College of Massage Therapists of Ontario (CMTO) Practice Test

Understanding the brachial plexus means recognizing its role in innervating the upper limb and which nerves arise from it. From the ventral rami of C5 through T1, the brachial plexus organizes into trunks, divisions, cords, and eventually five terminal branches: musculocutaneous, axillary, median, radial, and ulnar nerves. These are the nerves responsible for motor and sensory functions in the arm and forearm. The Sciatic and Tibial nerves originate from the lumbosacral region and supply the lower limb, not the upper limb. The Phrenic nerve arises from the cervical plexus (C3–C5) and controls the diaphragm, not a branch of the brachial plexus. So the statement listing the five specific nerves as part of the brachial plexus is the correct description.