Deltoid nerve innervation?

Deltoid nerve innervation?

• A. Radial nerve
• B. Median nerve
• C. Axillary nerve
• D. Musculocutaneous nerve

Answer: (C)

The deltoid is innervated by the axillary nerve, which arises from the posterior cord of the brachial plexus (C5–C6). The axillary nerve travels through the quadrangular space with the posterior circumflex humeral artery to reach the deltoid (and teres minor), providing motor fibers to all parts of the muscle. This enables arm abduction beyond the initial 15 degrees initiated by the supraspinatus. The nerve also carries sensory fibers to the skin over the superolateral aspect of the arm. The radial, median, and musculocutaneous nerves do not supply the deltoid, so the axillary nerve is the correct innervation.

The deltoid is innervated by the axillary nerve, which arises from the posterior cord of the brachial plexus (C5–C6). The axillary nerve travels through the quadrangular space with the posterior circumflex humeral artery to reach the deltoid (and teres minor), providing motor fibers to all parts of the muscle. This enables arm abduction beyond the initial 15 degrees initiated by the supraspinatus. The nerve also carries sensory fibers to the skin over the superolateral aspect of the arm. The radial, median, and musculocutaneous nerves do not supply the deltoid, so the axillary nerve is the correct innervation.