Which root values of the brachial plexus are responsible for the biceps jerk reflex?
- A C5 and C6 ✓
- B C7 and C8
- C C6 and C7
- D C5 only
Correct answer: A. C5 and C6
Explanation
The biceps brachii is supplied by the musculocutaneous nerve arising from the lateral cord of the brachial plexus, with root values C5 and C6. Testing the biceps tendon reflex assesses the integrity of these root levels. An absent biceps jerk in conjunction with weak shoulder abduction and forearm flexion indicates a C5-C6 lesion, as seen in Erb-Duchenne palsy.
Reference: BD Chaurasia's Human Anatomy, 8th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.