Nerves of the Arm
• The radial nerve will be on the back (i.e., posterior) of the arm – hence it comes
off of the posterior cord.
o This is also a clue as to the fact that the radial nerve will branch off into
the dorsal digital nerves (dorsal being on the posterior (back) of the
• Find the “M” first. The lateral cord will go deep, under the biceps brachii and
follow down along the arm. The lateral cord will follow along the lateral side of
the humerus to the ulna – it can be found between the olecranon and the lateral
condyle of the humerus (i.e., your funny bone – which isn’t a bone at all, it is a
nerve ). The middle part of the “M” will form into the median nerve, which will
follow along the upper arm and lower arm (i.e., forearm) on the anterior side – Nerves of the Arm
hence it will branch off into the palmar nerves (i.e., your palms being on your
anterior or front side of the body in anatomical position).
• Be aware: The “M” will not always be neat! Sometimes the middle dip of the
“M” will be neat (as the picture o