Proximal upper limb

Question 1

What are the 6 intrinsic muscles of the shoulder?

Answer 1

Deltoid
Teres major

Rotator cuff muscles: Supraspinatus, infraspinatus, subscapularis, teres minor

Question 2

What are the main functions of deltoid and teres major?

What innervates these structures?

Answer 2

Deltoid = major abductor of the arm
Axillary nerve

Teres major = Adducts + extends shoulder, medially rotates arm
Lower subscapular nerve

Question 3

What is the key function of the rotator cuff muscles?

What provides innervation to these muscles?

Answer 3

Stabilise the humeral head in the glenoid fossa so there is stability of the glenohumeral joint

Supraspinatus + infraspinatus = subscapular nerve
Subscapularis = upper + lower subscapular
Teres minor = axillary nerve

Question 4

What are the extrinsic muscles of the shoulder?

What innervates these muscles?

Answer 4

Superficial layer = Trapezius ( accessory nerve) + lattisimus dorsi ( thoracodorsal nerve)

Deep layer = Levator scapulae, rhomboid major + minor
Innervation = dorsal scapular nerve

Question 5

What are the 2 compartments of the arm?

Answer 5

Anterior + posterior

Question 6

What are the muscles of the anterior arm?

What is their common function?

Answer 6

Biceps brachii
Brachialis
Coracobrachialis

Arm flexion

Question 7

What is the blood and nerve supply to the anterior arm?

Answer 7

Brachial artery

Musculocutaneous nerve

Question 8

What are the muscles of the posterior arm?

What is their common function?

Answer 8

Triceps brachii

Extension of the arm

Question 9

What is the blood and nerve supply to the posterior arm?

Answer 9

Profunda brachii artery

Radial nerve