Final answer:
When needling PC-3 (quze), avoid the brachial artery and veins to prevent bleeding, and also steer clear of the brachial plexus to avoid nerve damage.
Step-by-step explanation:
When needling PC-3 (quze), which is a point on the Pericardium meridian in Traditional Chinese Medicine (TCM) located on the elbow, care should be taken to avoid the brachial artery and veins. This is because the brachial artery is a major blood vessel which, if punctured, can lead to significant bleeding and subsequent complications. Needling deep can also lead to contact with the brachial plexus, which is a network of nerves that, if damaged, may cause numbness, weakness, or pain in the arm and hand.