Which part of the IV set prevents backflow of fluid?

The roller clamp is an essential component of an IV set because it can be adjusted to control the flow rate of the intravenous fluid. When the clamp is closed, it effectively prevents the backflow of fluid through the IV line. This is crucial in ensuring that medication or fluid does not return back into the IV bag, which could lead to contamination or dosing inaccuracies.

The injection port, while important for adding medications to the IV line, does not have any features to prevent backflow. The drip chamber allows for the observation of fluid flow and air issues but also does not prevent fluid from flowing back into the bag. The connector serves to join different parts of the IV system, but it doesn't have a mechanism in place to stop fluid from flowing back either.

In summary, the roller clamp's design enables it to function effectively as a control mechanism, playing a crucial role in maintaining the integrity and proper flow of IV therapy.