Brachial Plexus: Odds and Sods

1. Brachial Plexus: Odds and Sods Emily Matthews (e.k.matthews@warwick.ac.uk) Alex Clarke (alexander.clarke@warwick.ac.uk)

2. Content • Mnemonic for nerve roots of main nerves • Activity: Root values associated with key movements • Question: Axillary nerve

3. Nerve roots of main nerves THREE musketeers assassinate 5 rats, 5 mice, 2 unicorns LABEL YOUR FINGERS http://www.stritch.luc.edu/lumen/meded/grossanatomy/2013_2014/revisedbp14/revisedbp14_print.html

4. Nerve roots of main nerves THREE musketeers assassinated 5 rats, 5 mice, 2 unicorns

5. Nerve roots of main nerves THREE musketeers assassinated 5 rats, 5 mice, 2 unicorns

6. Nerve roots of main nerves THREE musketeers assassinated 5 rats, 5 mice, 2 unicorns FIVE MICE - Median FIVE RATS-

7. Nerve roots of main nerves THREE musketeers assassinated 5 rats, 5 mice, 2 unicorns

8. Root values associated with key movements Question 1

9. Root values associated with key movements Question 2

10. Root values associated with key movements Answer 1

11. Root values associated with key movements Answer 2

12. Root values associated with key movements MAIN POINT: Note how NOT all nerve roots of a named nerve are involved in movement e.g. Biceps brachii and brachialis muscles are involved in elbow flexion. These muscles are in anterior compartment of the arm and innervated by musculocutaneous nerve. Nerve roots of musculocutaneous nerve: C5, C6, C7 Brachioradialis also involved in elbow flexion. Innervated by radial nerve. Radial nerve has nerve roots C5, 6, 7, 8 & T1 However, only neurons from C5, C6 innervate muscles involved in elbow flexion, so the nerve root value of elbow flexion is C5, C6

13. Root values associated with key movements UPPER LIMB: From this year’s lectures slides: LOWER LIMB: From last year’s lectures slides

14. Question Bertha Jugs is diagnosed with breast cancer. Her surgeon performs a wide local excision and sentinel node biopsy. What is a sentinel node and what is the purpose of biopsying it? A sentinel node is the first lymph node a carcinoma drains to Sentinal node bx: radioactive (technetium 99) substance blue dye is injected into the nipple. Drains through the lymphatic system of the breast All blue/radioactive lymph nodes are excised (radioactive nodes detected with Gieger counter) If sentinel node clear of cancer then no need for further axillary node clearance. Useful as only affected lymph nodes are removed, thus reducing need for axillary node clearance in most women which is associated with pain and lymphoedema http://health.kernan.org/patiented/articles/sentinel_node_biopsy_000378.htm

15. Question An axillary node clearance is required for Bertha. (b) Name 5 main groups of axillary lymph nodes Central Humeral Apical Pectoral Subscapular CHAPS like breasts

16. Question The surgeon’s credentials are questionable. He blunders about in the axilla and damages the axillary nerve. (b) Describe the likely consequences of damaging the axillary nerve MOTOR SENSORY REFLEX • Deltoid and teres minor affected: • Loss of shoulder contour id wasting) • Weakness of shoulder movement except adduction • Limb hang limp at side • loss of sensation over regimental badge region • n/a