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Current time:0:00Total duration:6:21

Video transcript

so recently I went into my doctor's office and I was told that my blood pressure was 115 over 75 so I thought we would talk about exactly what this means and try to figure out how to add a think about blood pressure in general using these numbers in this experience as kind of a launching point so the way I think about blood pressure is I always imagined kind of a tube and I imagined blood going through that tube and this tube is like a blood vessel so there's blood trying to get its way from one side to the other and on its way the the kind of neat thing that it's doing is as it flows it's pushing out so it's forcing against these walls and it specifically what I mean by that in their cells and there's plasma and all that stuff is pushing out against the walls of the blood vessel so you've got a force and that force is being exerted on the surface area of the blood vessel so it's force over a surface area and anytime you see force over an area you know that equals pressure and in this case it's a blood pressure because it's the blood that's doing that work so this is how I think a blood pressure specifically is those little blue arrows and the two questions I kind of pop into my mind anytime I'm thinking about blood pressure are where is the blood pressure being taken and when are you taking it so let's start with the first question where and by that I mean where in the circulatory system so you've got the heart and it's my Valentine's Day heart and you've got the aorta coming off of the heart and it's got lots of branches but I'm going to just draw one branch which is the artery leading off to my arms this is called the brachial artery going off to my arm and usually I'd say 90% of the time maybe even more the blood pressure that you're getting recorded or the number that's being told to you is being checked at this point I marked it with a little X because that's kind of the upper arm right so that's usually where they're checking the blood pressure and again they're checking the force that the blood is putting on the vessel wall so these little blue arrows so that answer is the where question and certainly you can imagine if I check blood pressure let's say at some other spot you know let's say over here or over here you know you might get a different blood pressure reading then if I check out the yellow X so really we're just talking about that one spot now the other question is you know when are you checking it so for this let me show you a little table or a figure rather so imagine that over time time is this way you have different recordings for blood pressure so this will be blood pressure and blood pressure is usually measured in millimeters of mercury so I'll write millimeters of mercury here and let's go from 200 all the way down to zero and I'll use my numbers that I got from the doctor the other day to illustrate what I'm trying to say so right at that X that yellow X at the bottom let's say of my reading I've got 75 so let's start at 75 which is about here as the hardest pumping the pressure starts building up and it gets up to about 115 so really what is happening is blood is making its way from the heart as it squeezes towards that X and as it gets there the force that it's putting on the walls is going up up up and as it goes up it it goes from 75 all the way to 115 so that all happens during the squeezing part of the heart cycle and we call that systole so this is all happening during systole which is when the heart is squeezing down and we know the heart is a pump now from that point forward the heart begins to relax so at this point at 115 the heart is now relaxing slowly and as it relaxes the pressure begins to fall and it continues to fall all the way here and the pressure gets down to about 75 again and this is diastole so this is when the heart is actually taking a break from squeezing and is now refilling and we call that Vaseline so I'll call that refilling and so during systole you spend about 1/3 of the time and audacity spend about 2/3 of the time and I'm talking about one heartbeat here so this would be one heartbeat so it's not 50/50 and the easy way to remember this is in a given day 24 hour day I spend about 8 hours working at about 16 hours relaxing or or not working and so I think of the heart doing its squeezing its work for 8 out of 24 would be about a third kind of the same as me about a third of the time the heart is relaxing or other sorry squeezing so that's how the heart is spending its time in systole and diastole and the pressure is ranging between 115 and 75 so really it's never just 115 or just 75 it's somewhere between the two and you know for example if I checked right here in time you know it might be let's say 85 or here it might be 102 or here it might be you know it's 87 so it's somewhere between 15 and 115 and 75 so this number then this number I wrote up here becomes a range this is the range of blood pressure so when I talk about when it really depends on when in the cycle you're at and you're somewhere in that range and when I talk about the where we know that we're talking about a reading that's taken in the upper arm so those are the two thoughts that should cross your mind every time you hear a blood pressure recording and of course the top number 115 again is the systolic blood pressure and 75 is the diastolic blood pressure