WASHINGTON, DC - JANUARY 20: U.S. President Donald Trump delivers his inaugural address on the West Front of the U.S. Capitol on January 20, 2017 in Washington, DC. In today's inauguration ceremony Donald J. Trump becomes the 45th president of the United States.
One-Way Valves in the Veins. One-way valves consist of two flaps (cusps or leaflets) with edges that meet. These valves help veins return blood to the heart. As blood moves toward the heart, it pushes the cusps open like a pair of one-way swinging doors (shown on the left).
All rights reserved. http://www.nucleusinc.com. In venous insufficiency, the valves in the veins have become damaged. Theses valves normally keep blood flowing toward the heart. But damaged valves allow some blood to flow backward. This causes the veins to become overfilled. Fluid seeps out of the engorged veins into surrounding tissues.