Washington Esthetician State Board Practice Exam 2025 – Complete Prep Resource

The main responsibility of the radial nerve is indeed to supply the arm and the back of the hand. This nerve is a crucial component of the brachial plexus, providing sensation and motor control to the posterior aspect of the arm and forearm. Specifically, it enables movement and sensation in areas such as the triceps muscle and the extensor muscles of the wrist and fingers. By facilitating these functions, the radial nerve plays a pivotal role in allowing individuals to perform various tasks involving arm and hand movements.

The other options refer to different physiological functions that are not associated with the radial nerve. For instance, supplying blood to the heart relates to the cardiovascular system rather than the nervous system. Controlling movements of the wrists and fingers typically involves both the radial nerve and other nerves, but the radial nerve specifically focuses on the extension of these areas. Transmitting signals to the lower body pertains to different nerve pathways and branches that are part of the lumbar plexus, not the brachial plexus where the radial nerve is located. Thus, option D accurately reflects the primary responsibilities of the radial nerve.