Blood Pressure

by Jason Amores Sumpter
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Hello, everyone. In this lesson, we're going to be talking about blood pressure and how blood pressure is going to change. Depending on the different veins, arteries and capillaries. The blood is actually in. Okay, So first off, let's talk about the two different types of blood pressure. So I'm sure you've had your blood pressure taken by your doctor. And your doctor gives you these numbers. Generally, there are around 120 over 80 and that actually is your blood pressure. But it's actually two different versions of blood pressure. Thes systolic. Blood pressure is the top part of the fraction, and the diastolic blood pressure is the bottom part of the fraction. So what's the difference between these two? Because if you are a pre med student, you're definitely going to have to know these two different types of blood pressure. Okay, so the first one, the highest number, is going to be your systolic blood pressure. And this is the highest blood pressure that your arteries should actually experience and that your heart should actually experience and systolic blood pressure is going to be taken at the time. In the heart phase is called Sistol insist all is going to be the peak of contractions. So this is the peak of blood pumping out of the ventricles. So whenever the ventricles actively contract and push that blood out of the ventricles, that blood's gonna be of extremely high pressure because those muscles are actively squeezing on it. So systolic blood pressure is the highest blood pressure because this is going to be the pressure off the blood when the ventricles are actively contracting during the phase called Sistol. So Sistol is going to have a range of healthy blood pressures. And during the contraction phase or systolic phase thehuffingtonpost blood pressure should be so. The optimal blood pressure should be less than 120 millimeters of mercury, which is going to be a measurement of pressure. So anything less than 120 millimeters of mercury is good. So around that range is a good systolic blood pressure. Anything above 1 40 I believe, is going to be problematic and is going to cause high blood pressure, which is not good for your body. Okay, so now the second form off blood pressure is the diastolic blood pressure. This is going to be the one on the bottom of the fraction when you're given your blood pressure and this is the lower blood pressure that you experience. And it's the lower blood pressure because it's actually right before the ventricles contract and pump out blood. And this is because this is going to be the blood pressure of the DIA stall phase in the heart contraction phase. And this is actually the relax ation phase. And this is actually when the chambers of the heart are refilling with blood right before the contraction phase right before Sistol. So this is going to be the very low blood pressure of the heart and of the blood, because this is when the heart is relaxing and when the heart is actually refilling with blood so it can do another cycle of contractions. And this blood pressure also has an optimal blood pressure. And this is anything under 80 millimeters of mercury. Anything above that is considered high blood pressure and can be dangerous. So that's why they say that you want your blood pressure to be around 120 over 80. So let me draw this out for you guys, so your fraction would look like this. 120 over 80 millimeters of mercury. And this one right here is the systolic. And this one right here is the diastolic. So that's why you get two numbers whenever you get your blood pressure reading. Okay. All right. So now we use blood pressure to understand how the heart is functioning and how the blood is moving through the body. We also utilize pulse and pulse is actually going to be measuring the bulging oven artery during the heartbeat. So whenever your heart is beating, your arteries actually will bulge because the pressure and the force of the blood is increasing. So you guys can generally put your hands up next to your neck and find an artery, and then it will be pulsing. And that is because with every beat in contraction of your heart, more blood is being pushed through that artery. So it is going to expand. Okay, so the pulse is going to tell you about the heartbeat. How quickly are those contractions happening? And the blood pressure is going to tell you the pressure of the blood and how much force is being put on that blood. Okay, so now let's talk about high blood pressure because Americans do have an issue with this, and this is also called hypertension. And hypertension is long term, high blood pressure. This is anything over 120 especially over 140 for systolic blood pressure. Anything over that for a very long period of time is called hypertension. Hypertension is generally seen in Americans because we have a very high salt diet. But hypertension can be caused by, ah, high salt diet. Ah, high fat diet and a lack of exercise and hypertension can lead to a lot of issues. You can imagine if you have a lot of pressure on your heart and on your arteries in your veins at all the time throughout your entire life. You're going to have some issues from that, and this can cause coronary artery disease. This can cause a stroke. This can cause kidney disease and can cause a whole bunch of issues. So hypertension is generally bad, and this is generally medicated for or the diet has changed. But I want you guys to know that this is generally caused by diet, but it can also be caused by genetics as well. Some people have a higher propensity toe have hypertension than others. Okay. All right. So now let's look at this really neat graph which is going to be showing us The pressure's off these different areas of your cardiovascular system. So what we have is we have the pressures of these different vessels. So you have the aortic pressure, which is going to be the pressure of your aorta, which is the largest vessel in your body. And the left ventricle is going thio push blood into the aorta and we're going to have the pressure inside of the Atria is, and we're gonna have the pressure inside of the ventricles. Now, just do you guys know whenever you're measuring blood pressure, you're generally measuring the pressure of the aorta, the major arteries of the body. So whenever you're looking at these pressures on this chart, the one we generally go by to measure pressure of the blood is this one in red right here. The aortic pressure is generally what we utilize. And if you guys can see the way we know that is true is because we have the 120 we have the 80. That's the general healthy blood pressure for an individual. And that's how you know this is the one that we're measuring. We're measuring the aortic pressure. Okay. All right. So you guys know that we're measuring the aortic pressure, and I would like to show you the different phases off the hearts contraction. So the phase that is happening right here is Sistol. So this is the contraction phase. All of this right here is the contraction phase. And you guys can see that during the contraction phase, the aortic pressure is going to go from 80 all the way up to 120. That's gonna be the highest pressure when those ventricles air actively contracting and pushing the blood out. And then once this doll is ending, that pressure is going to go back down right around 2. 80. And that's because that is the filling stage. So this is going to be diastolic, and this is going to be diastolic as well. This is when the heart is actively refilling with blood. So the pressure here is much lower and you guys can see that the Atria and the ventricles also do change in pressure. You can see the ventricle pressure in black changes substantially. You guys can see that it's way down here. And then during Sistol, it just jumps up to these huge pressures. And that's because the blood inside off the ventricle is being actively squeezed and being given a ton of pressure. And it's just shooting that blood out of the ventricles. And then it's going to dramatically dropped back down during Dia stall, and the drop in blood pressure actually aids the heart and pulling more blood into it. So this is basically showing you the different pressures that the different areas of the heart and the different vessels experience. So the order is in red, and that is what we generally utilize for blood pressure. That's what we used to read. Blood pressure is the aortic pressure, but then we also have the ventricular pressure in black, and we have the atrial pressure in blue, and they're all going to vary. But the one that's most dramatic is the ventricular pressure, because it greatly jumps up during Sistol. Okay, guys. All right, so now let's go down and let's talk about how the blood vessels air going to deal with this gigantic change in pressure because the arteries are the vessels leading away from the heart and they're going to experience the most intense blood pressure, especially the aorta, which is going to experience the most intense blood pressure because that left ventricle is actively pushing blood into it. So the way they're going to combat this is that arteries have muscle fibers and elastic fibers. Help them deal with the high pressure. So this is going to be these muscle fibers, and these fibers that help it stretch and help it go back to its normal size during the different contractions of the heart. And the aorta is especially dense with these elastic fibers because it goes through this immense systolic blood pressure. This immense change in pressure every time those ventricles contract. Those fibers are there to help that to help make sure that these arteries don't burst. They need to be able to withstand this giant change in pressure. So now the arteries are going to have the highest blood pressure. The arteries air the vessels leaving away from the heart, and the arteries are the vessels that are actively being pushed blood into So they have the highest blood pressure. The veins and the cap pillories are gonna have the lowest blood pressure. Remember the cap Pillories are where nutrients and gas exchange are going to occur with the tissues of the body. And these are the smallest blood vessels, and then the veins are going to lead the blood back to the heart. So blood obviously is going to slow as it moves farther and farther away from the heart. And as it moves through the capital Aries, it is going to slow. And this is going to cause a substantial drop in velocity and pressure of the blood. But don't worry. Our bodies have ways to deal with that. So veins were going to have the lowest blood pressure and they're going to have these valves inside of them which arteries do not have. And these valves air going to ensure that even though this blood doesn't have a lot of speed and it doesn't have a lot of pressure, these valves air going to close to ensure that blood doesn't go back the wrong way, that it continues on its route to the heart and something really cool is veins in your extremities, like your legs and your arms and your hands are going to move through skeletal muscle. And then why do you think they move through skeletal muscle, where they're gonna move through skeletal muscle? Because every time you move your arms and your legs or any of your muscles, it's going to help create pressure to move the blood through the veins. So even though the veins don't have a lot of pressure from the heart, they are going to receive pressure from you moving your body, which is going to help blood move back to the heart. So it's really good to get up and walk around every once in a while when you're sitting at your computer or something like that to help your blood keep moving. Okay, all right, so now let's talk about the capillary specifically, so I have a diagram of a cap Hillary system right here and Cap Hillary's are going to deliver so many different things to our body tissues. So Cap Hillary's are important for delivering oxygen and taking away carbon dioxide. They're important for delivering water and delivering nutrients. They also take away wastes like uric acid and lactic acid that build up in ourselves. And they're basically the exchange system between the blood and the cells and guys, the the fluid that surrounds these cells that actively interacts with the cap. Hillary's is gonna be the interstitial fluid, and this is the fluid that leaks from the capital Aries and surrounds the cells. This is fluid in the blood, but it's not actively red blood cells. So this is where all of the nutrients and all of the gas is air going to be dissolved. And whenever the fluid leaves the cap, Hillary's it's going to do exchange with the cells. Now, whenever we're talking about pressure, we're going to have the arterials, which are the arteries that lead to the capital Aries, and we're gonna have the venue ALS. And the pressure in the arterials is relatively low. But in comparison to the venue ALS, it's high. So there's high blood pressure over here, and there's going to be low blood pressure over here, so this poses an issue. How does the blood actively go through this system? Because what's going to happen is blood is going to enter the arterials, and then it's going to enter the cap Ilary. And then, ah, lot of the fluid is going to leave the blood into the interstitial space. So how does the blood get that fluid back if the pressure is very, very low. So the pressure has dropped dramatically because a lot of the fluid has left the blood. So the pressure pushes the fluid out of the blood into the capital Aries into the interstitial fluid. Now, how does the blood get that fluid back? Well, the way it's going to get that fluid back is now the solute concentration in the venue. ALS is going to be incredibly high because all of the fluid left the blood. It left all the salts behind. But because all of the fluid left the blood and that left all the salts behind that osmotic pressure is going to be very high in the venue. ALS and the fluid is going to want to return to the blood to decrease the solute concentration. So, through osmosis, the fluid will return back to the venue ALS because the salt concentration is very high in the venue als So in the arterials, the fluid leaves the blood because it has high blood pressure. Now how does it get back into the venue? ALS Because of high osmotic pressure, Because the water is actively going to go back into the blood because of osmosis to counter act that very high solute concentration that is found in the venue ALS. So even though it sounds like a really complex process, it's not particularly complex. Basically, what you guys need to know is that the heart is going to push blood into the arteries and they're going to experience extremely high blood pressure. And then the arteries are going to lead to the capital Aries, where the exchange of nutrients and gasses and waste is going to occur. And the high blood pressure is going to push the fluids with all those dissolved nutrients and gasses out of the blood system into the interstitial fluid. But how does the interstitial fluid get back? It is going to get back via osmotic pressure, and it is going to re enter into the venue ALS because of osmosis and then the venue ALS are going to lead to the veins, which we're going to use their valves and their skeletal muscle to push the blood back into the heart so that the whole process can start all over again. Okay, everyone, let's go on to our next topic.