoulder dislocation effect?

Answer 10

Axillary (most likely)

Radial (less often)

Question 11

What would you see in a person whose axillary nerve had been disturbed by a dislocation?

Answer 11

Paralysis of the deltoid, and loss of sensation over regimental badge area.

Question 12

What is the most characteristic sign of rotator cuff tendonitis?

Answer 12

“The painful arc” - pain part way through abduction.

(Where the affected area comes into contact with the acromion).

Question 13

Name 2 superficial extrinsic muscles of the shoulder.

Answer 13

Trapezius

Latissimus dorsi

Question 14

Describe the innervation of the Trapezius muscle?

Answer 14

Motor innervation is from the accessory nerve.

It also receives proprioceptor fibres from C3 and C4 spinal nerves.

Question 15

What is the most common cause of accessory nerve damage?

Answer 15

Iatrogenic

Question 16

How can you test for a working accessory nerve?

Answer 16

Ask the patient to shrug their shoulders.

Question 17

What is the innervation of the latissimus dorsi?

Answer 17

Thoracodorsal nerve

Question 18

What are the 3 deep extrinsic muscles of the shoulder?

Answer 18

1. levator scapulae
2. rhomboid minor
3. rhomboid major

Question 19

Innervation of levator scapulae, rhomboid minor and rhomboid major?

Answer 19

Dorsal scapular nerve.

Question 20

What are the 6 intrinsic shoulder muscles?

Answer 20

1. deltoid,
2. teres major,
3. supraspinatus,
4. infraspinatus,
5. subscapularis,
6. teres minor

Question 21

What are the missing labels?

Answer 21

Question 22

What innervates teres major?

Answer 22

Lower subscapular nerve

Question 23

What innervates the infra and supra spinatous muscles?

Answer 23

Suprascapula nerve

Question 24

What innervates teres minor?

Answer 24

Axillary nerve

Question 25

What are the borders of the axilla?

Answer 25

Question 26

What are the contents of the axilla region?

Answer 26

Question 27

What is thoracic outlet syndrome?

Answer 27

In the axilla apex, the vessels and nerves become compressed between the bones.

Question 28

What are common causes of thoracic outlet syndrome?

Answer 28

• Trauma (e.g fractured clavicle) and
• Repetitive actions (seen commonly in occupations that require lifting of the arms)

Question 29

Presentation of thoracic outlet syndrome?

Answer 29

• Pain in the affected limb, (where the pain is depends on what nerves are affected),
• tingling,
• muscle weakness and
• discolouration.

Question 30

What nerve, when damaged, causes winging?

Answer 30

Long thoracic nerve