The brachial plexus (BP) represents a complex network of nerves originating from spinal roots C5 to T1, with potential contributions from C4 or T2 in prefixed or postfixed variations, respectively. Its main function is the motor and sensory innervation of the upper limb. At the intervertebral foramen, motor and sensory roots unite to form spinal nerves, which contribute to the formation of the brachial plexus. It further organizes into roots, trunks (superior, middle, inferior), divisions (anterior, posterior), and cords (lateral, medial, posterior), to finally end into terminal branches. At each level, several motor and sensory nerves branch to innervate specific muscles.