The gauge of the needle is determined by the diameter of its

The gauge of the needle is determined by the diameter of its

• A. Hub
• B. Shaft
• C. Lumen
• D. Point

Answer: (C)

The gauge of a needle is defined by the size of its bore, specifically the internal hollow passage through which fluid travels—the lumen. This inner diameter determines how easily fluid can flow: a smaller lumen (higher gauge) creates more resistance and slower flow, while a larger lumen (lower gauge) allows faster flow. The hub, shaft, and point are physical parts of the needle that affect fit, stability, and penetration, but they do not set the gauge. So the lumen diameter is what the gauge is based on.

The gauge of a needle is defined by the size of its bore, specifically the internal hollow passage through which fluid travels—the lumen. This inner diameter determines how easily fluid can flow: a smaller lumen (higher gauge) creates more resistance and slower flow, while a larger lumen (lower gauge) allows faster flow. The hub, shaft, and point are physical parts of the needle that affect fit, stability, and penetration, but they do not set the gauge. So the lumen diameter is what the gauge is based on.