Final answer:
A larger gauge number for a needle indicates a smaller lumen. As the gauge number increases, the diameter of the needle's opening decreases, making the needle finer and thinner.
Step-by-step explanation:
A larger number gauge for a needle indicates a smaller lumen. The gauge of a needle refers to the diameter of its lumen, which is the hollow opening within the needle. In medicine, needles are typically sized by gauge numbers; the larger the gauge number, the finer the needle, which actually means it has a smaller lumen. So contrary to what might initially be assumed, a larger gauge number does not mean a larger needle. Instead, it means the needle has a finer, thinner wall with a smaller internal opening.