okay so moving on to section seven of chapter 17 we're going to talk a little bit about blood transfusions so our cardiovascular system typically acts to help minimize the effects of blood loss by doing two different things one is actually reducing the volume um being sent to the affected blood vessels and the second would be to increase the production of red blood cells or increase the um increase uh the rate of Arro poesis so even by doing those two mechanisms our body can only compensate for so much blood loss so about 15 to 30% of blood volume loss can cause palor and weakness if we lose more than 30% of our blood volume this could potentially be fatal so again if we have really really low blood volume it can result in shock which can lead to death so in the event that we have massive amounts of blood that we're hemorrhaging and we can't get a transfusion quickly then we want to go ahead and replace the V volume with something like normal saline or a multiple um electrolyte solution something like ringer solution and the whole po purpose of those are to help mimic the plasma electrolyte composition but if we replace it with the saline or an electrolyte Solution that's only going to restore the volume of blood it's not going to help replace the red blood cells that we actually lost so it doesn't help replace the oxygen um carrying capacity of our blood cells so when we're transfusing um red blood cells we have whole blood transfusions these are rarely used and they would only really be used if we're losing massive amounts of blood very very quickly normally um the transfusions are going to be with packed red blood cells or p rbc's and this is going to be whole blood um which has a lot of the plasma and the uh lucaites out of it so those have been removed um if we're talking about blood blanks if we're going to go through and do um donate blood they usually separate the donated blood into compartments also we're talking about shelf life of blood only being about 35 days so human blood groups of the donated blood has to be predetermined um because transfusion reactions can be fatal so if you re receive an infusion of a different blood group than your own it can be incompatible leading to fatality so blood typing is going to determine the blood groups so people have different blood types um and like I said if we get a transfusion of incompatible blood that can be F can be fatal so in the plasma membrane of all red blood cells or ryes we have these little markers that are called antigens several different types and in general we call an antigen um something that can be perceived as foreign and if we perceive something as foreign that typically is going to generate or Mount some sort of immune response if we're talking about antigens or these things that can generate an immune response on a cell we're specifically talking about a red blood cell then we call them a glutenin okay so the antigens that are on the red blood cell membranes are called a glutenin um because they're able to promote a gluten or clumping so if we get a mismatched uh transfused blood that's going to be perceived as foreign and cause um a glutin um and could potentially be fatal so we talking about human blood groups we do um have at least 30 naturally occurring antigens or glutenin on the surface of our red blood cells um the presence or the absence of each antigen type is going to be used to classify the blood cells into these different groups some GL groups such as MNS or Duffy or kale or Lewis they're only weak a glutenin so they're not usually typ because they don't normally cause um um or generate an immune response antigens of the and the RH blood groups um those are going to be the ones that cause the most figur transfusion reactions and so those are the major blood groups that we actually type so let's start with AO blood groups um so these are based on whether or not we have the presence or the absence of two types of a glutens or those antigens and that would be type A and type B so depending on which of these a person inherits he can either have um AB a blood group will either be a b a b or o if we're talking about the O blood group that means that it doesn't have a or b a glutenin and the most common group in North America is actually blood type O if we're talking about type AB that means it has both A and B A glutenin which remember are also called the antigens and if we're talking about type B that has only the type only the B gluten and if we have type A that has only the a gluten so the blood may contain preformed anti-a or anti-b antibodies the antibodies we would call a gluten glutenin and these basically act against transfused um red blood cells with the antigens that are not present in the recipients rbcs so after about 2 months of age is when we start forming the antibodies or the glutenins against the antigens that we don't have on the surface of our red blood cell so I think the best way to kind of understand this is by looking at this table so if we have blood group type AB again that means we have the a antigen and the B antigen on the surface of our red blood cell so here's the a antigen represented as a little triangle and the B antigen is represented as a circle because we're talking about antigens on the surface of a red blood cell we call them a glutenin so because we have the A and the B antigen on the surface of a red blood cell and if we have blood type AB that means we don't want to produce any antibodies against these antigens or else we would be attacking our own blood cells so we have no antibodies which are also called a glutenin now if we have blood type B that means that we have B antigens on the surface of our red blood cell so we can see the little circles that represent the B antigen or gluten after about 2 months of age our body is going to naturally produce the antibody against blood against the a antigen so we have antia or anti antibodies against the antigen a we don't have the a antigen so we would not be attacking our own red blood cells if we have blood type A that means we have the a antigen so now we have the triangle antigen on the surface of our red blood cell and remember antigens are also called a glutenin so we have the a gluten our body after about two months of age will begin producing antibodies against the antigen B because we don't have the B antigen we can produce antibodies against it so blood type A has antib antibodies or glutenins if we have blood type O that means we don't have any of the antigens A or B on the surface of our red blood cell so you can see that however because we don't have the a orb antigen on the surface of our red blood cell we're going to produce antibodies against both of those antigens so floating around in our plasma we're going to have anti a and antib so that's why we have um o as the universal donor o is the universal donor because it doesn't have any anti antig gens on the surface of its red blood cell so it doesn't matter if we have if we give type O blood to type AB b or a even if they have the antibodies against the a antigen and the B antigen they can't attack it because there's no antigen for the antibody to recognize there's nothing on its surface blood type AB is considered the universal recipient um because it has because there are no antibodies in a person's blood that has blood type AB doesn't matter which blood type they receive uh there's not going to be antibodies present in the blood for it to go in and attack and recognize the other blood type as fore so the is one of the blood um groups or describing again the A and B antigen being present or not present on the surface of red blood cell but we also have another antigen or gluten and that's the Rh factor so there's about 5502 named um RH glutenin Each of which we call an r factor only five of them are really common so you might have heard of them um c d e um antigens but when we're talking about the RH blood typing system it's named because of one RH antigen which is specifically the the gluten D or the D antigen here um it was originally identified in a Reus Reus monkey which is why it's called the RH antigen and then later we found out that humans also have this antigen um on this can have this antigen on the surface of their red blood cell so if we're looking at Americans about 85% of Americans are RH positive meaning they have the RH um antigen on the surface of the red blood cell so only about 15% of Americans do not have the Rh factor the difference between um RH blood groups and the blood groups is the antibody formation so if we have we're talking about ab and O blood type um our body after two months is naturally going to produce the antibodies against the antigens that our red blood cells do not have on their surface if we're talking about the r H um antigen our body does not naturally produce the antibody against it if we don't have it on the surface of our cell so the antih antibodies they are not spontaneously formed in an Rh negative individual so we're talking about anti- R antibodies um form only if the Rh negative individual receives RH positive blood or if Mom is carrying ing an RH positive fetus so the second exposure to the RH um positive blood would typically result in a transfusion reaction okay so we have hemolytic disease of a newborn um also called also called athro so what happens is that her antibodies can cross the placenta and actually go to attack and Mark as forign the baby's roed blood cells and it produces this condition the baby can become anemic um hypoxic and in really really severe cases there could even be bearing damage um or even death if we don't have transfusions done before the birth um see what else I have so the first pregnancy if we're talking about this the Rh negative mom is exposed to the RH positive blood um so after her first baby is delivered because the mom has been exposed to the RH positive blood she's going to begin synthesizing the antih antibodies so her second pregnancy if she again has an Rh negative fetus I'm sorry an RH positive fetus the Mom now has produced anti- antibodies that can go in and flag the baby's blood cells as being foreign so what do they have to do they treat it with something called rogam which is a serum that contains the anti um and can prevent an Rh negative mother from becoming sensitized to begin with so transfusion reactions so we get a transfusion reaction when the mismatched blood is infused um it typically is going to occur in which um um occurs in which the recipients uh plasma antibodies attack the donor's red blood cells so the donor cells are attacked by the recipient plasma a glutenins and it's going to cause a glutin or clumping and it can clog those small blood vessels if we have these clogs um in our small blood vessels they can cause the rupture in the release of hemoglobin into the bloodstream if we lose the hemoglobin that's in the red blood cells that's going to limit our ability to carry oxygen um it's also going to uh decrease blood flow beyond the block vessel so if we have a clot we can't you know Supply the tissues after that clot and um hemoglobin and the kidney toles can also lead to renal failure if you have some sort of transfusion reaction again if you receive the wrong blood type um your typical symptoms are things like fever chills low blood pressure and a rapid heart weight sometimes nausea and vomiting the treatment is really acting to help prevent kidney damage so Tak in a lot of fluids take some diuretics to help wash out the hemoglobin that has been liced out of these cells um again type O that's going to be a universal donor so they don't have any um A or B antigens a B's universal recipient meaning that their blood does not produce um the antibodies against antigen a or antigen B so blood typing so in order to type the blood basically the donor blood is going to be mixed with antibodies against common glutens if a glutenin is present or an antigen is present you're going to see gluten so you're going to see clumping so blood is going to be typed for ab and O as well as the Rh factor because those are the major causes of utenation um we also have cross matching which is typing specific donor with a specific recipient um mix recipient Serum with the donor red blood cells and mix recipients red blood cells with the donor serum so this is an example of blood being tested so we have type AB um blood basically put and assume two different Wells if this is blood type A here's antia right here we have blood type A so we would expect to see this clumping that's occurring um blood type AB with the antibody against B antigen would also cause a glutin or clumping because those antigens are present if we have blood type A that means we only have the a antigen so we would expect the um antibody against a to come in and attack it and cause clumping but we don't have the B antigen so the antibody can't attack um the blood there if we're talking about blood type B it's the opposite we do not have the a antigens so we wouldn't see clumping when we administered the um antibody against the a antigen but we would see clumping when the antibody against the B antigen was administered and blood type O um it doesn't have either antibody antigen on the surface of their red blood cells so we wouldn't expect to see any clumping regardless if we added the antibody for a or the antibody for B