Each of the three trunks of the brachial plexus divides into an anterior and a posterior division (Fig. 7.52):
The three anterior divisions form parts of the brachial plexus that ultimately give rise to peripheral nerves associated with the anterior compartments of the arm and forearm.
The three posterior divisions combine to form parts of the brachial plexus that give rise to nerves associated with the posterior compartments.
No peripheral nerves originate directly from the divisions of the brachial plexus.