human
How is a syringe used to take blood from a vein?
assistant
A syringe is typically used to draw blood from a vein. The needle of the syringe is inserted into the patient's vein, and then the plunger is pushed back and forth in order to create suction that draws blood up into the syringe. Once enough blood has been drawn, the needle is removed from the patient's vein, and the syringe is then capped off and sent to a laboratory for analysis.