Which muscle is innervated by the axillary nerve?

Which muscle is innervated by the axillary nerve?

• A. Latissimus dorsi
• B. Pectoralis major
• C. Deltoid
• D. Subscapularis

Answer: (C)

The axillary nerve primarily innervates the deltoid muscle, enabling shoulder abduction after the initial 15 degrees (with the first part of abduction driven by the supraspinatus). It also supplies the teres minor and provides sensation to the skin over the lateral shoulder. Other muscles listed have different nerve supplies: latissimus dorsi is innervated by the thoracodorsal nerve; pectoralis major by the lateral and medial pectoral nerves; and subscapularis by the upper and lower subscapular nerves.

The axillary nerve primarily innervates the deltoid muscle, enabling shoulder abduction after the initial 15 degrees (with the first part of abduction driven by the supraspinatus). It also supplies the teres minor and provides sensation to the skin over the lateral shoulder.

Other muscles listed have different nerve supplies: latissimus dorsi is innervated by the thoracodorsal nerve; pectoralis major by the lateral and medial pectoral nerves; and subscapularis by the upper and lower subscapular nerves.