Which nerve innervates the teres minor?

Which nerve innervates the teres minor?

• A. Suprascapular nerve
• B. Axillary nerve
• C. Upper subscapular nerve
• D. Lower subscapular nerve

Answer: (B)

The key idea is which nerve supplies the teres minor. The teres minor is innervated by the axillary nerve, which comes from the posterior cord of the brachial plexus (C5–C6). The axillary nerve travels through the quadrangular space with the posterior circumflex humeral artery and provides motor fibers to both the deltoid and the teres minor, as well as sensory fibers to the skin over the lateral shoulder. Other nerves in the options innervate different muscles: the suprascapular nerve goes to the supraspinatus and infraspinatus; the upper subscapular nerve goes to the subscapularis; the lower subscapular nerve goes to the subscapularis and teres major. Hence, the axillary nerve is the correct innervation for the teres minor.

The key idea is which nerve supplies the teres minor. The teres minor is innervated by the axillary nerve, which comes from the posterior cord of the brachial plexus (C5–C6). The axillary nerve travels through the quadrangular space with the posterior circumflex humeral artery and provides motor fibers to both the deltoid and the teres minor, as well as sensory fibers to the skin over the lateral shoulder.

Other nerves in the options innervate different muscles: the suprascapular nerve goes to the supraspinatus and infraspinatus; the upper subscapular nerve goes to the subscapularis; the lower subscapular nerve goes to the subscapularis and teres major. Hence, the axillary nerve is the correct innervation for the teres minor.