The biceps tendon reflex involves which spinal nerve roots?

The biceps tendon reflex involves which spinal nerve roots?

• A. C5 to C6 nerve roots assessed via elbow flexion response.
• B. C7 to C8 nerve roots.
• C. C4 to C5 nerve roots.
• D. L2 to L4 nerve roots.

Answer: (A)

The biceps tendon reflex mainly tests the C5–C6 spinal nerve roots. When the biceps tendon is tapped, the sensory signal travels via the musculocutaneous nerve to the spinal cord at C5–C6, and the motor command returns through the same nerve to cause elbow flexion. That elbow flexion response indicates intact C5–C6 pathways, which is why this reflex is used to assess those specific nerve roots. The other options relate to different reflexes or regions: for example, the triceps reflex is more associated with C7–C8, while L2–L4 relate to knee-jerk testing, and C4–C5 would involve other upper-limb reflexes rather than the biceps.

The biceps tendon reflex mainly tests the C5–C6 spinal nerve roots. When the biceps tendon is tapped, the sensory signal travels via the musculocutaneous nerve to the spinal cord at C5–C6, and the motor command returns through the same nerve to cause elbow flexion. That elbow flexion response indicates intact C5–C6 pathways, which is why this reflex is used to assess those specific nerve roots. The other options relate to different reflexes or regions: for example, the triceps reflex is more associated with C7–C8, while L2–L4 relate to knee-jerk testing, and C4–C5 would involve other upper-limb reflexes rather than the biceps.