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Current time:0:00Total duration:4:22

Video transcript

all right so it's really important to keep your blood pressure under control if it's not under control and you let it get too high this extra pressure that's not supposed to be there it starts to damage the whole plumbing system higher pressures can both damage the pump which is your heart and the pipes which are like your arteries in your veins and if these two supply systems become damaged that organs they supply can also be damaged which is not good so let's think about this you've got this arterial pressure coming out of the pump and then this venous pressure coming into the pump right well what happens on the arterial side well the heart pumps blood out since there's this pressure though the heart has to basically pump hard enough to generate its own opposing pressure that overcomes this arterial pressure in order to actually get this blood moving around our system so let's remember that the two factors that affect pressure in the blood vessels are flow which is related to the volume of blood circulating around the body and then the resistance which like makes it more difficult for blood to move around so increasing either flow or resistance also increases our pressure right well there's actually an equation that relates these three guys and that's the following so you have your pressure out which is the same as our arterial pressure minus the pressure in which is like our venous pressure and is usually way lower than the arterial pressure and that is equal to the flow times the resistance so let's map these guys out as we move from pressure out from the arteries to pressure in from the veins we're going to run into some resistances you have some resistance R from the arteries and then a lot more from the arterioles which are like these smaller branches of the arteries and remember when the pipes get smaller our resistance actually goes up right and then finally after those arterioles we get to the capillaries which are like the smallest tiny little pipes that give blood to your tissues after the capillaries that get bigger and then come back to your heart through your veins and so finally you get a little more resistance from your veins but not much so that's the resistance but let's not forget to also add this like flow of blood circulating around which is a certain of volume of blood moving per minute which is our flow so from the equation if you increase the flow you increase the pressure or if you increase the resistance is say your arteries get narrower you also increase the pressure so anything that increases our pressure on the arterial side is going to make our heart have to pump harder right since it has to like overcome this increased arterial pressure so if this pressure goes up what do we do well let's think about that what's one way we could pump harder through our plumbing system well we can try to invest in a bigger pump right well that's not too far off actually because what happens when your heart needs to pump harder is that it's muscles actually get bigger which is called hypertrophy and at first you might think hey that doesn't sound so bad it's like when I go to the gym and bulk up my biceps and it kind of is so much so that it changes shape just like your biceps but when your heart changes shape and hypertrophy x' it actually ends up pumping less effectively so it's a less efficient pump if we take a look at all the chambers of your heart you've got the right atrium up top right which lets blood down into the right ventricle and in the left atrium up top left which goes down into the left ventricle and it's this left ventricle that does the pumping out to the body so it's this guy that usually tries to bulk up and gain muscle to beat out that arterial pressure not only does this extra muscle cause the part to pump less effectively as you can sort of see there's also less room in the chamber to fill with blood so now there's even less blood being pumped out with each beat and so less blood is delivered to the body in the organs so as both the filling volume and the pumping ability decreases are bigger and bulkier pump isn't going to do as good of a job in giving our body blood right and once happens it can be considered this early manifestation of heart failure which as we've seen is a result of a higher arterial blood pressure