M1 – Muscled Arm See diagram on next page 1. tendinous junction 38. brachial artery 2. dorsal interosseous muscles of hand 39. humerus 3. radial nerve 40. lateral epicondyle of humerus 4. radial artery 41. tendon of flexor carpi radialis muscle 5. extensor retinaculum 42. median nerve 6. abductor pollicis brevis muscle 43. flexor retinaculum 7. extensor carpi radialis brevis muscle 44. tendon of palmaris longus muscle 8. extensor carpi radialis longus muscle 45. common palmar digital nerves of 9. brachioradialis muscle median nerve 10. brachialis muscle 46. flexor pollicis brevis muscle 11. deltoid muscle 47. adductor pollicis muscle 12. supraspinatus muscle 48. lumbrical muscles of hand 13. scapular spine 49. tendon of flexor digitorium 14. trapezius muscle superficialis muscle 15. infraspinatus muscle 50. superficial transverse metacarpal 16. latissimus dorsi muscle ligament 17. teres major muscle 51. common palmar digital arteries 18. teres minor muscle 52. digital synovial sheath 19. triangular space 53. tendon of flexor digitorum profundus 20. long head of triceps brachii muscle muscle 21. lateral head of triceps brachii muscle 54. annular part of fibrous tendon 22. tendon of triceps brachii muscle sheaths 23. ulnar nerve 55. proper palmar digital nerves of ulnar 24. anconeus muscle nerve 25. medial epicondyle of humerus 56. cruciform part of fibrous tendon 26. olecranon process of ulna sheaths 27. flexor carpi ulnaris muscle 57. superficial palmar arch 28. extensor digitorum muscle of hand 58. abductor digiti minimi muscle of hand 29. extensor carpi ulnaris muscle 59. opponens digiti minimi muscle of 30. tendon of extensor digitorium muscle hand of hand 60. superficial branch of ulnar nerve 31. head of unla 61. dorsal metatarsal arteries 32. tendon of extensor digiti minimi 62. head of metacarpal bone muscle 63. dorsal digital arteries of hand 33. dorsal branch of ulnar nerve 64. dorsal digital nerves of fingers 34. coracobrachialis muscle 65. tendon of extensor indicis muscle 35. axillary nerve 66. body of metacarpal bone 36. posterior circumflex humeral artery 67. tendon of extensor pollicis muscle 37. quadrangular space 3B – M11 Muscled Arm Page 1 of 1 M1 – Muscled Arm 3B – M11 Muscled Arm Page 2 of 2 .