Posterior Shoulder and Posterior Compartment of the Arm

Question 1

Deltoid (Anterior, Lateral, Posterior Fibers)
Blood Supply:
Innervation:
Action:

Answer 1

Blood Supply: Posterior Circumflex Humoral Artery
Innervation: Axillary Nerve
Action: Medial: Medially rotate, flex, and adduct arm.
Lateral: Abduct arm. Posterior: Laterally rotate, extend and adduct arm

Question 2

Teres Major
Blood Supply:
Innervation:
Action:

Answer 2

Blood Supply: Circumflex scapular artery
Innervation: Subscapular nerve
Action: Medially rotate, extend, and adduct arm

Question 3

Teres Minor
Blood Supply:
Innervation:
Action:

Answer 3

Blood Supply: Circumflex scapular artery, posterior circumflex humeral artery
Innervation: Axillary nerve
Action: Laterally rotate and adduct arm. Weak at this

Question 4

Infraspinatus
Blood Supply:
Innervation:
Action:

Answer 4

Blood Supply: Circumflex scapular artery, subscapular artery
Innervation: Suprascapular nerve
Action: Laterally rotate arm

Question 5

Supraspinatus
Blood Supply:
Innervation:
Action:

Answer 5

Blood Supply: Suprascapular artery
Innervation: suprascapular nerve
Action: Abduct arm

Question 6

Triceps Brachii (Long, Lateral , Medial head)
Blood Supply:
Innervation:
Action:

Answer 6

Blood Supply: Deep brachial artery
Innervation: Radial nerve
Action: Long: Extend and adduct arm, extend forearm. Medial, Lateral: Extend forearm

Question 7

The posterior circumflex humeral artery travels with what nerve in the quadrangular space?

Answer 7

Axillary nerve

Question 8

What are the contents of the triangular interval?

Answer 8

Radial nerve and deep brachial artery

Question 9

Name the muscles of the rotator cuff.

Answer 9

superspinatus, infraspinatus, teres minor, subscapularis, (SITS)

Question 10

The suprascapular nerve travels underneath what ligament?

Answer 10

Superior Transverse Scapular Ligament

Question 11

What is the common action of the three heads of the triceps brachii muscle?

Answer 11

Extend arm. But the long one specifically adducts

Question 12

Attachment of the 3 heads of the triceps

Answer 12

Olecranon process = distal. For medial and Lateral head: lateral and medial to radial groove of humerous. For long head: Infraglenoid tubercle of scapula