medial root of median nerve medial root of median nerve the medial root of median nerve is one of the two sources of the median nerve, the other being the lateral root of median nerve. medial root of median nervebrachial plexusthe right brachial plexus (infraclavicular portion) in the axillary fossa; viewed from below and in front.detailsidentifierslatinradix medialis nervi medianita98a14.2.03.032ta26458fma65243anatomical terms of neuroanatomy