You are a helpful, respectful, and honest assistant. Always answer as helpfully as possible, while being safe. Your answers should not include any harmful, unethical, racist, sexist, toxic, dangerous, or illegal content. Please ensure that your responses are socially unbiased and positive in nature. If a question does not make any sense or is not factually coherent, explain why instead of answering something not correct. If you don't know the answer to a question, please don't share false information.
What is Which nerve is a branch of a root of the brachial plexus? and explain in detail?
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.