W126 Shoulder Anatomy Flashcards
What is the arterial supply to the glenohumeral joint?
- anterior and posterior circumflex humeral arteries,
- the suprascapular artery
What nerves innervate the glenohumeral (shoulder) joint?
- axillary,
- suprascapular,
- lateral pectoral nerves
What nerve roots do the nerves that innervate the shoulder derive from?
C5 and C6 of brachial plexus
What upper brachial plexus injury will affect shoulder action?
Erb’s palsy
Good old Erb
Muscles for extension?
posterior deltoid,
latissimus dorsi,
teres major.
Describe muscles involved in abduction of shoulder.
Firstly, suprapinatus.
Then anterior deltoid.
Then scapula must rotate and involve serrateous anterior and trapezius muscles. (Past 90 degrees).
What is the name of the fibrocartilaginous ridge surrounding the glenoid cavity?
Glenoid labrum
What are the 4 rotator cuff muscles?
What’s occurin’ ? Describe.
Anterior dislocation of the humerous.
What nerves can anterior shoulder dislocation effect?
Axillary (most likely)
Radial (less often)
What would you see in a person whose axillary nerve had been disturbed by a dislocation?
Paralysis of the deltoid, and loss of sensation over regimental badge area.
What is the most characteristic sign of rotator cuff tendonitis?
“The painful arc” - pain part way through abduction.
(Where the affected area comes into contact with the acromion).
Name 2 superficial extrinsic muscles of the shoulder.
Trapezius
Latissimus dorsi
Describe the innervation of the Trapezius muscle?
Motor innervation is from the accessory nerve.
It also receives proprioceptor fibres from C3 and C4 spinal nerves.
What is the most common cause of accessory nerve damage?
Iatrogenic
How can you test for a working accessory nerve?
Ask the patient to shrug their shoulders.
What is the innervation of the latissimus dorsi?
Thoracodorsal nerve
What are the 3 deep extrinsic muscles of the shoulder?
- levator scapulae
- rhomboid minor
- rhomboid major
Innervation of levator scapulae, rhomboid minor and rhomboid major?
Dorsal scapular nerve.
What are the 6 intrinsic shoulder muscles?
- deltoid,
- teres major,
- supraspinatus,
- infraspinatus,
- subscapularis,
- teres minor
What are the missing labels?
What innervates teres major?
Lower subscapular nerve
What innervates the infra and supra spinatous muscles?
Suprascapula nerve
What innervates teres minor?
Axillary nerve
What are the borders of the axilla?
What are the contents of the axilla region?
What is thoracic outlet syndrome?
In the axilla apex, the vessels and nerves become compressed between the bones.
What are common causes of thoracic outlet syndrome?
- Trauma (e.g fractured clavicle) and
- Repetitive actions (seen commonly in occupations that require lifting of the arms)
Presentation of thoracic outlet syndrome?
- Pain in the affected limb, (where the pain is depends on what nerves are affected),
- tingling,
- muscle weakness and
- discolouration.
What nerve, when damaged, causes winging?
Long thoracic nerve
