welcome back this is part two of our cardiovascular lecture and we're going to get into some cardiovascular variables here and what changes with exercise so a little bit of a review of some information and some variables some abbreviations on variables that we use in exercise physiology and then we'll see a lot of information about adaptations and how things change and how we Supply the demand to our tissue as we're exercising so when we talk about variables in exercise physiology these are very important to be familiar with so one of these is stroke volume so stroke volume is defined as how much blood is ejected out of my left ventricle per contraction so every time my left ventricle squeezes to eject blood out to my peripheral vascular system how much blood leaves the left ventricle which each one of those contractions so very important variable there now another variable that's important here is IND diastolic volume so IND diastolic volume volume is the volume within the chamber at the end of diast so be familiar with syy and diast so syy up here we'll write it Cy is the contraction of your ventricle and diast is the relaxation phase of the cardiac cycle so one cyia can contraction and then a relaxation a diast that's one cardiac cycle so we go through these phases of contraction and relaxation now how much blood fills the chamber before it contracts so how much blood empties from The Atrium Into The ventricle during that relaxation phase that's in diastolic volume and then in cystolic volume is exactly what the the variable is telling you there how much volume is left in the chamber at the end of syy at the end of the contraction phase we don't pump 100% of the volume of fluid out of the chamber with every contraction we'll talk about reasons why we do that later on but that gives us a little bit of a benefit to have some fluid left in the chamber at the end of syy so how do we get stroke volume we take our IND diastolic volume how much blood filled the chamber minus how much blood was left in the chamber at the end of the contraction and that tells us how much blood was pumped out with the contraction and that's what stroke volume is now another variable recognized as Q is known as cardiac output so this is the volume of fluid pumped by the left ventricle per minute so what we're doing here is we're taking our value of our stroke volume volume per contraction and multiplying that by how many times do we contract per minute in other words your heart rate so that gives us an estimation of how much blood is pumped by the left ventricle per minute in a practical sense this tells us how much blood is being sent out to the periphery to supply the tissue so cardiac output is a very important variable when we're talking about exercise because that's going to tell us are we supplying the demand that exercise is placed on the body usually we'll see cardiac output expressed in this unit of measure right here with liters per minute so that comes from stroke volume is expressed in liters and heart rate is expressed in beats per minute so we combine these two together and we get the liters per minute variable or unit of measure there says here cardiac output is normally around 5 lers per minute at a resting state where does this five come from can you go back to our first lecture on cardiovascular and think about why do we get the number five remember that males we'll write it here males generally have five to six liters of blood in the body and females generally have four to five lers of blood in the body so if we take the average of these two then we get five lers of blood on average in the human body and that's where the cardiac output of 5 lers per minute comes from at a resting state so what that means is every one one unit of blood makes a full circuit through your body from the left ventricle all the way returning back to the right ventricle in 60 seconds now how do we calculate everything this is just a a diagram a picture here showing you what in diastolic volume is so if we think of this right here is our left ventricle our chamber then how much blood is filling that chamber before it contracts so during that di diastolic phase uh the relaxation phase there and then end of ventricular contraction what we end up getting is as we empty that chamber out how much blood leaves the chamber is our stroke volume and how much blood is left in the chamber is our in systolic volume so you can see here we started with 100 milliliters that's how much blood filled the chamber prior to the contraction and then we contracted we got our Cy of the left ventricle and we see that we pumped out about 60 milliliters so that leaves us with 40 milliliters left in this uh ventricle after contraction here's the mathematical formula for all of that over here now let's skip down to picture C down here and what we end up doing is we'll take our stroke volume so our 60 MLS here that we saw from this picture right there multiply that by a heart rate of 80 beats per minute and that gives us a cardiac output of 4.8 L per minute or roughly almost 5 L per minute what we said on average from the previous slide at a resting state now let's jump back up to picture B right here and talk about something called EF so what that stands for is ejection fraction and this is a variable that's going to be expressed you can see over here as a percentage so ejection fraction comes from taking our stroke volume and the amount of blood pumped per contraction and dividing that by how much blood was in the chamber prior to the contraction so we see our 60 MLS of stroke volume divided by our 100 MLS of IND diastolic volume and that gives us an ejection fraction here of 60% in other words 60% of the blood that filled your chamber was ejected out with that contraction believe it or not this is actually a good value what we want to look for is something between 50 and 70% % that means that your left ventricle is pumping efficiently effectively and supplying the demand from all the metabolic standpoint within the body when we generally see this drop um below 40% that's what we can talk about later on is called heart failure it's an indication of heart failure meaning that your left ventricle is not pumping enough Blood Out to the systemic circuit to supply the demand but we don't want to see this value go up above 70% so we'll do this we don't want it to see above 70% that means that your left ventricle is actually too strong and it's pumping too much blood out of The ventricle we want a little bit of blood left in The ventricle for several reasons one it helps us to maintain pressure differences between the chambers between the vasculature and so on so that our heart can function appropriately we also don't want to empty that chamber out because think if this is my ventricle right here and I empty the chamber out as the atriums up here dump blood down into the ventricles if it's empty then that can create swirling of blood within your ventricle here which technically from a practical sense could create bubbles in your blood so we want to try and avoid different situations so by leaving some blood down here in the chamber if we just shade this in and that's our ejection fraction the uh the remaining blood within the ventricle when new blood comes in it mixes here and we don't get the swirling of the blood so when The ventricle contracts then it pumps that blood out through the aorta and into the systemic circuit so what are some factors that can increase the return of blood back to the heart remember about 60 say 60 65% of your total blood volume is located in your veins at a resting state so as you get up and you start moving and you place a demand on the body such as exercise we have to get more of that blood to come back to the right side of the heart so we can send it to the lungs and oxygenate it then back to the left side of the heart so we can send it out through our body to supply the metabolic demand within our tissue so the mechanisms to get all of that blood to rush back to the right side of the heart one we have breathing so as you get up and you start moving your respiratory rate is going to a change which changes the pressures within your thoracic cavity and squeezes on your veins and forces the blood to go back to the heart the way that we force blood to go back to the heart is oneway valves so we'll write that oneway valves which is what you see right here so connect that there that's our one-way valve and this is say coming from down here this is my foot and then I'm coming back up here to my heart where I have my right atrium and right ventricle left atrium left ventricle so what I'm doing is by muscle pumps so this is example of muscle pump as you contract the muscles the muscle squeeze in on the veins and it forces the blood along with your breathing changing your thoracic pressures the blood is forced to go up past pass this oneway valve as it passes through this one-way valve the valve closes back down so it allows you to prevent backf flow of blood going back towards your feet now every time your muscle contracts and the pressure changes again it forces the blood to go up through this valve and then as it passes through there the blood or the valve closes off again and it prevents that back flow as well so that we do that all the way until we get back to the right atrium and then we can get the blood to the right ventricle and send it over to the lungs so that we can oxygenate it this is something that's very interesting about the heart and what the heart does as we get this big influx of blood coming back to it so remember again 6 65% of the blood volume total blood volume is located in your veins now I'm going to get up and I'm going to start exercising so I've got this huge rush of blood coming back to my heart that's a lot of volume of fluid coming back to a little bitty organ so we have to be able to accommodate that the way that we accommodate that is something known as Frank Starling law or the Frank Starling mechanism of the heart what Frank Starling mechanism says is as you increase the enddiastolic volume you have more fluid coming back to the right side of the heart the heart has to accommodate for that so it's going to end up stretching remember our properties of your cardiac muscle tissue is very similar to your skeletal muscle muscle tissue so as you stretch that muscle tissue remember from unit two we said as you stretch you go into um compare this to the vertical jump I don't jump up and jump as high as I can standing here from an upright position with my knees locked out I go into that counter movement phase first before I jump up what that pre- stretch does is it stretches my muscle tissue it increases my crossbridge formation between my acting and mein and it also stores elastic energy that's why I have a more forceful uh production of force coming from my muscle tissue in that vertical jump with Frank Starling law what this says is as we've send more blood back to the heart we accommodate it by stretching well by stretching your cardiac tissue you end up storing elastic energy within there which in turn increases the strength of the contraction when it goes into the systolic phase so by doing that we increase something called contractility which is just a fancy word for saying the strength of the contraction that's good because we had so much more fluid coming back to the heart we need to increase the strength of the contraction so we can pump all that fluid out and maintain our ejection fraction around that 50 to 70% so Frank Starling mechanism is an incredible uh principle or an Incredible action of the heart that allows us to be able to accommodate all of this Blood rushing back to the heart and we can get it oxygenated and then send it out to the systemic circuit to supply the demand of our tissue so that gets us to something uh looking at how do we regulate our stroke volume so let's talk about this left side of the heart right here this is the left side this is the right side of the heart let's talk about the left side first the left side of the heart coming from the left ventricle right here has to overcome something called afterload so after load is created by the pressures out in your periphery in other words it's created by blood pressure so what happens is we send blood out through the aorta and out to your systemic circuit but even though the blood is traveling in that direction because of the pressure within our blood vessels there's a pressure being inerted back on the left side of the heart so that means the left ventricle has to create enough pressure when it contracts to overcome this back pressure to make sure that blood goes in this direction out to the periphery that's going to change so this back pressure is known as after load and that's going to change depending on factors like hypertension and Vaso constriction even vasod dilation when you go into exercise and other things things that are associated with your blood vessels but it's just important to remember that the left ventricle has a very hard job that's why the muscular wall of the left ventricle these areas right here are thicker than the right ventricle because they're stronger they have to be stronger to be able to overcome this back pressure being pushed back on your heart so we make sure that the blood goes out to the body now over here we have something called preload so preload is very similar to that indolic volume that we talked about earlier which it's the amount of blood that is loading the chamber prior to the contraction so if we look over here it says how does the body control this during exercise well think about what happens during exercise how do what do we do with all of the blood that's in the body we have to redistribute blood to all the active tissue skeletal muscle tissue while you're Contracting it needs oxygenated blood so what's going to happen to the blood vessels within the active tissue hopefully you remember the term Vaso constriction and vasod dilation in the active tissue the blood vessel is going to vasodilate it's going to get bigger because we need to accommodate more blood coming to the active tissue so uh what happens to after load during exercise is it's usually reduced or minimized here because of the dilation of the blood vessels within the active tissue so think about that let's get rid of these if this was my blood vessel right here coming down say to my lower body to my legs and then I go into exercise this is at a resting state this is a diameter of diameter of it right now now I go into exercise and I make that blood vessel bigger so I dilate it what that does is more of that blood can rush through the tunnel and get to my active tissue so there's less pressure being pushed back on my left ventricle so we see that that's one way that we can supply more blood to our active tissue is by dilating the blood vessel opening it up so it reduces the pressure within the blood vessel meaning there's left less pressure coming back on the left side of my heart there so what is blood pressure blood pressure is the pressure exerted on the blood vessel wall um as blood is flowing through there so if this is my blood vessel right here blood is going to be traveling through this blood vessel so I've got this chamber right here and blood's going to rush through the chamber uh all the way down to my active tissue so as blood is flowing through this Tunnel right here there's pressures being exerted because every time your left ventricle contracts it creates something called pulsatile flow so pulsatile flow what that means is you get these pulses these waves of blood coming through your blood vessel so my left ventricle contracts it sends a new wave of blood out now it contracts again a new wave and then a new wave that's the reason that if I come right here I come here here wherever it is I can feel that pulse uh over my arteries and and arterials is because that wave of blood is being pushed through the blood vessel that's pulsatile flow well every time a new pulse a new wave comes through there it creates this pressure inside your blood vessel that's what blood blood pressure is so when we see blood pressure written for instance if you see something like 120 over 80 what's considered a quote unquote normal blood pressure the top number here is your systolic blood pressure that's the pressure during the contraction phase of the C cycle it's always going to be a higher number than the bottom number right here which is known as your diastolic blood pressure so diastolic blood pressure is the pressure within the arteries and arterials during the relaxation phase of the heart so as your heart is filling back up with blood there's still an amount of pressure because of that after load coming back on your heart so it's going to be your lower value when we look at it on the formula on the bottom number that gets us to something called mean arterial pressure so mean arterial pressure is the average pressure in your blood vessels as the blood travels through your arteries and arterials the way that we can calculate this is take diastolic blood pressure plus you know 33 or roughly 13 of systolic minus diastolic that's a little bit more of the complic complicated formula instead we can use this formula right here where we're taking systolic blood pressure plus two times your diastolic blood pressure divided by three the reason that we do this is because in the cardiac cycle we spend 23 of cardiac cycle in diast might run out of room so we get two3 of our cardiac cycle we spend in the real relaxation phase that allows us to be able to properly fill the chamber up with blood before it contracts again we want the contraction to be strong quick and Powerful so we want to spend 2third of our full cardiac cycle allowing the chamber to fill with enough blood before it contracts and sends that blood out to the body and that gets us to this question right here why is mean arterial pressure only a relevant calculation at a resting state think about what happens to your heart rate as you go into exercise what's going to happen to the ratio of syy and diast in a cardiac cycle well as you go into exercise your heart rate's going to increase so that means that we're going to spend more time in syy than we do in diast so using this calculation of accounting for systolic blood pressure oneir and diastolic blood pressure 2/3 is no longer relevant at that point when your heart rate is not at a resting state the way that we control all of our blood pressure is through Vaso constriction and vasod dilation so where we don't need the blood we're going to constrict the blood vessels down and then where we do need it we're going to dilate open the blood vessels up so that it kind of shunts all of that blood it redistributes it to the active tissue where we need the oxygen demand the hypertension is something known as high blood pressure so Hy attention if we have our heart right here and aorta comes out and it's sending blood out through the body to our systemic circuit as we get closer out to the extremities the blood vessels get smaller hypertension is this constant 24 hours a day BL high blood pressure which because of that you're putting a lot of back pressure on the left side of the heart so we'll split our heart again here it's coming back to the left atrium and the left ventricle here there's a lot of pressure that the left ventricle has to overcome to get blood to go in that direction out to the periphery so because of that your heart never gets a break hypertension it goes 24 hours a day it's different than the blood pressure increase that comes from exercise so because of the lack of break that your left ventricle gets you end up experiencing left ventricular hypertrophy because the left ventricle has to work hard harder and harder to overcome that greater amount of back pressure or that greater amount of afterload it's going to end up growing in size it's going to get bigger and stronger initially that increase in cardiac mass is a good thing that's going to help us to work more effectively and more efficiently but over time as the heart continues to grow on the left side in Mass it can lead to heart failure the reason for that is draw the picture here if this is my heart right atrium right ventricle left atrium left ventricle this is the muscular wall here of my left ventricle it's going to grow so this is what it looked like originally I'm just going to roughly shade this in this is my muscular wall of my left ventricle here because of the chronic hypertension and my left ventricle has to keep working harder and harder to pump blood get overcoming afterload Lo and send it out to the periphery it's going to get bigger and stronger there's only a certain amount that your ventricular wall can grow outward and when it reaches its limit it's going to start growing inward so now let's say my muscle wall get rid of that my muscle wall grows to this size so all of this shaded in area now is muscle mass of my left ventricle so what does that do to the internal chamber size if my heart is growing inward because of the hypertrophy there then I get a decrease in the chamber size which means that I get a decrease in my indolic volume so I'm not able to fill the chamber up as much with fluid with blood in this case before it contracts and sends that blood out to the heart or out to the body so because this is decreased right here I'm not able to supply the demand which is considered heart failure I'm not able to pump enough blood out to my periphery to supply the metabolic demand of oxygen here's your values here's your values of uh blood pressures here so these are the updated values for normal blood pressure when we're talking about cystolic your top number we want to see that less than 120 your bottom number less than 80 elevated blood pressure is 120 to 129 on your top number less than 80 on your diastolic stage one hypertension is considered 130 to 139 or 80 to 89 on your diastolic and then stage two is 140 or higher on systolic and 90 or higher on diastolic it used to be just generally accepted that anything greater than 140 over 90 would be considered hypertension but because of the state of um cardiovascular health in the United States we've updated this to give these values here for stage one which is also known as pre hypertension but once you get over 140 over 90 or greater then we're actually in the diagnosed stages of hypertension hypertens crisis is when you get systolic greater than 180 and or diastolic higher than 120 there these are the big numbers that we want to look for is we want to see blood pressure 120 over 80 or below we want to see it under that and when we're talking here normal range 100 to 129 on uh systolic 70 to 80 on diastolic so when your blood pressure is within those ranges that's what we call noro tensive so we have hypertension we're just going to abbreviate here hypertension is high blood pressure when it's in with within the normal ranges that's normotensive when you have low blood pressure that's known as hypo tension so that would be values that are below these lower ends of the ranges right there and we don't want to go into that situation as well now ACSM the American College of sports medicine gives us a blood pressure limit so the max systolic blood pressure that we want to see um or our cap on blood pressure during exercise on systolic is 250 millimeters of mercury of pressure and then for diastolic it's 120 so anytime you see those values right there that's what we call an absolute Contra indication so an absolute contraindication to exercise so what that means is if you see either one of these on systolic or diastolic blood pressure we immediately stop exercise it's an absolute stop to exercise and then on the on the hypo side the low side we don't want to see systolic down at 70 mm of mercury that's again an absolute contraindication for exercise we immediately stop exercise at that point when blood pressure gets this low right here below 70 millimeters of mercury of pressure we're not creating enough pressure to be able to send Blood Out to the periphery and get it to circulate back to our right side of the heart so abnormal values we said hypertension earlier hypotension we said was below the lower ends of our acceptable ranges there when we're talking about hypertension there's two different types you have type one and type two right here type one it's known as essential hypertension essential hypertension is is where we don't know what the exact cause of the high blood pressure is whereas this one right here secondary hypertension we have an identifiable cause so this could be a lot of different factors it could be a high high sodium in take it could be you know an increase in body weight there's a lot of different factors you could have if there's an increase in alcohol consumption that's going to lead to an increase in blood pressure so there's a lot of different factors that we could identify that say Hey this is what's causing your blood pressure to be elevated it's secondary to something else whereas essential we don't know what the exact cause is now when we're talking about hypertension some of the side effects and signs and symptoms to look for severe headache that's becoming uh because of an elevated pressure within the blood vessels inside the brain and the cranial cavity can lead to fatigue or confusion vision problems think about how tiny the blood vessels are within your eyes so if you increase the pressure within those blood vessels that can lead to blurry vision chest pain absolutely difficulty breathing because of the increase in the pressure of the blood vessels within the lungs irregular heartbeat blood in the urine so remember that your kidneys are responsible for filtering uh the body fluid in the in the urine and everything that passes through so as the blood vessels within the kidneys get extra pressure within them that could cause some of the blood to leak into the urine and then pounding within your chest neck or your ears sometimes will be able to identify hypertension is when you get that kind of ringing in your ears or you even hear a pulsing in your ears is because think again these are very tiny very tiny blood vessels there so if you increase the pressure within them it's going to disturb the normal function we'll come back to this right here talking about the factors that increase blood pressure um on a question at the end of this PowerPoint so here's blood pressure and some factors here if blood volume increases think if this is my blood vessel right here my tunnel size stays the same but if I increase the total amount of volume of fluid that has to flow through the tunnel it's going to increase the pressure within that tunnel as the blood is flowing through here and creating sheer stress if heart rate increases that means that there's more blood being ejected by the heart per minute so that's more fluid going through the tunnel again same thing with stroke volume more fluid going through the tunnel if blood viscosity increases so viscosity is the fancy word for the thickness of the blood so if the blood gets thicker it's harder to pump syrup through the tunnel than it is to pump water through the tunnel so what that does is it creates more pressure within the tunnel creating afterload coming back on the heart and then peripheral resistance if that increases then we have a major change in our blood pressure what that means is if this was the original diameter of my blood vessel and then it shrinks down it constricts to this size and I have five lers of fluid going through each one of these tunnels which one is going to have more pressure within it the smaller blood vessel is going to have more pressure because there's more fluid trying to pump through that smaller vasculature where hypertension comes from and our blood pressure if we take cardiac output or represented by q and multiply that by the resistance within the blood vessel then we end up getting our blood pressure here if either one of these change then that changes our blood pressure it increases our blood pressure so if we increase the amount of blood pumped per minute blood pressure is going to go up or if we increase the resistance within the vasculature blood pressure is going to go up the reason for that is if if we look at blood flow blood flow is determined by the difference in pressure divided by resistance so we can also write that like that write that as the difference in pressure divided by resistance there resistance is going to come from the length of the blood vessel multiplied by the viscosity of the fluid the thickness of the fluid divided by radius to the fourth power I'm going to put two big stars right here because this right here radius to the fourth power is the number one factor that's going to influence the resistance which is going to be the number one factor that influences your blood flow so if you are asked a question which of these factors has the greatest influence on blood flow and blood pressure it's going to be radius and the reason for that is radius is accounted for four times where these are only accounted for once here we'll see why in just a second but blood flow can be increased by either increasing your blood pressure or decreasing your resistance so by decreasing the resistance if we take our radius if this is our blood vessel and we open the blood vessel up we're making this greater so we're decreasing uh the resistance to our flow which if you drop your bottom number in the formula there then your overall blood flow is going to go up so the difference in the pressure between the arteries in the veins is what's driving your blood circulation to go all the way from the left side of the heart back to the right side of the heart we'll see a schematic of that in just a minute but this is reiterating what we saw on the previous slide here so blood flow is determined by the difference and pressure divided by resistance so ohms law right here of resistance says that viscosity times length of the blood vessel divided by radius to the 4th power so look right here this is my artery um at a resting state this is Vaso constriction this is vasod dilation so if we open the blood vessel up we're increasing the radius here of your blood vessel we're going to get a huge drop in the pressure within this blood vessel as the blood is flowing through that tunnel so this right here is very important that says a very very small change in the radius has a very large effect in total blood flow that's how we regulate and redistribute our blood throughout the body it's going that's going to be very important for talking about what happens during exercise what adaptations do we see during the recovery phase of exercise and it's going to also come back into play in unit four when we talk about how do we regulate our body temperature because we have to get rid of that internal body heat that's being built up from the metabolic processes so again going back to what's the driving pressure across your systemic circuit as blood leaves the left ventricle we're red on red here so it's hard to see as blood leaves the left ventricle it's about 100 millimeters of pressure for our mean arterial pressure and then this right here is the level of capillaries where all the nutrient and gas exchanges are going to occur then as blood gets to the capillaries it maintains that 100 millim of mercury of pressure then we exchange everything that we need at the capillaries it leaves the capillaries and gets back into the veins and comes all the way back to the right atrium by the time it gets back to the right atrium through the veins the pressure drops to about zero millimeters of mercury pressure that's why those one-way valves are so important we don't need oneway valves in Our arteries and arterials because we have pulsatile flow we have new w waves of blood that are forcing that blood to go all the way down to the tissue but as it leaves the tissue and comes back it's at a very low pressure so we have to have these one-way valves systematically put in here so that it prevents the uh blood from going in the opposite direction we don't want it to go backwards and create back flow so this pressure difference of 100 dropping to uh 0 millim of mercur pressure is driving that blood to go from the left side of the heart back to the right left side of the heart back to the right it's all about pressure differences within the cardiovascular system and the respiratory system both of those systems are going to function because of differences in pressure and everything always moves we'll write it up here it moves from I can spell moves oh moves from high pressure to low pressure that's how pressure differences and pressure gradients work so what we've done is we've established this gradient moving from our left ventricle back to our right atrium and that's driving that blood to circulate through your body look at this right here and and just take a second to identify what we're looking at so we have different blood vessels so left ventrical moving into your large arteries we could say the aorta here into your arterials down to the capillaries venal and then back into your veins coming back to the heart what we have on the Y AIS is the pressure here where do you notice we see the greatest drop in pressure so starting with this right here moving over to your veins where do we see the greatest drop in pressure we see the greatest drop in pressure draw these dotted lines right here at the level of the arterials look at the slope of the line and how it's dropping a ton of pressure as it's moving closer to your capillaries why do we do that think about your capillaries so capillaries are they big or are they tiny capillaries are very very very tiny they're only about one cell thick and it allows one blood vessel or one red blood cell to pass through at a time so that we can exchange oxygen and CO2 like we need to we have to drop the pressure within the blood vessels significantly at the level of the arterials to prep that blood to slow the blood down as it gets into the capillaries we do not want a lot of pressure within our capillaries because they'd rupture and we want to slow the blood down so we have enough time for oxygen and CO2 to exchange the nutrients can exchange we can get the byproducts out of the tissue the hydrogen the lactate and all of that stuff and push it into our venules and then further into our veins to get it out of our active tissue so we see the greatest drop in pressure at the level of the arterials to prepare the blood to enter into the capillaries where all of the exchange is going to occur now what happens with exercise so all of these variables are going to see drastic changes when we go into exercise because we have to adjust everything that we do so that we can supply the demand especially with the oxygenated blood but also getting all of the byproducts out of the tissue so what's going to change we see that all the variables we've talked about so far are going to change heart rate stroke volume cardiac output blood distribution blood pressure why do we do that to meet that metabolic demand to provide more oxygen get rid of all the waste products and help regulate our body temperature so when we talk about our heart rate here what we want to see resting heart rate is 60 to 80 beats per minute now 62 of the reason 100 is in parentheses here 62 100 is consider considered normal heart rate that's the acceptable heart rate range but what we really want to see is 60 to 80 the lower the heart rate at a resting state the better that's why we see end up highly trained athletes marathon runners and those that are cardiovascularly trained can have resting heart rates down at 30 to 40 beats per minute because their heart and their cardiovascular system is working so efficiently but when you flip the script and go to the sedentary population the physically inactive it's not uncommon to see heart rates at a resting level at 100 beats per minute anything greater than 100 beats per minute is what we call tardia which is just meaning a high resting heart rate anything less than 60 beats per minute is known as bradicardia which is just a low resting heart rate what we want to see is between those values 60 to 100 now exercise is going to cause your heart rate to spike so if we graph that here if this is our heart rate and this is our exercise intensity as exercise intensity is increasing along the x-axis here what we're going to see is heart rate increases in direct proportion to exercise intensity so there's a linear uh relationship between those two variables there that's why we use heart rate all the time to estimate what exercise intensity is so what we end up seeing is heart rate will increase all the way out until what we call your max heart rate and we can estimate that by a couple of different ways the most common and kind of the old uh generic way of estim ating your max heart rate that you can achieve is 220 minus your age so if you are 20 years old then the estimated max heart rate you'll achieve during exercise is 200 beats per minute the newer formula and what's being pushed more in the industry is the Tanaka formula so Tanaka formula says we're going to take 208 minus 0.7 times your age it gives you a little bit more of an accurate representation of Max heart rate um that we've seen over the last decade of research with exercise heart rates but this is going to change uh as you get older but it's constant from a day-today perspective so why is Max heart rate so highly related to age in other words it's age dependent why is that you have all of these receptors within your cardiac tissue known as beta receptors beta receptors are responsible for being stimulated to increase your heart rate now as you get older your beta receptors become less sensitive so it's harder to actually stimulate the heart tissue to get elevated heart rates up there around 200 beats per minute like you could when you were 20 years old so the reason that the your max heart rate is so highly related to your age is because of the desensitizing of your your beta receptors within your cardiac tissue now when you change your um exercise intensity we're going to reach something called steady state fairly quickly which that's a good thing that means that we're actually supplying the demand so say I go from rest down here and I start exercising but I don't increase my intensity past this point let's say this is 60% of my Max Capacity what I'll end up seeing if I get to that point so I increase my intensity to that point and then I just kind of level off and maintain that intensity my heart rate is going to plateau and it's going to level off with the intensity as long as I maintain that exercise intensity my heart rate will stay at steady state meaning that I'm supplying the demand sufficiently within that exercise session now what I'll end up seeing seeing those if I bump my exercise intensity up so say I've been doing 60% for 7 or 8 minutes and then I bump my exercise intensity up I'm going to see my heart rate increase with that exercise intensity and then as long as I maintain it at say 70% for the next one to four minutes I'm going to get to steady state again and it's going to plateau and level off meaning I'm supplying the demand so we see that here treadmill speed representing your exercise intensity heart rate's going to increase in direct proportion with exercise intensity until you get up there to your heart rate Max now like we said earlier heart rate is a very common variable used to prescribe exercise intensity because of the close relationship between the two so that's why we do something called the target heart rate so target heart rate this is a very simple technique for prescribing exercise intensity I'm going to take your max heart rate so 220 minus your age and say I want to prescribe a heart uh an exercise intensity of 75% of your max heart rate so I'll take 75 here and multiply that by your age predicted max heart rate and that's going to give me a value of 150 beats per oops beats per minute if my age is 20 years old so 150 beats per minute is 75% of my max heart rate that can be a way that we can prescribe exercise but if I'm doing something I want to be a little more precise I'm going to use something called the caronan heart rate Reserve method so that hrr stands for heart rate Reserve what we do with heart rate Reserve is you'll notice we're taking into account that individual's uh resting heart rate so it's becoming relative to that person because we're taking into account an individualize Factor everybody's going to have different resting heart rates so this is going to allow me to be as as individualized as possible when I'm writing my exercise prescription so the way that we do this is we take Max heart rate so again we can use 220 minus age or we can use the Tanaka formula if we want want to be as accurate as possible but we'll take Max heart rate and let's just do an example here and say that we have an individual that 20 years old and that puts their max heart rate at 200 and they have a resting heart rate of 60 beats per minute so rhr resting heart rate is 60 so we're going to plug in 60 here and 60 here if we do all of the math we're going to to end up getting 140 so 200us 60 is 140 we'll take 75% of that and that's going to get us uh 105 so let's do this over here do max heart rate minus resting heart rate so that was 200 resting heart rate is 60 that's going to get us 140 uh 140 multiplied by the 0.75 representing our 75% is going to give us a heart rate of 105 beats per minute but you'll notice at the end of the formula anytime you're doing a reserve technique you always have to add the resting value back at the end so we have 105 plus our resting heart rate of 60 that's going to give us a target heart rate of 165 beats per minute do the same math down here we have 200 minus our 60 gives us the 140 again 140 multiplied by 85% gives us uh 119 and 119 oops 119 plus our resting heart rate at the end right here you can't forget to add that back at the end gives us has a target heart rate of 179 beats per minute now what I've done is I've established a range for this individual to exercise so I want them to exercise between 165 beats per minute and 179 or roughly 180 beats per minute why is that more beneficial from an exercise prescription standpoint as compared to doing something like this and say and I want you to exercise at 150 beats per minute if any of you track your heart rate when you exercise think of what does your heart rate do as you're exercising even though you're not changing your speed of your run or the intensity of your lift your heart rate is going to fluctuate it's going to go up it's going to go down I watch my heart rate all the time uh even at a resting state but especially when I go out for a run I love to watch what my heart rate's doing and notice that my heart rate goes up and my heart rate comes down comes back up goes back down you're not going to be able to keep it strictly at 150 beats per minute so by establishing a range now I can keep my heart rate between 165 and 179 or 180 that's easier to do because it's going to fluctuate automatically no matter what you're doing even though I'm not changing my pace of my run it's going to go back and forth forth up and down and ride that wave now from a professional standpoint or if you're a clinician you're a personal trainer you're uh in physical education you're in physical therapy whatever you're doing that's related to exercise if think about how difficult it is from somebody from a physically inactive lifestyle from the general population where most people lead a physically inactive sedentary lifestyle think about how difficult it would be if you're the professional and you tell them I want you to go exercise at 150 beats per minute so they go out and they try and do that and they see that their heart rate goes up to 160 and then they're like okay I need to slow down a little bit and it drops to 130 and then it bumps back up to 158 and then down to 142 from a perception standpoint they're thinking I can't do this my professional my PT my my trainer whoever it was told me I needed to be at 150 beats per minute but I can't do it that creates a negative perception of the exercise and now I've created a barrier to that exercise and they're not going to want to go back and do it but if I use a heart rate range and take into account their resting heart rate and I say okay go exercise between 165 and 179 beats per minute now they can actually work out and exercise within that heart heart rate range because they can keep their heart rate within that range I've created a positive perception for the exercise so now I've reduced the barriers to exercise and they're going to come back and do that session again because they feel good about it they feel successful in doing what the quote unquote professional told them to do so there's uh reasons for using the heart rate range and especially using a reserve technique which takes into account the r in value there I always want to be as accurate as possible when it comes to working with an individual the other benefit of doing this is if I were to use just our regular um 75% so say I tell everybody in the class to go exercise at 75% of Max heart rate okay well let's say everybody in the class is just hypothetical here everybody in the class is 20 years years old so age predicted max heart rate would be estimated to be 200 beats per minute okay everybody go exercise at 75% of that that's going to be 150 beats per minute well what if your resting heart rate is 60 beats per minute and the person next to you their resting heart rate is 90 beats per minute who is this exercise more difficult on it's going to be more difficult on the person that has a resting heart rate of 60 beats per minute because I have to go from 60 all the way to 150 where as the person next to me has to go from 90 to 150 so not as much of an increase in their heart rate as compared to the person with the lower heart rate but if I take into account your resting heart rate in this Caron's heart rate Reserve technique now 75% becomes the same intensity no matter who it is because we're taking into account and factoring in your individual resting heart rate there all right so what happens with stroke volume and exercise so stroke volume is going to increase with exercise intensity up to about 40 to 60% of your Max Capacity um the reason for that is if we look at stroke volume right here we're going to flip back and forth between slides as exercise intensity represented by treadmill speed is increasing there we can see that it's going to increase to about 40 to 60% of the Max and then it plateus off why is that is because as your heart rate is increasing there's not as much time in diast to fill the chamber back up with heart before the next cont or fill the chamber back up with blood before the next contraction and also as you get closer to your max heart rate you're increasing your exercise intensity more more you're maxing out your contractility the strength of the contraction so stroke volume is going to plateau and go down there now why is having a higher stroke volume in Advantage the reason for that is because everybody if we draw our graph again this is our exercise intensity everybody can increase heart rate out to their max heart rate so this is our heart rate right here so everybody's going to increase their heart rate similarly it's going to linear proportion linear relationship between heart rate and intensity there so having a higher stroke volume is an advantage because if everybody's heart rate is going to increase the same if I have a higher stroke stroke volume than you do our heart rate may be the same but I'm ejecting more blood out of the left ventricle per contraction so I'm going to be able to supply more blood to the uh active tissue so a bigger stroke volume leads to more cardiac output which is more blood being Pres presented to your muscles during exercise now factors that influence your stroke volume with exercise one is going to be the amount of blood that's coming back in the Venus return back to the right side of the heart which is going to then affect your Frank Starling mechanism somebody who has a larger uh ventricle is going to be able to fill the blood or fill the chamber with more blood per contraction so we're going to get more blood going out to the body and then if you decrease that total peripheral resistance there's less pressure being pushed back on the heart meaning that after load is lower so I'm able to create more pressure in the opposite direction and send Blood Out to the body and that gets us to cardiac output remember cardiac output is your heart rate times stroke volume so what did we say earlier if heart rate increases with exercise intensity and stroke volume is going to increase all the way to about 60% of your Max Capacity what do you think is going to happen to Q cardiac output is the amount of blood being presented to the working muscle made up by these two variables that are both increased so that means that cardiac output has to increase as well so what happens at that kind of 40 to 60% of Max Capacity when stroke volume plateau is off so let's draw it further out so stroke volume at about 60% of Max Capacity is going to platto off heart rate at that point is the only mechanism that can continue to increase cardiac output so say you get to 60% of your Max Capacity stroke volume levels off we have to get heart rate to increase more so that we can keep our cardiac output up to supply the oxygenated demand to the tissue that's that's what's known as cardiovascular drift so what we'll end up seeing let's draw it down here this is my stroke volume so stroke volume's increasing and then it plate off heart rate increases in the same manner but when stroke volume plateus off heart rate has to pick up the slack so that we can maintain cardiac output so we're going to see that heart rate will actually start to increase disproportionately to your exercise intensity because this guy stroke volume is plateaued heart rate has to compensate for it to be able to maintain Q so if we draw Q through here this would be our cardiac output we want to maintain Q so that we can supply the demand during exercise there so here's cardiac output just kind of showing you how the trend of everything it increases and then right around here is where we see the stroke volume volum is going to Plateau off so heart rate uh to maintain cardiac output there heart rate has to increase disproportionately so that we can keep cardiac output steady and present the tissue with enough oxygenated blood to keep going another example here of cardiac uh cardiovascular drift and maintaining cardiac output stroke volume plateaus or even drops off during strenuous exercise because think about What's happen happening as I'm getting into that exhaustive bout of exercise I'll see that uh a lot of my stroke volume is being lost because of body sweat so I'm sweating to dissipate that body heat uh the sweat comes from the plasma volume in your blood so my blood's getting thicker which means that it's harder to pump with each contraction so my heart rate is going to increase disproportionately to uh compensate for that all the way out but you'll notice right here when exercise gets very strenuous that cardiac output starts to fall away from that steady line why is that well the reason for that is heart rate can't increase indefinitely it can only increase out to where you get to your max heart rate once you get closer to that Max heart rate we're decreasing our stroke volume and our heart rate is going to level off it can't increase any further so because it can't increase and compensate for this drop in stroke volume we're going to see that cardiac output starts to fall at that very high intensity and extreme bout of exercise with blood plasma volume um initially when you start exercising you're going to start to lose some of that plasma volume into the interstitial spaces of your tissue so think of my blood vessels my blood vessels dilate within my active tissue and then that active tissue contracts so when it contracts I'm squeezing down on this dilated blood vessel which forces some of that fluid to leak out into the interstitial spaces that's why if you remember we talked about transient hypertrophy the muscle pump that happens when you're exercising when you're lifting weights um now as you continue exercise you'll actually see that you start to lose more of your plasma volume because of sweating so that's why an excessive amount of fluid loss can lead to a decline in performance because you're increasing the viscosity viscosity of your blood which makes it harder to pump it's a thicker blood so it's harder to pump through your vascular system to get to your exercising tissue so because of that making it uh harder to pump decreases our performance in a longer duration now uh the reduction in the plasma volume leads to a hemo concentration so if you remember from lecture one in cardiovascular we had that vial of blood and we said that 55% of your blood volume uh total blood volume is plasma and then 45% is hematocrite in other words all the formed elements within your blood so if you start to reduce this plasma volume so we lose plasma volume because of sweating our hematocrit is going to increase we're going to have a thicker blood because of all these formed elements the red blood cells the white blood cells the platelets and all of those clotting factors and everything else so that's what hemo concentration is I'm concentrating my blood in other words I'm it's not as diluted as it was previously with that plasma volume so technically yes it increases the oxygen carrying capacity of the blood because your your red blood cells are more concentrated in your total blood volume but because of that increased viscosity it's harder to pump that concentrated blood through your vascular system so can exercise training change your blood volume the answer is yes and what endurance training can do is it will lead to an increase in overall total plasma volume the reason for that is because we lose a lot of our plasma volume during exercise from the sweat mechanism but over time our body becomes adapted to that exercise and we won't sweat as much so what we end up doing then is we retain more of our plasma volume which increases the amount of plasma within your total blood volume so we get more uh of a a decrease in viscosity making our blood thinner so it's easier to pump through our vascular circuit and Supply that blood to the uh exercising tissue and what happens to blood pressure during exercise systolic blood pressure we know that that's going to increase because our heart rate increases stroke volume increases which means cardiac output increases the amount of blood that is leaving our left ventricle per minute is significantly going up so we're forcing more blood to go through this little bitty tunnel so that's going to increase the pressure within that tunnel during the contraction phase of the cardiac cycle now with diastolic blood pressure we really don't see that much of a change in di diastolic blood pressure during exercise um sometimes you'll even see that uh DPP DBP diastolic blood pressure decreases slightly why is that think about what's happening in your blood vessels if I'm going through exercise say these are my legs the muscle mass in my legs and I have all of these blood vessels going through the muscles in my legs and all of these blood vessels during a leg exercise something like running all of those are going to dilate because I need to supply more blood to that exercising tissue if I dilate all of these blood vessels within my legs then I'm opening up all these tunnels which is going to allow a big Rush of Blood to go to the muscle mass in my legs and that's going to decrease the amount of pressure within my vascular system because I'm opening up all these tunnels if I open up the tunnels I'm relieving some of that pressure some of that afterload that's coming back to my heart so sometimes during exercise you'll see that diastolic blood pressure the blood pressure during the relaxation phase of the ventricles in the cardiac cycle is going to decrease just a little bit now with resistance training you can see very high blood pressure so exaggerated blood pressures um during a lift blood pressures can go up to four times what they normally would be at a resting stage so remember resting blood pressure we really want to see it around 120 over 80 so during resistance training we can see an increase of fourfold there on the systolic side why so high is most people use things like the Val solva maneuver during resistance training so not only am I dilating the blood vessels getting more blood going to my muscle and then Contracting that muscle down on those blood vessels meaning I'm squeezing down on these blood vessels and increasing the pressure within them I'm also if I use Val Salva maneuver technique I'm holding my breath against I'm trying to force air out against a closed glotus which is going to increase the pressures within my vascular system because it's going to close off some of my oneway valves it's going to prevent or it's going to prevent blood from coming back to the right side of my heart if the venne cavas close off and that's going to create this uh back pressure going back through your blood vessels and overall increasing your blood pressure to a drastic amount and what's the difference between arms and legs when comes to blood pressure and exercise believe it or not when we talk about how do these relate to one another arms represented in red whereas the legs are represented in green think about the size of the blood vessels and the amount of muscle mass and the difference between the two so we have much more muscle mass in our lower body and the size of the blood vessels are larger in our lower body so when you do leg exercise because you have more blood vessels and they're bigger in the lower body you have more blood vessels that are opening up and dilating because there's more of them and they're bigger and they're dilating it's relieving a lot of that pressure within your vascular tree so when we talk about the comparison of arm exercise to leg exercise we actually see a greater increase in blood pressure with arm exercise than we do with leg exercise mainly related to the size of the blood vessels and where your muscle mass is located so if I go do a bench press I need to be able to dilate the blood vessels in my upper body and I need to constrict the blood vessels in my lower body I have more blood vessels and larger blood vessels in my lower body so I'm constricting those down which is going to create a lot of back pressure coming back on my heart because the blood vessels in my upper body are smaller and there's less less of them there's more pressure coming back which creates this exaggerated blood pressure increase for the arm exercise when I do my leg exercise there's more blood vessels down here and they're larger so when I open those up to supply the oxidated blood to my lower body and I constrict these I'm actually relieving some of the pressure within my vascular system so blood pressure changes um um is a little bit smaller with leg exercise as compared to the arm exercise there now this gets us to a variable that's very important in exercise physiology known as avo2 difference so av2 difference stands for the arterial venus oxygen difference and what we're looking at here is that this is my artery coming down so let's just say this is artery this is getting down I guess I should draw it smaller so it's getting smaller here in the arterial and then it gets down into the capillaries within my muscle tissue and then I have venol leaving my muscle and they get bigger and become veins so venules and veins what avo2 difference is is is the difference in the oxygen content between the arteries and the vein so how much oxygen was uh presented to the muscle tissue and how much oxygen is in the blood as it leaves the muscle tissue what this tells us is how much blood was or how much oxygen was extracted out of the blood as the blood passed through the muscle itself so it says here how's it calculated we're going to take the arterial the artery O2 content minus the Venus O2 content and whatever that difference is between the two tells us how much O2 was extracted out of the blood within the muscle tissue as we go into exercise we'll see that avo2 is going to increase so as exercise increases we see a concomittant increase in av2 difference and that makes sense because as your exercise intensity or duration increases we're going to need more oxygen going to that exercising tissue so we want a greater difference between these two meaning and what that means is we've extracted more oxygen out of the blood as it passed through the muscle so that last variable down here avo2 lets us calculate something called V O2 so V2 is the volume of oxygen being consumed by the tissue and the way that we get that is take how much blood was presented to the tissue cardiac output so how much blood is pumped per minute in other words how much is taken to the tissue multiply that by how much blood how much oxygen is extracted out of that blood as it passes through the tissue and that tells us the volume of oxygen being consumed at the level of the tissue every minute now this is separating the formula here so we have this ore I put ore here because I don't want you to think it's Q * av2 equals heart rate time stroke volume time avo2 these are separate formulas remember cardiac output is made up of heart rate time stroke volume so this is just a different way to write it right here you could write it as Q * av2 or heart rate times stroke volume you're breaking down cardiac output there times avo2 very important equation to know right here so big star on fix equation make sure that you understand what fix equation represents and how it relates to V2 the central command Theory gives us an indication about how do we regulate our heart rate so what it says here is within one second after the initiation of exercise we'll see that we start to withdraw the parasympathetic control of our heart so if I if we have our heart rate and say our resting heart rate is 60 beats per minute the reason that our heart rate at a resting state can stay so low is because the parasympathetic system is is in control of your heart rate if you remember from unit two remember us talking about depolarization threshold so we have resting membrane potential and then we have our depolarization threshold and as the resting membrane potential gets up here due to depolarization threshold we get an action potential that happens we can stimulate the tissue that's the same thing that's happening with our cardiac tissue but what happens when we're under parasympathetic control is our resting membrane potential is dropped so it's further away from depolarization threshold making it harder to stimulate because you can see that it's it it takes a stronger stimulus to get from all the way down here to depolarization as compared from right here to depolarization so when we're under parasympathetic control that's something called vag tone and the reason that we call it that is is because it's controlled by the vagus nerve which provides that kind of parasympathetic hypop poiz so when we drop the resting membrane potential down that's hypo WR it here hypo whoops polarization because it's below normal so parasympathetic control is keeping your heart rate low as I start to exercise what I do is I start to withdraw that parasympathetic control off of my heart which lets my resting membrane potential creep back up here closer to depolarization threshold meaning it's easier to stimulate the tissue at that point so my heart rate at that point is going to start to increase a little bit now if I need my heart rate to increase anym typically if I need my heart heart rate to go above 100 beats per minute that's where sympathetic nervous system comes into play and we get the influx of those catac colomines kind of that adrenaline rush and it makes your heart rate Spike up even more what Central Command Theory says is that initial signal um to the cardiovascular system at the start of exercise to allow you to start increasing your heart rate comes from a higher brain Center and then then what we do after that is we rely on receptors out in the body to fine-tune that cardiovascular response so let's look at it right here so say I'm going from a resting state into exercise my Central Command higher brain centers are going to send a signal to my cardiovascular Control Center and say hey let's start to remove that remove that parasympathetic control and let our heart rate increase a little bit so now I'm getting more blood circulating through the body I'm supplying the demand so I'm sending uh signals out to my heart to increase my heart rate and I want to dilate my blood vessels in the exercising tissue constrictum in the inactive tissue now as I continue the exercise I'm going to get feedback coming from receptors out in my periphery and they're going to send information back and say either say look you're doing great you're supplying the demand we don't have to increase heart rate anymore so let's just level it off let's let's maintain steady state here or they may send information back and say hey I need more oxygenated blood coming to the tissue I'm changing my pH here so I need to get oxygenated blood flowing through this tissue to get the hydrogen out and Supply oxygen to my muscle tissue so I need you to increase your heart rate a little bit more so that feedback coming to the cardiovascular control center will end up dictating whether I need to increase my heart rate I need to just maintain it or you know hey I've got more than what I need so I can decrease my heart rate at this point and I'll be still be able to supply the demand all right our last couple of things here um related to vascular remodeling so as you exercise one of the adaptations a major adaptation that you can see is changes in the structure of your blood vessel so what we can end up seeing over time if we maintain exercise habits is we can see not only do Our arteries and arterials get larger meaning that we can supply more blood to that tissue and it drops the pressure within the blood vessel so that's the reason your blood pressure is going down from exercise training uh and the benefit there and the other thing that we'll see is an improved ability to dilate your blood vessels so now as I send more blood through the tunnel and I create that sheer stress I'm going to release that nitric oxide that we talked about in our first lecture of cardiovascular and I'm going to be able to dilate to a greater capacity I can get more blood through this larger tunnel and it's not stressing my blood vessel as much and potentially leading to damage overall that decreases resistance remember resistance is the number one radius is controlling resistance or the number one factor um influencing resistance and resistance is the factor that's going to be related to your blood pressure so that's the major reason that we see drastic changes in blood pressure due to exercise training our blood vessels have this ability to create something called collateral circulation and the reason for that is because your blood vessels are known as anasto otic blood vessels especially around the heart the vasculature that supplies oxygenated blood to your uh myocardium so anastomotic blood vessels means that they have the ability to change they can grow we can Branch off so if this is my original number of capillaries here I can actually Branch off and create new capillaries within the tissue that's a mass massive benefit to allow me to be able to supply blood to more tissue in your heart tissue it's an excellent protective mechanism to prevent an es schic myocardial infarction uh which in other words is just a heart attack coming from a lack of oxygenated blood so let's look at heart attack right here what happens under normal physiology we see these coronary arteries are coming all the way down to the apex of the heart and they're supplying oxygenated blood to The myocardium itself and then the veins are bringing it back into recirculation but if you get an occlusion this little blockage right here in this artery I'm not able to supply oxygenated blood at any point beyond that blockage so what that does is it leads to esia which is a lack of oxygenated blood and if we don't have oxygenated blood going to the tissue the tissue is going to die that's why it says here this is the area of myard infarction and cellular death so this is what's leading to chest pain in a lot of individuals um and can be a early indication of a heart attack that's going to happen but what our coronary blood vessels have the ability to do is create collateral circulation so picture a here is an open blood vessel normal function allowing blood to pass all the way through down to the apex of the heart but as we start to get say plaque build up within these coronary arteries that's an oclusion and it's restricting blood from passing through here and continuing on down to the apex of the heart so you can see right here this area is not getting oxygenated blood and that's why it's shaded right here showing you this esic area of myocardial tissue what your coronary blood vessels will will do is they start to see that and they'll start to grow and they'll branch and they'll attach to one another creating this bypass network of blood vessels to allow oxy blood to continue on and get past this occlusion and down to your tissue this is an 100% occlusion a total occlusion of your blood vessel right here and you can see that the capillaries have branched and they've gotten larger in diamer to be able to allow blood enough blood to pass around that occlusion and Supply blood all the way down here at any point past that occlusion so so it's a definite benefit uh of what the blood vessels can do within the body but one thing that we do know is exercise regular exercise automatically stimulates collateral circulation so by doing exercise you can actually protect yourself even in the presence of plaque buildup and occlusions like this right here even in the presence of that exercise is already St stimulated this uh collateral circulation using your anastomotic vessels and it allows you to bypass that so that we can actually prevent that myocardial infarction from happening in the future everybody's seen something like this before um and hopefully you're familiar with the term of what this is called this is known as varicose veins varicose veins you typically see in the lower body we don't really see it in the upper body and the reason for that is because gravity is constantly pulling blood back down towards the foot so what can you think of would cause varicose veins if we look let's flip to this slide right here if we look at varicose veins this is normal function right here blood is supposed to pass through this one-way valve and come back up through this one all the way back up to my heart now if I have a disruption a deformity in my one wave valve what ends up happening is blood it tries to pass through here and it's trying to get back up here to my heart but gravity is constantly pulling that blood back towards the feet so because this oneway valve is not closing off what happens is gravity pulls the blood back through here and creates back flow of blood in my lower extremity now the next time these muscles contract and the the pressures change and everything a new wave of blood tries to go through here and it goes up and it tries to get back to the heart and some of it comes back down through the one-way valve uh because it's not closing off so now with every new wave of blood that comes through here it creates this swirling of blood within my vein as the blood continues to accumulate and swirl within my vein it causes distension in other words stretching of my blood vessel of my vein there remember the anatomy of veins is different than arteries and arterials veins don't have that strong muscular wall that smooth muscle around them so they're very elastic in nature so as I continue to increase the amount of fluid within the veins and it continues to swirl in there it's almost like a balloon and it just keeps stretching and stretching and you you can see that displayed right here as it continues to stretch it needs somewhere to go so it starts to actually swirl and it starts to kind of sway throughout the leg there because it's getting longer it's stretching and stretching and it gets longer it gets greater in size so that's what happens with varicose veins is it's coming from this uh oneway valve that's not functioning properly so uh like we said it usually occurs in the lower extremities but this term right here be familiar with in the severe cases of vericose veins it can lead to something known as fitis which is inflammation of the wall of the vein so the Venus wall gets inflamed and irritated and this can be extremely painful so some people that have varicose veins may explain it as this burning feeling within their leg around that varicose vein and that's because there's inflammation within the wall of that vein somebody with varicose vein should avoid static and straining exercises so something like a deadlift where they are really straining and it's a heavy weight and they're creating this kind of a lot of pressure within the vascular tree that should be avoided because what could happen let's get rid of some of this now what could happen is because of of all this pressure through the straining of that vein it could create this little bubble if there's a weak spot in the vein or in the wall of the vein there it creates this little bubble um which could lead to an aneurysm if that ruptures then we have now we have uh a hemorragic situation where we're actually losing blood because of that rupture of the Venus wall That's major reason why warm warming down is so important with exercise we always talk about an exercise warm up so getting the body prepared for exercise but we want to make sure that we warm down we cool down after exercise just as much as we warm up because think about if I go for a run that's a very heavily weighted lower body exercise so I've got a lot of blood that's pulled in the tissue in my lower body by Cooling down or warming down after exercise I'm going to allow my body to redistribute that blood I'm going to pump it out and redistribute that blood equally through the rest of my body if I were to go do this heavily weighted lower body exercise and I've got a lot of blood in my lower body in the veins and I just stop exercising and I sit down then gravity is going to try and pull that blood and keep it in the lower body which can disrupt my one way way valves and end up over time leading to varicose veins the other reason for the cool down is to get rid of all that metabolic waste that's been produced from your muscle tissue during exercise all the hydrogen the lactate everything that's happened within the tissue I want to flush it out and and kind of process it through my body so that it doesn't change things like my pH and everything else within that localized environment all right the last thing that I want you to do here is I want you to go back to that slide earlier when we were talking about blood pressure there's nine factors listed there things like sedentary lifestyle alcohol intake sodium intake potassium calcium all kinds of factors that can affect blood pressure you can be as simple as as possible and go on Google and just look up how does a sedentary life how does alcohol consumption influence our blood pressure and I want you to take five of those nine factors any five that you want and write write it out describe how do five factors affect blood pressure what does say an increase in alcohol consumption due to blood pressure I can tell you that it's going to increase blood pressure but I want you to research why does it do that so always answer the question why this is going to come back later on you'll see this on your uh exam is factors that are affecting blood pressure what does it do does it increase it does it decrease it and why does it do that so I hope you can take this information and put it into play and whatever you do on your everyday routine but make sure you take your time as you go through all of this material and understand it write your questions down and if you have any questions that you want me to answer feel free to send those to me or post them on the canvas page uh in the discussions Tab and I'd be happy to take a look at those