1. Shoulder region muscles

2. Coracobrachialis
Adduction of the shoulder & flexion.

3. Pectoralis Major
The first action is flexion of the humerus, Secondly, it adducts the humerus. Thirdly, it rotates the humerus medially. Finally it aids in deep inspiration

4. Subscapularis
Internal rotation of the shoulder

5. Deltoid
Abduction of shoulder

6. Infraspinatus
External rotation

7. Adduction of scapula
Teres Major

8. Teres Minor
The infraspinatus and teres minor attach to head of the humerus; as part of the rotator cuff they help hold the humeral head in the glenoid cavity of the scapula. They work in tandem with the posterior deltoid to externally (laterally) rotate the humerus, as well as perform transverse abduction, extension and transverse extension.

9. Supraspinatus
Abduction of the shoulder

10. Coracobrachialis
Pect. Major
Subscapularis
Deltoid

11. Supraspinatus
Teres Major
Infraspinatus
Teres Minor

12. Practice List the muscles that do flexion of the shoulder
Coracobrachialis
Pectoralis major (upper to part)
Anterior Deltoid
Biceps
List the muscles that do extension of the shoulder
Latissimus dorsi
Teres major
Posterior deltoid
Pectoralis major (lower fibers to neutral)

13. Practice List the muscles that do adduction of the shoulder
Pectoralis major (lower and upper below 90°)
Coracobrachialis
Latissimus dorsi
Teres major
List the muscles that do abduction of the shoulder
Deltoid (all sections)
Supraspinatus
Pectoralis major (upper past 90°)

14. Practice List the muscles that do internal rotation of the shoulder
Subscapularis
Latissimus dorsi
Teres major
Anterior deltoid
Pect. major
List the muscles that do external rotation of the shoulder
Infraspinatus
Teres minor
Posterior deltoid

15. Questions What muscle works closely with the anterior deltoid?
Pectoralis major
What muscle is involved in any lifting movements?
Deltoid
What is the major (strongest) extensor muscle?
Latissimus Dorsi
Name the four rotator cuff muscles.
Subscapularis, Supraspinatus, Infraspinatus, and Teres minor.
What muscle works closely with the infraspinatus?
Teres minor

16. Axillary region

17. The axilla, or armpit, is a pyramidshaped space between the upper part of the arm and the side of the chest. Realize that the upper end, or apex, is directed into the root of the neck and is bounded anteriorly by the clavicle, posteriorly by the upper border of the scapula, and medially by the outer border of the first rib. The lower end, or base, is bounded anteriorly by the anterior axillary fold (formed by the lower border of the pectoralis major muscle), behind by the posterior axillary fold (formed by the tend of latissimus dorsi and the teres major muscle), and medially by the chest wall.

20. Walls of the Axilla. Identify the structures forming the walls of the axilla:

21. Anterior wall. This is formed by the pectoralis major, pectoralis minor, clavipectoral fascia, and subclavius muscle

24. Posterior wall. From above downward this wall is formed by the subscapularis, latissimus dorsi, and the teres major muscles.

26. Medial wall. This is formed by the upper four or five ribs and the intercostal spaces covered by the serratus anterior muscle.

28. Lateral wall. This is formed by the coracobrachialis and biceps muscles in the bicipital groove of the humerus.

30. Axillary Sheath. The axillary artery (but not the vein) and the brachial plexus are enclosed in a fascial sheath derived from the prevertebral layer of deep cervical fascia in the neck.

31. Axillary Artery. This commences at the outer border of the first rib as a continuation of the subclavian artery. Having passed through the axilla, it becomes the brachial artery at the lower border of the teres major muscle. It is arbitrarily divided into three parts by the pectoralis minor muscle that crosses it anteriorly.

33. Brachial Plexus.

34. Brachial plexus
The brachial plexus is divided into Roots, Trunks, Divisions, Cords, and Branches. There are five "terminal" branches and numerous other "pre-terminal" or "collateral" branches that leave the plexus at various points along its length.
The five roots are the five anterior rami of the spinal nerves, after they have given off their segmental supply to the muscles of the neck.
These roots merge to form three trunks:
"superior" or "upper" (C5-C6)
"middle" (C7)
"inferior" or "lower" (C8-T1)

35. Brachial plexus Each trunk then splits in two, to form six divisions:
anterior divisions of the upper, middle, and lower trunks
posterior divisions of the upper, middle, and lower trunks
These six divisions will regroup to become the three cords. The cords are named by their position with respect to the axillary artery.
The posterior cord is formed from the three posterior divisions of the trunks (C5-T1)
The lateral cord is the anterior divisions from the upper and middle trunks (C5-C7)
The medial cord is simply a continuation of the anterior division of the lower trunk (C8-T1)
The branches are shown in the following diagram

39. Thank You