How does blood pressure differ in arteries capillaries and veins?

The blood (B.P.) differs based on the amount of blood which flows through the body at a given instant of time.
The Comparison Index
B.P. of arteries > B.P. of veins > B.P. of capillaries.
B.P. of Arteries
Arteries have the highest B.P. because blood gushes from the heart to the artery under a very high pressure. In fact the B.P. is so high that their walls are highly thickened.
B.P. of Veins
Veins have low B.P. for they bring deoxygenated blood back to the heart. Their B.P. is so low that they need valves to force blood in one particular direction.
B.P. of Capillaries
Capillaries have negligible B.P. for they are responsible for diffusion.
WALLS OF ARTERIES, VEINS AND CAPILLARIES.https://www.youtube.com/watch?list=PLCC2DB523BA8BCB53&v=NJzJKvkWWDc