The brachial plexus, wired
Five roots, three trunks, six divisions, three cords — and the nerves of the upper limb at the end. Each root sends its own colour down every path it takes, so you see what each nerve is made of. Cut anything and watch what the arm loses.
Click any nerve on the specimen, or its name beside it: a root, a trunk, a cord or a nerve. Its roots light up, its pulses stay on, and everything else fades.
Or start from one of these
Turn the network: the anterior divisions, the lateral and medial cords and their nerves are in front (flexors); the posterior divisions, the posterior cord, the axillary and radial nerves are behind (extensors).
A teaching schema, not measured anatomy: the plexus is drawn as the textbook pattern (root values after Moore, Clinically Oriented Anatomy), with front and back planes for the anterior and posterior divisions. Real plexuses vary — prefixed (C4) or postfixed (T2), a C5 share in the median, a C7 share in the ulnar. The % lost counts root levels, not axons.
Anatomy view: Z-Anatomy (CC BY-SA 4.0) — the nerve courses, bones and muscles of a real specimen, left side, seen from the front. Z-Anatomy's own wiring in the axilla is incomplete, so the divisions, the lateral and medial cords and the first centimetres of each branch are redrawn to the textbook pattern above, placed by the landmarks rather than measured.