Brachial Plexus: Odds and Sods Emily Matthews Alex Clarke

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

Nerve roots of main nerves THREE musketeers assassinate 5 rats, 5 mice, 2 unicorns LABEL YOUR FINGERS

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

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

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

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

Root values associated with key movements Question 1 JointMovementRoot value Shoulder Elbow Forearm Digit Hip Knee

Root values associated with key movements Question 2 SideJointMovementRoot value RightShoulder Elbow Hip Knee LeftShoulder Elbow Hip Knee Foot

Root values associated with key movements Answer 1 JointMovementRoot value ShoulderAbductionC5 ElbowExtensionC6, 7 ForearmPronationC6 DigitFlexionC7-8 HipAbductionL4, L5 KneeExtensionL3, L4

Root values associated with key movements Answer 2 SideJointMovementRoot value RightShoulderFlexionC5 ElbowFlexionC5, 6 HipFlexionL1, 2, 3 KneeFlexionL5, S1 LeftShoulderExtensionC6, 7, 8 ElbowFlexionC5, 6 HipExtensionL5, S1 KneeExtensionL3, 4 FootPlantarflexionS1, S2

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

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

Question Bertha Jugs is diagnosed with breast cancer. Her surgeon performs a wide local excision and sentinel node biopsy. (a)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 el_node_biopsy_ htm

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

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 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 MOTOR SENSORY REFLEX