II. Anatomy: Brachial Plexus Divisions (at least 38 defined variations)

  1. Mnemonic ("Rip Taylor Drinks Cold Beer" or "Coffee Black")
  2. Spinal levels (C5 to T1) transition into 5 Roots (Rami)
  3. Roots (Rami) divide into 3 trunks
  4. Trunks divide into 6 divisions
  5. Divisions combine into 3 cords
  6. Cords divide into 5-6 brances

III. Anatomy: Images

  1. brachialPlexus.jpg
  2. entNeuroBrachialPlexusGrayBB808.gif Lewis (1918) Gray's Anatomy 20th ed (in public domain at Yahoo or BartleBy)
  3. orthoArmNeuroBrachialPlexusGrayBB807.gif Lewis (1918) Gray's Anatomy 20th ed (in public domain at Yahoo or BartleBy)
  4. orthoArmNeuroBrachialPlexusGrayBB809.gif Lewis (1918) Gray's Anatomy 20th ed (in public domain at Yahoo or BartleBy)

IV. Anatomy: Plexus Divisions

  1. Upper Plexus
    1. Shoulder abductors
    2. External rotators
    3. Elbow flexors
    4. Sensation to Shoulder and radial arm
  2. Lower Plexus
    1. Forearm and Hand motor function
    2. Sensation to ulnar arm, Forearm, and hand
  3. First Thoracic Ganglion (T1)
    1. Sympathetic face fibers
    2. Horner's Syndrome
      1. Ptosis
      2. Miosis
      3. Perceived enophthalmos
      4. Anhidrosis

V. Anatomy: Cords

  1. Posterior Cord
    1. Supplies Radial Nerve
  2. Medial Cord
    1. Supplies 1/2 Median Nerve
    2. Supplies all of Ulnar Nerve
  3. Lateral Cord
    1. Supplies 1/2 Median Nerve
    2. Supplies Musculocutaneous

VI. Anatomy: Plexus course

  1. Passes between middle and anterior scalene Muscles
  2. Passes beneath clavicle, joined by Subclavian vein
  3. Passes beneath pectoralis minor (in axilla)
  4. Lower Trunk (C8,T1) passes over first rib
    1. Associated with Thoracic Outlet Syndrome

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