1. Lab 4 – 3.2: Shoulder

2. Deltoid
Origin: spine of scapula, acromion, anterior lateral 1/3 clavicle
Insertion: Deltoid tuberosity (humerus)
Innervation: Axillary Nerve (C5,C6)
Function: abduction of arm

3. Deltoid (cont)
Note: posterior humeral circumflex artery supplies deltoid

4. Supraspinatus Origin: supraspinous fossa
Insertion: Greater tubercle of the humerus (superior surface)
Innervation: Suprascapular nerve (C5,C6)
Function: abduction of arm at glenohumeral joint
Greater tubercle

5. Supraspinatus (cut) Note: Superior transverse scapular ligament
Suprascapular Nerve (inferior to ligament)
Suprascapular artery (superior to ligament)

6. Suprascapular Artery
Right Subclavian artery  thyrocervical trunk  suprascapular artery
Supplies suprascapular muscle and glenohumeral joint
Greater tubercle

7. Infraspinatus Origin: medial 2/3 of intraspinous fossa
Insertion: Greater tubercle of the humerus (middle posterior surface)
Innervation: Suprascapular nerve (C5,C6)
Function: lateral rotation of arm at glenohumeral joint
Greater tubercle

8. Circumflex scapular Artery
Branch from suprascapular artery – supplies infraspinatus muscle and glenohumeral joint
Greater tubercle

9. Suprascapular Vein
Drains posterior scapular region
Greater tubercle

10. Teres Minor Muscle Origin: lateral border of the scapula
Insertion: greater tubercle of the humerus
Innervation: Axillary nerve
Function: Rotator Cuff Muscle lateral rotation of the arm at the glenohumeral joint
Gray’s anatomy for students (GS): pg. 656

11. Teres Major Muscle Origin: Scapula (inferior angle and lateral border)
Insertion: humerus (medial lip of the intertubercular sulcus)
Innervation: lower subscapular nerve
Function:
medial rotation of arm
extension of the arm
Adduction of the arm
GS: pg. 679

12. Long head of the triceps brachii
Origin: scapula (infraglenoid tubercle)
Insertion: olecranon of ulna
Innervation: Radial nerve
Function:
extension of the forearm
Accessory adductor/extensor of the arm

13. Serratus anterior Origin: lateral surface of ribs 1-9
Insertion: scapula (medial border)
Innervation: long thoracic nerve
Function:
Abduction of the scapula
Medial rotation of scapula
Keeps medial border and inferior angle of scapula opposed to thoracic wall
GS: pg. 689

14. Pectoralis Major *active during forced inspiration Origin:
medial clavicle
sternum, costal cartilages 1-7,
aponeurosis of external abdominal oblique muscle
Insertion: intertubercular sulcus of humerus (lateral lip)
Innervation:
Lateral pectoral nerve (C5-7)
Medial pectoral nerve (C8-T1)
Function: Adduction, medial rotation, and flexion of humerus (shoulder joint)
*active during forced inspiration

15. Pectoralis Minor Origin: ribs 3-5
Insertion: Coracoid process of scapula
Innervation: Medial pectoral nerves
Function: Depresses tip of shoulder; protracts scapula
Active during forced inspiration

16. Deltopectoral Triangle
Also known as “clavipectoral” triangle
Bordered by pectoralis major muscle, deltoid muscle, and clavicle
Passageway for cephalic vein
Greater tubercle

17. Axillary Vein
Drainage: Pectoral, shoulder, and scapular regions

18. Axillary Nerve
Motor
Innervates the deltoid muscle

19. Latissimus Dorsi
Origin: Spinous processes of TVII through LV and sacrum, iliac crest, ribs X–XII
Insertion: Humerus (floor of intertubercular sulcus)
Innervation: Thoracodorsal nerve (C6–C8)

20. Latissimus Dorsi
Function: Extends, adducts, and medially rotates humerus

21. Quadrangular Space Location: Shoulder (posterior scapular region)
Boundaries:
Superior boundary: Inferior margin of teres minor
Lateral boundary: Surgical neck of the humerus
Inferior boundary: Superior margin of teres major
Medial boundary: Lateral margin of the long head of the triceps brachii
Function:
Passageway for posterior circumflex humeral artery and vein and axillary nerve
Quadrangular space

22. Triangular Space Location: shoulder (posterior) Boundaries:
Superior boundary: inferior teres minor muscle
Inferior boundary: superior teres major muscle
Lateral boundary: medial long head of triceps brachii muscle
Function:
Passageway for circumflex scapular artery and vein

23. Deltoid

24. Axillary Nerve

25. Supraspinatus

26. Infraspinatus

27. Teres Minor Muscle
Gray’s anatomy for students (GS): pg. 656

28. Teres Major Muscle
GS: pg. 679

29. Long head of the triceps brachii

30. Serratus anterior
GS: pg. 689

31. Pectoralis Major

32. Pectoralis Minor

33. Latissimus Dorsi

34. Arteries and Nerves 2 1 3 4