What is the part of the syringe that holds the drug solution?

The part of the syringe that holds the drug solution is the barrel. The barrel is the cylindrical portion of the syringe that contains the medication; it is designed to be strong enough to withstand the pressure required during injection and is typically marked with measurements to help the user accurately draw and administer specific doses. This measurement feature is essential for precise dosing in medical and veterinary applications.

The plunger, while essential for pushing the drug solution out of the syringe, does not hold the solution itself; it creates the force necessary to expel the contents. The needle is the sharp component that pierces the skin and allows the medication to enter the body but does not retain the drug. The term "cylinder" may refer to the shape of the barrel, but in the context of syringe parts, "barrel" is the specific term that describes the chamber housing the drug solution.