does bloodpressure cycle 120/80 occur 72 times a minute according to heart functioncycle or maintain avg value

Question

does the blood variation between 120 and 80 during systole and diastole occur 72 times a minute corresponding to heart compression and expansion or does it maintain a average value over a period of tome...?

Answer 1

First of all it depends on WHERE you are measuring. The very small vessels usually maintain a more or less steady pressure, because the energy of the "wave" has been absorbed by the preceding bigger vessels. Big vessels like the aorta are subjected to much bigger pressure changes during the cycle (from 10 to 200, for example). The "120/80" number is a convention and it refers to the branchial artery ONLY.

This measurement is supposed to provide the maximum pressure (120) and the minimum pressure (80) that acts on that vessel during a single cycle. The duration of the pulse varies but as a general rule the true "average" pressure is closer to 80 than to 120.

I can't plot the curve right now but think of it like a reverse U for the big vessels.

Answer 2

The systolic pressure is the pressure in the arteries when the heart is in systole (the pressure that the heart works against)
The diastolic pressure is the pressure in the arteries when the heart is at rest (the pressure that feeds the veins/fills the heart)
The avg pressure (Mean arterial pressure) is not simply (120 + 80)/2. Because the heart spends more time in diastole than systole, MAP is calculated to correct for that (I'm blanking on the exact formula though)
I'm sure this isn't real clear, but hope it helps some at least

Answer 3

For 0.3 seconds it is 120 mm of mercury. Immediately after for 0.5 secs it is 80 mm of Hg.

Answer 4

Blood pressure in the arteries change according to the rhythm of the pulse rate. Please see the webpages for more details on Blood pressure.