Blood and nerve supply to the shoulder region

Question 1

What is the blood supply to the shoulder region?

Answer 1

Rich blood supply

Scapula anastomosis -> continuous supply of blood during movement -> from subclavian + axillary arteries.

Question 2

Outline the scapula anastomosis

Answer 2

Subclavian -> thyrocervical trunk -> suprascapular anastomosis with axillary branches.
Subscapular branches + dorsal scapular anastomoses with branches from suprascapular.

Question 3

What is the nerve supply to the shoulder?

Answer 3

Brachial plexus -> suprascapular nerve -> supraspinatus + infraspinatus.
Posterior cord:
upper/lower subscapular nerves -> subscapularis, teres major.
thoracodorsal nerve -> latissimus dorsi.
terminates as: radial -> triceps brachi,
axillary -> deltoid + teres minor

Question 4

What is the location of the cords of the brachial plexus?

Answer 4

Within axilla, below pectoralis minor

Question 5

What are the borders of the quadrangular space?

Answer 5

Superior -> teres minor
Inferior -> teres major
Medial -> long head of triceps
Lateral -> humerus

Question 6

What is the clinical significance of the quadrangular space?

Answer 6

Fracture of surgical neck can damage nerve + vessel -> can prevent abduction

Question 7

What does the axillary nerve innervate and what is its location?

Answer 7

Deltoid, teres minor, badge area
Quadrangular space (+ post. circumflex humeral artery).

Question 8

What does the lateral cord give rise to/terminate and what does its branch innervate?

Answer 8

Musculocutaneous (arm flexors), median nerves.

Lateral pectoral nerve -> pectoralis major.

Question 9

What does the medial cord give rise to/terminate and what does its 3 branches innervate?

Answer 9

Median + ulnar nerves
Medial pectoral nerve -> pectoralis major/minor,
medial cutaneous nerves -> arm + forearm.