AXILLARY ARTERY AND BRACHIAL PLEXUS

1. AXILLARY ARTERY AND BRACHIAL PLEXUS Valentin C. Dones III, MSPT, PTRP, COMT, DMS, IMPT Masters of Science in Orthopedic Physical Therapy Certified Dorn Teacher Certified Dorn Specialist Certified in Orthopedic Manual Therapy Mulligan Practitioner Functional Fascial Taping Practitioner Integrated NeurMuscular Taping Therapist

2. AXILLA • Floor • Fascia and a dome of skin • Anterior axillary fold > posterior axillary fold • Continuous with the anterior compartment of the arm

3. Contents of the Axilla • Proximal parts of biceps brachii and coracobrachialis • Axillary process of the breast • Collections of lymph nodes • Major vessels and nerves

4. Biceps Brachii • Origin • Short head: apex of coracoid process • Long head: Supraglenoid tubercle • Insertion • Radial tuberosity in the forearm • Action • Flexor of the forearm • Supinator of the forearm • Accessory flexor of GHJ • Prevents superior movement of the humerus on the glenoid cavity • Innervation • Musculocutaneous nerve

5. Coracobrachialis • Origin • Apex of the coracoid process • Insertion • Small linear roughening on the medial aspect of the humerus, midshaft • Action • Flexes the arm at the GHJ • Innervation • Musculocutaneous nerve

6. Axillary artery • Subclavian artery  lateral border of rib 1  axillary artery  inferior margin of teres major  brachial artery • Pectoralis minor  3 parts of the axillary artery

7. Axillary artery • First part • Superior thoracic artery • Second part • Thoraco-acromial artery • Lateral thoracic artery • Third part • Subscapular artery • Anterior circumflex humeral artery • Posterior circumflex humeral artery

8. Superior thoracic artery • From the anterior surface of the first part of the axillary artery • Upper regions of the medial and anterior axillary walls

9. Thoraco-acromial artery • From the anterior surface of the second part of the axillary artery • Pierces the clavipectoral fascia • Four branches • Pectoral • Pierces the clavipectoral fascia • Deltoid • Accompanies the cephalic vein • Clavicular • Acromial

10. Lateral Thoracic Artery • Posterior to the inferior margin of pectoralis minor • Supplies the medial and anterior walls • Supplies breast

11. Subscapular artery • Largest branch of the axillary artery • To the posterior wall of the axilla in the posterior scapular region • From the posterior surface of the third part of the axillary artery • Follows inferior margin of the subscapular artery

13. Subscapular artery • Circumflex Scapular Artery • Enters the infraspinous fossa • Thoracodorsal Artery • Follows the lateral border of the scapula to the inferior angle • Vascular supply of the posterior and medial walls of the axilla

15. Anterior Circumflex Humeral Artery • Small compared to the posterior circumflex humeral artery • Passes anterior to the surgical neck of the humerus

17. Posterior Circumflex Humeral Artery • From the lateral surface of the third part of the axillary artery • Leaves the quadrangular space with the axillary nerve

18. Axillary Vein • Begins at the lower border of the teres major • Continuation of the basilic vein • Drains the posteromedial surface of the hand • Penetrates the deep fascia in the middle of the arm • Axillary vein  subclavian vein at lateral border of rib 1 • Tributaries • Brachial veins • Cephalic vein

19. Cephalic Vein • Drains the lateral and posterior parts of the hand, the forearm, and the arm • Enters the clavipectoral triangle

20. Brachial Plexus • Anterior rami of C5-C8, T1 • Roots, trunks, divisions and cords • Proximal parts of the brachial plexus are posterior to the subclavian artery • More distal regions of the plexus surround the axillary artery

21. Roots • Receives gray rami communicantes • In the posterior triangle of the neck • Between the anterior and middle scalenes • Superior and posterior to the subclavian artery

22. Trunks • Superior trunk – C5 and C6 • Middle trunk – C7 root • Inferior trunk – C8 – T1 • Lies on rib 1 posterior to the subclavian artery

24. Divisions • Anterior • Posterior • Anterior divisions  peripheral nerves  anterior compartments of the arm and forearm • Posterior divisions  peripheral nerves  posterior compartments

26. Cords • Related to the second part of the axillary artery • Lateral cord • Union of upper and middle trunks • Lateral to the axillary artery (2nd part) • Medial cord • Continuation of the anterior division of the inferior trunk • Medial to the axillary artery (2nd part)

28. Cords • Posterior cord • Posterior to the axillary artery (2nd part) • Union of all three posterior divisions

29. Branches of the Roots

30. Dorsal Scapular Nerve • Originates from C5 • Pierces the middle scalene • Travels the medial border of the scapula • Innervates • Rhomboid major • Rhomboid minor

32. Long Thoracic Nerve • Anterior rami of C5 to C7 • Down the medial wall of the axilla • On the superficial aspect of the serratus anterior muscle

33. LONG THORACIC NERVE • C5, C6, C7 • Enters the axilla by passing down over the lateral border of the first rib behind the axillary vessels and brachial plexus • Descends over the lateral surface of the serratus anterior, which it supplies

35. Suprascapular Nerve • C5 and C6 • From the superior trunk of the brachial plexus • Passes laterally through the posterior triangle of the brachial plexus • Through the suprascapular foramen  posterior scapular region • Innervates • Supraspinatus • Infraspinatus

36. Nerve to the subclavius • From the superior trunk of the brachial plexus • Passes anteroinferiorly over the subclavian artery and vein • Innervates the subclavius muscle

37. Lateral Pectoral Nerve • Most proximal • Penetrates the pectoral branch of the thoraco-acromial artery • Innervates the pectoralis major

39. Musculocutaneous nerve • Large terminal branch of the lateral cord • Penetrates the coracobrachialis muscle • Passes between the biceps brachii and brachialis muscles • Lateral cutaneous nerve of the forearm

41. Lateral Root of the Median Nerve • Largest terminal branch of the lateral cord • Joins the medial root of the medial cord  Median Nerve

42. Medial Pectoral Nerve • Supplies the pectoralis minor • Supplies the pectoralis major • Most proximal branch • Passes in between the axillary artery and axillary vein

43. Medial cutaneous nerve of the arm • Medial brachial cutaneous nerve • Supplies the skin over the medial side of the arm • In the axilla, communicates with the intercostobrachial nerve (T2)

44. Medial Cutaneous Nerve of the Forearm • Medial antebrachial cutaneous nerve • Just distal to the origin of the medial cutaneous nerve of the arm • Gives off a branch to the skin over the biceps brachii muscle • Penetrates the deep fascia with the basilic vein

45. Medial Root of the Median Nerve • With the lateral root forms the lateral cord of the brachial plexus • Median nerve is formed anterior to the third part of the axillary artery

46. Ulnar Nerve • Large terminal branch of the medial cord

47. Median Nerve • Formed anterior to the third part of the axillary artery • Union of lateral and medial roots • Passes anterior to the brachial artery • Innervates • Thenar muscles • Two lateral lumbricals • Palmar surface of the lateral three and ½ digits and over the lateral side of the palm and middle of the wrist

48. Median Nerve • M over the third part of the axillary artery • Musculocutaneous nerve • Lateral root of the median nerve • Medial root of the median nerve • Ulnar nerve

49. Median Nerve • M over the third part of the axillary artery • Musculocutaneous nerve piercing the coracobrachialis muscle

50. Branches of the Posterior Cord • Superior subscapular nerve • Thoracodorsal nerve • Inferior subscapular nerve • Axillary nerve • Radial nerve