The present invention includes syringes with valves. The valves control communication between the interior of a barrel of the syringe and the exterior of the barrel. In syringes that include two valves, the valves may be oriented opposite one another, such that one of the valves may enable fluid to flow into the interior of the barrel of the syringe while preventing fluid from flowing in the opposition direction, while the other valve may enable fluid to flow out of the interior of the barrel while preventing fluid from flowing tin the opposite direction. Alternatively, a syringe may include a single valve, which is carried at or near a distal end of its plunger. Methods for using such syringes including, but not limited to manual pulsed aspiration methods and manual pulsed delivery methods, are also disclosed.
