Which nerve is a branch of a root of the brachial plexus?: (A) Suprascapular nerve, (B) Dorsal scapular nerve, (C) Upper subscapular nerve, (D) Lateral pectoral nerve
Answer is B. The roots of the brachial plexus are the anterior rami of spinal nerves Cs-T1. These five roots form the three trunks of the plexus. Each trunk divides into an anterior and a posterior division. The divisions form the three cords of the brachial plexus. The dorsal scapular nerve is a branch of the C, root. The supra scapular nerve is a branch of the upper trunk. The upper subscapular nerve and the thoracodorsal (middle subscapular) nerve are branches of the posterior cord. The lateral pectoral nerve is a branch of the lateral cord.