The trunks cross the base of the posterior triangle (see Fig. 8.186). Several branches of the brachial plexus may be visible in the posterior triangle (see Fig. 7.54 on pg. 730). These include the: dorsal scapular nerve to the rhomboid muscles, long thoracic nerve to the serratus anterior muscle, nerve to the subclavius muscle, and suprascapular nerve to the supraspinatus and infraspinatus muscles.