Functional anatomy of the shoulder

Question 1

Immediately distal to teres major, what does the brachial artery give rise to?

Answer 1

Profunda brachii (deep brachial artery), travels with radial nerve in spiral groove to post. compartment

Question 2

In the proximal arm, where does the median nerve lie in respect to the brachial artery? How does this change at the distal end?

Answer 2

Lateral to brachial artery

Crosses to medial side

Question 3

What is the most mobile joint in the body?

Answer 3

Glenohumeral

Question 4

What reinforces the joint capsule of the shoulder?

Answer 4

Rotator cuff muscles

3 glenohumeral ligaments (superior, middle, inferior) = reduce ant. dislocation risk

Question 5

What is the weakest part of the joint capsule of the shoulder and why?

Answer 5

Inferior as no reinforcement

Question 6

What is the transverse humeral ligament?

Answer 6

Creates tunnel between greater + lesser tuberosities for passage of long head of biceps

Question 7

What is the coraco-acromial ligament?

Answer 7

Tunnel above glenohumeral joint for supraspinatus tendon

Prevent superior dislocation of humerus from FOOSH

Question 8

What are the 2 bursae of the shoulder joint?

Answer 8

SUBACROMIAL BURSA = under acromion, seperates supraspinatous tendon from overlying coraco-acromial ligament/acromion/coracoid process/deltoid

SUBSCAPULAR BURSA = between subscapularis tendon + neck of scapula

Question 9

What is the subacromial space and what 4 things does it contain?
Why is at risk during abduction?

Answer 9

Space between coraco-acromial arch + head of humerus
Subacromial bursa, supraspinatus tendon, joint capsule, long head biceps
Impingement of soft tissues = irritation/inflammation

Question 10

When does the subclavian artery become the axillary artery?

Answer 10

Cross lateral border of 1st rib to enter axilla

Question 11

At the surgical neck of the humerus, what does the axillary artery give off?

Answer 11

Ant. + post. circumflex humeral arteries

Question 12

What does the subscapular artery arise from and what branches does it anastamose with?

Answer 12

3rd part of axillary artery

Branches of suprascapular artery + transverse cervical artery

Question 13

What is the arterial supply of the shoulder joint?

Answer 13

Ant. + post. circumflex humeral arteries

Suprascapular artery

Question 14

When does the axillary artery become the brachial artery?

Answer 14

Inf. border of teres major

Question 15

What are the static stabilisers (at rest) of the glenohumeral joint?

Answer 15

Glenoid labrum
Joint capsule
Glenohumeral ligaments
Extra-capsular ligaments

Question 16

What are the dynamic stabilisers (during motion) of the glenohumeral joint?

Answer 16

Rotator cuff muscles = stability ant., post. + superiorly
Extrinsic muscles crossing shoulder joint = biceps brachii (sup.)/triceps brachii (inf.)/deltoid (sup., ant., post.)/pec. major + coracobrachialis (ant.)