If you're seeing this message, it means we're having trouble loading external resources on our website.

If you're behind a web filter, please make sure that the domains *.kastatic.org and *.kasandbox.org are unblocked.

Main content
Current time:0:00Total duration:7:09

Hypertension effects on the blood vessels

Video transcript

now we've talked about hypertension and you know that it means that you have high blood pressure so the next logical thing to think about is why is that bad why is it a problem to have high blood pressure and I like to think about high blood pressure from kind of two different perspectives one would be the perspective of the heart and the other is the perspective of the blood vessels and so here you can almost divide it up as the the thing that's making the pressure and or generating the pressure which is the heart and the thing that's receiving the pressure so generating versus receiving pressure and each of these two areas has some serious consequences for the body so let's let's divide it up here let's just draw kind of a dashed line divide up our screen and we'll talk about both areas so let's start with the receiving pressure side so we have the large and middle sized arteries and specifically I mean arteries that are between let's say 25 millimeters in diameter all the way down to about one millimeter in diameter so these are primarily these are the vessels that are going to get blood from the heart to the different organs that it needs to get to and then you of course have these small arteries the small arteries and the arterioles and these are going to be at the high end they're gonna be one millimeter but they're gonna go all the way down get smaller and smaller to about 0.01 millimeters so about a hundredth of the size they're very tiny and these are receiving pressure both of them they're receiving pressure these all draws I'll leave the drawing up above and these are kind of very very narrow ones right so both of them are receiving the pressure and they're gonna have problems so for example if you have let's say a larger middle artery that is let me draw in color let's see you know it's here it's very elastic all right elastic over time if you keep exposing this elastic vessel or tube to high pressures over time what would happen is this becomes very firm very firm like a like a pipe so that's one change and in fact that that change from being elastic to firm we call that arteriosclerosis I'll write that in white arterial sclerosis and in fact a very similar thing happens on the other side with the small arteries and arterioles they also can have very similar kind of change and they can go from being very elastic I'm trying to draw it so it's got some springiness so that's obviously I kind of tricky to draw but it becomes very firm these become very firm as well over time and they lose that elasticity and when it happens in the small arteries or arterioles we call that arteriosclerosis slightly different Acurio low an extra Ellen and OH sclerosis so this is the difference right the very similar things kind of similar processes but one is in the smaller arteries one is in the the larger middle sized arteries so this is one of the things that can happen when you have lots of high blood pressure constantly exposed to these vessels they can become firm okay going back to the larger middle of arteries you also can have a situation I'll draw it here where you have an artery let's say actually let me write what it is first you can have an aneurysm and an aneurysm is where you have a vessel let's say this is my vessel and it's it's taking blood through it the blood is going through it and because of the constant blood pressure that's going through this vessel the wall starts to get weak so at one spot it starts to get weak let's say right here instead of being like that it starts to look like this and you got this like little area of weakness I'll try to draw like that and because it's weak the blood will start going and hitting and bouncing off the walls and making it a little bit bigger so it looks like that and over time it might do this might become like a big sack and that's an aneurysm and actually that aneurysm if it's a sack of blood can actually burst and break and that blood can spill out and we call that hemorrhage so you can actually have an aneurysm because of a weak vessel wall and now looking at the small arteries or arterioles you can also have not necessarily an your's as aneurysms in the same way but you can have breaking or hemorrhage and and here I want to show you I'll remind you that these vessels these tiny ones anyway they're usually not sitting out there on their own they're usually within an organ so this tiny vessel remember it's one millimeter to a hundredth of a millimeter so it's actually sitting inside of a kidney or sitting inside of an eye and so these organs have inside of them these arterioles and small arteries and so when they're in that situation if you have a break let's say actually the media let me write this slightly differently if you have a break in the vessel you actually get organ damage so this could be because the the vessel literally breaks right here and blood spills out and it could also be because these tiny vessels are necessary to make the organ work for example the kidneys require that these small arteries and arterioles are working properly and if they're not you start getting some problems with being able to to do the job of the kidney and so you can get kidney damage or if it's in your eye you can get what we call retinopathy retinopathy basically meaning that the retina is not working properly retinopathy so you can have kidney damage a retinopathy you can have aneurysms arteriosclerosis or arteriolosclerosis and these are all related to the fact that the blood vessels are breaking or they're becoming more firm and this is on the side of receiving pressure