Question

Blood is transported throughout the body through both arteries and veins, but a significant difference between the two is the presence of valves in veins. Some people develop chronic venous disease (CVD), which initially causes higher venous blood pressure and vein dilation, resulting in weakened vein valves. What do you predict would happen as the valve damage progresses?
A.Blood would leak backwards through the damaged valves due to gravity, causing lower leg swelling.
B. Veins would thicken and constrict, causing a restriction in blood flow, and leading to arterial leakage.
C.Veins would carry a both oxygenated and deoxygenated blood away from the legs, causing oxygen deficiency.
D.Blood flow would increase through the veins since the blood would not be impeded by valves.

Answer 1

I think the answer is A, blood would leak backwards through the damaged valves due to gravity, causing lower leg swelling. The main function of the valves in veins is to prevent back flow of blood. Blood in the arteries, after being pumped by the heart, are under much higher pressure than blood in veins so there is no need for arteries to prevent back flow. However, within the veins especially those of legs are valves for the above function, therefore damaged valves would cause some back flow of blood, causing swelling of the legs.