Expansion
Lateral, Medial and Posterior cords named by their relation to the axillary artery
Mnemonic
“Randy Travis Drinks Cold Beer” for the five levels, proximal to distal:
- R - Roots
- T - Trunks
- D - Divisions
- C - Cords
- B - Branches
“My Aunt Raised My Uncle” for the five terminal branches, lateral to medial:
- M - Musculocutaneous
- A - Axillary
- R - Radial
- M - Median
- U - Ulnar
The cords are named for their position relative to the axillary artery, which is why the lateral cord is lateral and the medial cord medial, not because of any root value.
Expansion
The three cords are named by their position around the axillary artery:
- Lateral cord - lateral to the artery
- Medial cord - medial to the artery
- Posterior cord - behind the artery
This is why the medial cord gives the ulnar nerve, which then runs down the medial side of the arm.