Summarize the divisions and cords of the brachial plexus, including their main branches.

Here is a summary of the information provided about the brachial plexus: Divisions*: Within the posterior triangle of the neck, each trunk of the brachial plexus divides into two branches: an anterior division and a posterior division. The anterior divisions generally supply flexor muscles, while the posterior divisions generally supply extensor muscles. These divisions then leave the posterior triangle and pass into the axilla region. Cords*: Once the anterior and posterior divisions have entered the axilla, they combine to form three main cords, named according to their relationship to the axillary artery: 1. The Lateral Cord: Formed by the anterior divisions of the upper and middle trunks. 2. The Posterior Cord: Formed by the posterior divisions of all three trunks (upper, middle, and lower). 3. The Medial Cord: Formed by the anterior division of the lower trunk. These cords then give rise to the major terminal branches of the brachial plexus: • Lateral Cord Branches: Lateral pectoral nerve Musculocutaneous nerve Lateral root of the median nerve • Posterior Cord Branches: Upper subscapular nerve Lower subscapular nerve Thoracodorsal nerve Axillary nerve Radial nerve • Medial Cord Branches: Medial pectoral nerve Medial cutaneous nerve of the arm Medial cutaneous nerve of the forearm Medial root of the median nerve Ulnar nerve 3 done, 2 left today. You're making progress.