Precise volumes of fluid must often enter or leave the body through a needle. A syringe is a simple pump consisting of a barrel and plunger, used with a needle or other fitting to inject or withdraw fluids.

Syringes deliver medications, vaccines, and local anesthetics, and aspirate blood or other fluids. Graduated markings allow accurate dosing. Single-use disposable syringes dominate modern practice to prevent cross-infection. Safety-engineered designs reduce needlestick injuries.

Correct technique includes asepsis, appropriate needle size, correct site, and safe disposal in sharps containers. Errors in volume or route can cause serious harm. Training and standardized procedures keep syringe use both effective and safe.

• Device for injecting or withdrawing measured fluid volumes
• Consists of barrel, plunger, and usually a needle
• Predominantly single-use to prevent infection
• Requires aseptic technique and safe disposal