the contraction of muscles
Blood flow is faster in arteries than in veins. Blood flow in veins is lower pressure.
Capillaries do not have valves to regulate blood flow. Veins are the vessel of the circulatory system that have veins to regulate blood flow.
There are one-way valves (leaflet valves) in the veins which normally allow blood to flow only back to the heart. Muscle pressure is the main force pushing blood back from the extremities, especially against gravity in the legs. When the valves malfunction or are affected by high blood pressure, the vessels can form varicose (swollen) veins, blue veins, or spider veins.
The contraction of muscles and one-way valves in the veins help facilitate the flow of blood through the veins.
Gravity
Veins
Veins.
Veins
there are two main veins that makes the blood flow toward the heart which are the superior vena cava and inferior vena cava.
blood flows into the veins quiet slowly as they are much wider compared to the flow of blood in the arteries which are rather narrow.because of the low pressure of blood on the flow inside the veins there are great possibilities that the blood is likely to flow backwards which may cause complications in the flow of blood.to prevent this from happening the veins contain valves that stop the back flow of blood
The ventricles contract and force the blood under pressure, past the semi lunar valves into the arteries. The closing of the bicuspid and tricuspid valves prevents back flow. At the same time the atria and ventricles relax and blood begins to flow back into them from the veins.
Veins and artery's and Capillaries