Final answer:
The best procedure for demonstrating the cephalic, basilic, and subclavian veins is venography. This method involves injecting contrast dye and taking X-rays to visualize the venous system, including the pathways and connections of these specific veins.
Step-by-step explanation:
The procedure that will best demonstrate the cephalic, basilic, and subclavian veins is venography, which is an imaging technique that provides a visual representation of the venous system after injecting a contrast dye. To visualize these veins, the dye is introduced, and X-rays are taken to trace the path of the veins. The cephalic vein starts in the antebrachium and drains into the axillary vein, being superficial along the biceps brachii muscle. The basilic vein is medial in the forearm and flows into the axillary vein, while the subclavian vein forms from the axillary vein as it passes through the body wall from the axillary region and drains into the brachiocephalic vein.
The median cubital vein, which connects the cephalic and basilic veins, is commonly used for venipuncture due to its superficial location in the antecubital region. The subclavian vein receives blood from the axillary vein, which itself is formed by the union of the cephalic vein with the subscapular vein.