Why does blood flow with high pressure and speed in the arteries and not in the veins?
The arteries are the large blood vessels that carry blood from the heart to all the organs and muscles of the body, to give them the energy and oxygen they need. The arteries manage the flow of blood by controlling the speed and direction it flows in.
Because the blood inside the arteries is being pushed round by the heart, the blood pushes against the insides of the artery walls. This pushing is your blood pressure. To cope with this pressure, the artery walls contain tiny muscles to hold them in shape and allow them to become wider or narrower.
Opening and closing different arteries affects your blood pressure. The more narrow your arteries are, the less space there is for your blood to flow in and the harder it pushes against the arteries’ walls.