Final answer:
Intravenous needles should be inserted bevel up to minimize vein damage and ease entry.
Step-by-step explanation:
When introducing a needle intravenously, the needle should always be directed bevel up. This orientation is chosen to minimize the risk of damaging the vein walls and to facilitate a smoother entry of the needle into the vein. Inserting the needle with the bevel up creates a small flap that eases the entry, potentially reducing pain and preventing complications such as phlebitis.