ABSTRACT
A. The roots of the brachial plexus are C5-T1 and are found between the middle and posterior scalene muscles.
B. The three trunks are upper, middle, and lower and are found in the anterior triangle of the neck. C. The cords are named according to their position in relation to the axillary vein (lateral,
posterior, and anterior). D. The lateral cord contains contributions from C5, C6, and C7 and is the only cord forming the
musculocutaneous/myocutaneous nerve. E. The medial cord contains contributions from C7, C8, and T1 and is the only cord forming
the median nerve.
