Brachial Plexus

  1. After leaving the spinal roots the brachial plexus follows the blood supply between what  muscles before extending into the upper limb?
    The anterior and middle scalenes.
  2. Name the 4 sections of the B. plexus:
    • 1. Roots
    • 2. Trunks
    • 3. Divisions
    • 4. Cords
  3. The roots come off of what part of the spinal cord?
    Anterior ramii.
  4. What spinal nerves make up the roots of the plexus?
    • C5
    • C6
    • C7
    • C8
    • T1
  5. Which roots make up the superior trunk?
    • C5
    • C6
  6. Which roots make up the middle trunk?
  7. C8 and T1 join to form which trunk?
    Inferior trunk.
  8. Describe what happens to the trunks as we move further down the plexus:
    Each trunk forms an Anterior and Posterior division.
  9. How many anterior divisions are there?
  10. How many posterior divisions are there?
  11. What is a really good way to identify the posterior divisions?
    All 3 posterior divisions merge together, and forming an M.
  12. You are looking at an exposed brachial plexus and you see an M and immediately superior is a V and below there is just an I. What section of the plexus are you looking at.
    The 2 anterior divisions of the upper and middle trunks have come together to form the V, and the anterior division of the lower trunk does not merge with anything and forms an I.
  13. Describe the cords:
    • The Lateral cord is formed by the 2 AD Upper & Middle Trunks (V).
    • The Posterior cord is formed by the 3 PD Upper, Middle and Lower trunks (M).
    • The Medial cord is formed by the continuation of the AD of Lower trunk (I).
  14. Describe the Long Thoracic Nerve:
    • Originates¬†off of roots C5 C6 C7.
    • Points Down.
  15. Which Nerves originate from the roots of the Plexus?
    Long thoracic Nerve.
  16. Describe the Suprascapular Nerve:
    • Originates off of Pre-Upper Division of the Lateral cord (Superior trunk).
    • Points UP.
    • L1
  17. Describe the Lateral Pectoral Nerve:
    • Originates Just after the V on the Lateral cord.
    • Starts by pointing up, and then Arching down.
    • L2
  18. Describe the Musculocutaneous Nerve:
    • Singular Continuation of the Lateral Cord.
    • Points out.
    • L3
  19. Describe the Median Nerve:
    • Branches from Lateral and medial cords intersect to form the Median Nerve.
    • Points out.
    • M5/L4
  20. Describe the Ulnar Nerve:
    • Singular continuation of the Medial Cord.
    • Points out.
    • M4
  21. Describe the Medial Antebrachial Cutanious Nerve:
    • M3
    • Of the 3 Nerves branching from the Medial cord (other than the terminal branches median and ulnar) this one is the most distal.
    • Points out.
  22. Describe the Medial Brachial Nerve:
    • M2
    • Of the 3 Nerves branching from the Medial cord (other than the terminal branches median and ulnar) this one is the middle.
    • Points out.
  23. Describe the Medial Pectoral Nerve:
    • This Descends down just after the I.
    • medial cord.
    • M1
    • Has a short synapse with the Lateral Pectoral Nerve (LPN is Lateral, MPN is Medial)
  24. Describe the Radial Nerve:
    • Singular continuation of the posterior cord.
    • Points Out.
    • P5
  25. Describe the Axillary Nerve:
    • Most Distal branch of the posterior cord.
    • Points up and splits to Deltoids.
    • P4.
  26. Describe Lower subscapular Nerve:
    • 2nd most distal branch on posterior cord.
    • points down.
    • P3
  27. Describe the Thoracodorsal Nerve:
    • 2nd most proximal branch on the posterior cord.
    • Has the Upper and Lower subscapular nerves on both sides.
    • Points down.
    • P2
  28. Describe the Upper Subscapular Nerve:
    • Most proximal branch on the posterior cord. Just after M
    • Points down.
    • P1
  29. What innervates the Serratus Anterior?
    Long thoracic nerve.
  30. What innervates pectoralis minor?
    Medial pectoral nerve.
  31. What innervates the trapezius?
    • Motor comes from the accessory nerve,
    • C3, C4, Pain and proprioception.
  32. What innervates levator scapulae?
    Dorsal Scapular nerve.
  33. What innervates rhomboideus major?
    Dorsal Scapular nerve.
  34. What innervates rhomboideus minor?
    Dorsal scapular.
  35. What innervates pectoralis major?
    Lateral and medial pectoral nerves.
  36. What innervates latissimus dorsi?
    Thoracodorsal nerve.
  37. What innervates the deltoids?
    Axillary nerve.
  38. What innervates the supraspinatus?
  39. What innervates the infraspinatus?
  40. What innervates Teres Minor?
    Axillary nerve.
  41. What innervates teres major?
    Lower scapular.
  42. What innervates the subscapularis?
    Upper and lower subscapular.
  43. What innervates the coracobrachialis?
  44. What innervates biceps brachii?
  45. What innervates the brachialis?
  46. What innervates the brachioradialis?
  47. What innervates the triceps brachii?
  48. What innervates the extensor carpi radialis longus?
  49. What innervates the extensor carpi radialis brevis?
  50. What innervates abductus pollicus longus?
  51. What innervates extensor pollicus brevis?
  52. What innervates extensor pollicus longus?
  53. What innervates extensor digitorum?
  54. What innervates extensor carpi ulnaris?
  55. What innervates flexor carpi ulnaris?
  56. What innervates flexor digitorum superficialis?
  57. What innervates palmaris longus?
  58. What innervates flexor carpi radialis?
  59. What innervates flexor pollicus longus?
  60. What innervates pronator quadratus?
  61. What innervates pronator teres?
  62. What innervates supinator?
  63. What innervates abductor pollicus brevis?
  64. What innervates flexor pollicus brevis?
  65. What innervates the opponens pollicus?
  66. What innervates the adductor pollicus?
  67. What innervates the abductor digiti minimi?
  68. What innervates the flexor digiti minimi brevis?
  69. What innervates the opponens digiti minimi?
  70. What innervates the lumbricales?
    • Median (1,2)
    • Ulnar (3-4)
  71. What innervates the dorsal interossei?
  72. What innervates the palmar interossei?
Card Set
Brachial Plexus
Based off of the slides in BYUI Bio460.