Fig. 4. (  A ) A cross-sectional overview of the anatomy of the brachial plexus in the supraclavicular region (sagittal plane) from a 63-yr-old female cadaver with end-stage kidney disease (body mass index [BMI] 25.9 kg/cm²) (  B ) Histologic overview of the same plane. A = subclavian artery; V = subclavian vein; c = clavicula; S = skin surface; L = lung;  arrowheads indicate the epineurium, which refers to the outer border of the brachial plexus. * The most superior part of the brachial plexus. Note that identification of individual trunks is visually difficult.  Scale bar = 10 mm.