Posterior view of the superficial muscles of the back; trapezius muscle is reflected on the left.

Brachial artery (red) and median nerve (yellow) anomalies. In 307 limbs studied, both primitive brachial arteries persisted in 5% (left image), the posterior in 82% (middle image), and the anterior in 13% (right image).

Brachial plexus & nerves of upper limb