Which nerve root pairs contribute to the axillary nerve?

Which nerve root pairs contribute to the axillary nerve?

• A. C4-C5
• B. C5-C6
• C. C6-C7
• D. C7-C8

Answer: (B)

The axillary nerve comes from the posterior cord of the brachial plexus, and its fibers are from the C5 and C6 nerve roots. That’s why the root pair C5-C6 is the correct answer. These fibers travel in the posterior cord to become the axillary nerve, which innervates the deltoid and teres minor and provides sensation over the lateral shoulder. The other root pairings don’t contribute axillary nerve fibers, so they aren’t correct for this nerve.

The axillary nerve comes from the posterior cord of the brachial plexus, and its fibers are from the C5 and C6 nerve roots. That’s why the root pair C5-C6 is the correct answer. These fibers travel in the posterior cord to become the axillary nerve, which innervates the deltoid and teres minor and provides sensation over the lateral shoulder. The other root pairings don’t contribute axillary nerve fibers, so they aren’t correct for this nerve.