What attaches the needle to the syringe?

The hub is the correct answer because it is the part of the needle that fits securely onto the syringe. It serves as the connecting piece that allows for a tight seal between the syringe and the needle, ensuring that medication flows smoothly through the needle without leaks. The design of the hub typically accommodates various types of syringes, making it a critical component in sterile compounding and the administration of injections.

Understanding the other components, such as the bevel, shaft, and lumen, helps clarify their roles as well. The bevel refers to the angled tip of the needle that facilitates easier penetration into tissues, the shaft is the long, slender portion of the needle that carries the medication, and the lumen is the hollow channel through which the medication flows. Each of these elements contributes to the needle's function, but it is the hub that specifically connects the syringe and the needle, making it the focus for this question.