How is your blood pressure constantly changing when you presumably have a relatively fixed amount of blood in a fixed amount of vein?

Question

I get that your heart can pump harder and whatnot, but when it’s a fairly closed system pumping the same blood around how does that actually increase the pressure?

In: 12

Answer 1

It is like current in an electrical circuit. The volume of blood your heart pumps per minute equals the current ( Amps), your vessels, mostly small segments of arteries before the tissue can contract or relax. This is the resistance(Ohms). The higher the resistance of your vessels, the more pressure is needed to press the blood through for any given volume. The more blood your heart pumps, the higher is the pressure at a given resistance. Blood pressure equals Voltage. U=R x I.
The veins don’t play that much of a role in blood pressure, it’s a more indirect factor as the veins regulate how fast the blood is returned to the heart after passing the tissue. They’re more like a reservoir feeding the pumping heart with the blood needed. Most of your blood, about 80%, is stored in the veins.

Answer 2

It is like current in an electrical circuit. The volume of blood your heart pumps per minute equals the current ( Amps), your vessels, mostly small segments of arteries before the tissue can contract or relax. This is the resistance(Ohms). The higher the resistance of your vessels, the more pressure is needed to press the blood through for any given volume. The more blood your heart pumps, the higher is the pressure at a given resistance. Blood pressure equals Voltage. U=R x I.
The veins don’t play that much of a role in blood pressure, it’s a more indirect factor as the veins regulate how fast the blood is returned to the heart after passing the tissue. They’re more like a reservoir feeding the pumping heart with the blood needed. Most of your blood, about 80%, is stored in the veins.