As previously noted, the median nerve arises from the medial and lateral cords of the brachial plexus.  A discussion of the brachial plexus is beyond the scope of this course.  It is important to note the relationship to the brachial plexus, as patients can have symptoms mimicking median neuropathy due to cervical or brachial plexus pathologies.

Within the arm, the median nerve travels inferior to the teres major muscle from the axilla.  The nerve then travels lateral to the brachial artery and vein.  This is an important anatomical feature to note, as the nerve at this location is susceptible to injury during PICC placement or midline placement, or even arterial access for endovascular treatments. Although rare, iatrogenic injury and trauma is the most common cause of injury at that level of the arm.