second part of chapter 19 starts with hemostasis which is the process of a body trying to stop some sort of bleeding um bleeding comes in all kinds of forms it can be a small cut and it can be obviously a huge cut where you're um losing large amounts of of blood from your body this can be internal as well as external again so we have to keep that internal portion um in in the in the back of our minds because we tend to think about what we can see and what we cannot see so the process of stopping bleeding or we call the cessation of bleeding uh there's three things we'll look at vascular spasm platelet plug formation and coagulation we'll start with vascular spasm just two things to know they're basic um immediate kind of reactions that can occur usually with very small damage it happens daily all the time inside of our body nothing nothing that would recognize or know that was happening but a vascular spasm is just the ability of a blood vessel to constrict um because of the little bit of musculature that's found in all of them or the blood vessel lining sometimes it doesn't have muscle muscles involved but some sort of um cells that can constrict to some extent so two things you need to know is endothelin which is produced by the endothelial cells that are found inside all of the vessels it's that layer of cells on the inside or the only layer um which leads to the constriction of blood vessels and then they also have um something called thromboxanes that are produced during platelet plug formation which is coming up next um and these also the thromboxanes also lead to the constriction of blood vessels and not to the point where nothing's flowing through but enough to decrease the flow of blood so plet plug formation is a way that we can seal small breaks in blood vessels so whether it's a cut or whether it's a tiny damage a hole that is a result of damage um to the body or to the vessel um the platelet plug can stop some sort of uh leaking of blood so this is not a blood clot it's going to be a little different than a blood clot formation but it's sort of the precursor to it um three steps here are listed for you uh obviously there's a little bit more involved and most of this is all taking place at one time but it I can do it in steps so it makes a little bit more sense so the first part is platelet adhesion which is going to be when the platelets start to bind to the exposed collagen from the blood vessel and this adhesion is um helped with the process the process is helped by something called the vanon willbrand factor which is a protein receptor um that is on the the the surface of the collagen that's being exposed um from the damaged vessel and you'll see that in the picture below um after the P let at here here to the collagen they are activated and then this helps other platelets to become activated as well so it's sort of like one platelet tells another platelet tells another platelet and they keep kind of all coming into that given area and sticking around and trying to form this platelet plug as they become activated um uh they will start to change shape that you'll see in the picture they're going to flatten out a little bit and they're going to start producing something called fibrinogen um uh or they're produce these fibrinogen receptors that allows uh a plasma Pro to that's present in the plasma called fibrinogen which we mentioned in earlier section that's going to start to bind there as well and that's going to help form that platelet plug so just going to go over to my whiteboard here so I can show you a little bit on this image for you it's right here so in this image at top here you're going to see uh the platelets are the initial cells that are formed right here at the top they're just in the blood vessel floating by with the rest of the blood that's passing by you have the damage that has occurred right here so this is the damage in the blood vessel you have the collagen that's exposed and then you have these little black lines here that's the van Willa brand Factor they're The receptors that are there they allow the platelet to not only change shape but to also stick there so they're happening everywhere over here as well so we have them flattening out and binding two of The receptors the thromboxane is going to be released um there's going to be some adenosine diphosphate that's involved with that don't really care too much about it but those are going to call in other platelets that are going to come into here and they're going to start as you see in the next picture coming into place and as they come into place they start producing fibrinogen which is going to be the bridge that holds all of these platelets together sort of like they're all holding hands and therefore they can come in together and they can form this platelet plug that going to result and then the thing and everything that comes after that will happen next so there's the picture just wanted to show it to you and then um vascular spasms and PLP plugs um may not be sufficient alone sometimes it a vascular spasm will work and it can heal itself quickly sometimes it's the vascular SP spasm and then the platelet plug um but then for larger tears um or something that's a little Bor more extensive I'm not talking about something that need surgery it still can be large enough that your body can take care of it but it's not something necessarily that we can actually see happening um necessar internally you might see it externally over a period of time but when blood vessels are severely damaged uh we need something called coagulation to occur or blood clotting this is going to result in the formation of a clot we refer to it as a blood clot and it's basically just lots and lots and lots of proteins all threaded in embedded together and crisscrossed um together they trap all kinds of things within it so you're going to have blood cells platelets fluid dead material uh bacteria depending on where the cut is all kinds of things are going to get trapped into this blood clot um the fibrin of course is going to be the main component of this so blood clot formation is going to depend on many different things the chart below is going to go over lots and lots of what we call clotting factors or coagulation factors it doesn't matter they're all proteins they're all genetically predetermined so this is where if you're missing one of these this is where hemophiliacs would come into play um with the ability to not uh stop bleeding in some cases so the whole list is here I'm not going to go over all of them we don't need to know all of them but the first three fibrinogen prothombin and thromboplastin um those uh will mention we've already mentioned fibrinogen and sort of mentioned Pro thrombin but not really but um those are the three that you might hear but there's plenty more they're all by Roman numerals so there's lots and lots of them all that you can see down here that they've discovered and then they also have some platelet factors in here and you can see what they do as well so clotting factors are activated in two ways um these can happen what we call intrinsically or extrinsically not going to get too complicated here but we're all going to start out with that damage so the damage is going to start I'm going to go over to the Whiteboard just so I can show you this picture and we can go down the steps so we can look at it together over here so the same idea is going to happen you still have this blood vessel here um that has some sort of damage here so the platelet plug has form so first of all we have that platelet plug so there's extrinsic and intrinsic so extrinsic is going to be some sort of tissue damage is going to cause a whole Cascade now you do not have to know all these cascading effects that are going to happen but there's um they're all going to converge or convene at one point in time in some place so there can either be tissue damage um so that's going to be stimulated by something called thromboplastin and also that factor 7even that's there again not going to ask you these Factor sevens um and just because it gets too complicated um the intrinsic p pathway occurs when there's contact with collagen so that is the big difference between them so it's either just some sort of tissue damage and they both can happen um or whatever but either way they're going to cause this cascading of effects and you're eventually going to get to something called Factor 10 and activation of both extrinsic or the intrinsic pathway is always going to result in that factor 10 being produced and then that's going to be where our prothrombinase actually converts prothombin into thren and and then the fibrin is produced and we have a fibrin clot at the end and again I'm not asking you for all of those um it's I'm not going to ask you for the sequence of events just wanting you to know that there's lots of different ways that a clot can form so again extrinsically versus intrinsically we have all these factors involved but the main thing is we need to get this activated Factor 10 once that can happen we can get the fibrin clot to form if for some reason genetically you don't have this or any of these things in here you're going to have a big problem because you can't get from one step to the next without all these factors so it is very important that we have um these factors being produced and again it's a genetic thing that we have here you also see a arrows going backwards in this image so just showing that they can go back and feed other things to happen and increase so that whole feedback mechanism can happen as well um within this whole process so just wanted to to go over that with you I'm not necessarily going to ask you for every single step in the process uh that's not the idea here so just know that there's extrinsic and intrinsic Pathways um and they can lead to that whole uh clot formation uh the clinical important of importance of a a aspirin if you need to look at that you can um if you know anyone who's taking that they're now actually not even recommending that people take that every day they've sort of gone away from that um here's a recap of the extrinsic pathway with its definition the intrinsic pathway obviously because it's it's internal to the blood vessel where the collagen is and then it goes over the pathways for you um if you want to check that out one other thing just to mention here that's probably important vitamin K uh we get it from our diet and we also get it from the bacteria that are living in our intestines they actually produce it for us that also is actually important for the formation of those factors in the blood clotting so all those Roman numerals factors one factor 10 Vitamin K is actually needed for that so um that's important to know because we need Vitamin K although um we don't necessarily always get it from our diet we actually get it from the organisms living with inside of us so control of cop formation um for some people uh have an a tendency to form clots more so than other people and this is where um people would have to take maybe um anti-coagulants or we call them blood thinning drugs um there's all kinds of different names we'll talk about warrin or inumin if you've ever heard of those names um sometimes you can get sick um a bacterial infection can cause problem and you take anti-coagulants lots of different reasons why blood clots can form it's not just because you know platelets are activated um but there's obviously things that can cause that so to prevent any kind of unwanted clotting um we do have anti-coagulant that can help um help prevent those factors um all those Roman numeral factors from getting stimulated um but there's also other ways so coagulant in the blood we have obviously if you remember from the picture we have thrombin which is important for making the fibin so therefore we have things called anti-thrombin as well Heparin we've mentioned before Heparin is important um as an anti-coagulant as well it's produced if I if you remember when I talked about basophils basophils produce that Heparin to help reduce the likelihood of a clot forming and then we have something called uh prostacyclin um which are uh they're also produced by end thelial cells and they actually will work against the effects of thrombin and actually cause vasodilation instead of Vaso constriction so there are ways of interacting with all our body can interact with not only U molecules that can help with the clotting we have anti-clotting ones as well so it's important um you know for our body to have these abilities because we never know how one person's going to react to something else so there are other things besides heprin that are used as anti-coagulants or's something called Eda that you may have heard of and um that's used to prevent clock formation as well Eda can be found in actually vaccines as well um so for those of you learning about the covid vaccine because that is so new um that actually has EDTA in it because the the mechanism by which the vaccine is made can cause clotting so they actually add something to prevent that but um that's a different time and a different story um so clot raction and dissolution eventually blood clots do have to disappear like so if you're thinking about the scab on your a cup on your skin that fibon um nesw work um eventually does have to be um you know removed it has to go away but what has to happen first is that that that seal has to be closed so that or seal that the opening in the vessel has to be closed so once the clot is formed we then have something that's called clot retraction and that's where um the contractile proteins of actinomyosin will actually um come into play because um the platelets have the ability to do that and they can contract and pull the vessels or the the cells closer together so we can close that vessel uh which is really important um the clot retraction pulls the edges of the vessels together again stopping the leaking stopping the blood flow um reducing the possible chance of infection because everything gets caught in that fiber mesh work and then obviously we have to worry about uh the clot dissolution which will happen next and that's the removal of um all the fibrin and breaking down all the fibin so so the clock goes away because now it's been healed um and there's no more leaking going on so there's a little part down here um so there's um things that can be done to reduce clots um so understanding exactly how this plasmine works and breaks down the fibrin that's also very useful for people who have had heart attacks or Strokes um you can actually inject them with certain kinds of enzymes or proteins that can help to uh break up clots so that um someone doesn't have more damage done in their heart or their brain so it's something called tissue plasminogen activator TPA um if you've known anyone who's uh maybe had a clot or had a stroke or had a certain type of heart attack they actually can get that um injected into them pretty quickly but there is a timeline for using drugs like this it's not like you can wait a few days and then decide you only have like a couple hours I think I think it's like 12 to 24 hours um and then that's it you can't use it after that so the danger of unwanted clots just talks about warin uh which is uh also known like there's also something called Kadin it's they they're the same thing it's just the names that they give them but they act very similarly to Hein and stop in as um clots from forming um but just act a little bit more slowly you do have to be careful because um they are um impacted by vitamin K and you know you can actually become uh you can actually bleed like excessively bleed um when you cut yourself internally externally whatever if you're on uh warrin or kumin um and you have too much vitamin K in your body can actually make it worse so sometimes you have to actually restrict your diet with that one as well okay so blood grouping a little bit about blood grouping and transfusions and um you know infusions that are going to be uh involved in a lot of Hospital work you need to understand the um the idea of what's going on between um the different types of blood groups so I have it highlighted here um basic go over some basic information I'll go over to the Whiteboard for and go over all the blood groups that we're going to talk about in this picture that you need to know and then we'll move on to some further information um with all of this so you know why you can't mix blood types or which blood types can have um you know which ones can be mixed together which ones cannot be mixed together so I just going to want to go over some basic information here that you may or may not know but obviously um the red thing here is a red blood cell um it has that dis shape on the outside we have these little orange um markers they're called antigens they are proteins uh that stick off the surface of the red blood cell and they can be all different sizes and shapes so a antigens have these circular proteins on the outside or circular antigens on the outside B has these pointed ones AB blood type is going to have one of each or a bunch of each of them and then O blood type which is out here the types are at the bottom has no markers or no antigens we sometimes call them naked they don't have any kind of proteins on the outside of them so with blood typing what's important to know is that we are already pre-made when we are born with certain red blood cells which have certain markers or ID tags on the outside of them and then in our plasma we have globins which are antibodies already floating in our plasma we're genetically made to have them now our antibodies will not match up with our antigens cuz if they did our antibodies would stick to the antigen and we'd start clotting and then we would die which is not a good thing so we are born with the antibody that's opposite the blood type that we have so a blood type has anti-b antibodies so they have antibodies that are anti-b or against B blood type the B blood type has these triangular shape antigens but they have cup-shaped antibodies so they have antibodies against a so anti means against so they have antibodies against a so therefore you know we can't mix these two together absolutely not because immediately your blood's going to start clotting because the antibody is going to fit directly with that antigen and it's going to do it to every single your every single one of your red blood cells and they're going to start all your red blood cells are going to start sticking together which is not a good thing and you can't mix B uh a with B either so you can see how they match together so those are pretty simple because they're the Opposites of each other when we look at AB blood type AB blood type has nothing in the way of antibodies it can't we can't have these antibodies in here because they're going to match with those and we can't have those because they'll match in there too so we can't have those so an anti um blood type AB doesn't have either um antib body in their blood plasma O blood type has nothing on its outside so therefore it has both antibodies floating in its bloodstream so what that means is when you talk about blood group if you are type A you can receive a blood type that's good and you can also receive a blood type that your antibodies can attach to so if we look at a and what a has these can attach to those let me just erase some of this these can attach to this one and this one so we can't give it B and we can't give it AB but we could give it to we could get O blood type because they don't have anything on the outside so if you're a blood type you can receive a or o if you are B blood type you obviously can receive B and the same thing you can receive o if you are a b blood type you can receive anybody's blood type AB or sorry AB can receive AB you can receive B blood cells a blood cells and O blood cells and in some cases they do separate out and they don't give you the antibodies it's packed red blood cells versus plasma but if you are AB because you have no antibodies you have nothing there to fight you can receive any blood type so you are called the univers unversal recip recipient you can receive any if your O blood type you can only receive O blood type because you have the cups and the v's so you will automatically start fighting everybody so you can only receive o however because O blood typee has nothing on its surface you can give it to AB you can give it to A or B and you can give it to a so you were considered the universal donor because you have nothing to attach to on the outside there's no no markers out here you have no markers on the outside so therefore there's nothing you have to worry about attaching these antibodies can't attach to it they can't get it so that's where the blood grouping comes in so now we'll go back just a little bit more here there's also the idea that we have um Rh factor which is the recess Factor so you can watch the video here for if you would like you can take a look at the um the little animation they have here the picture they have here but the idea of what I just said on the other side is all here in blue for you if you need to to read through it the other part is the RH blood group um that was it's called RH cuz they found it originally in rees's monkeys and we call this the D antigen and this is just another marker that can be found on the outside of blood cells and in the case of being positive or negative it's just another another protein and you either have it or you don't so on the outside of this red blood cell you would have um let's just put a t out there that would be RH positive so if you have this thing this thing just makes you positive so You' be a positive if you don't have it like let's just say we're looking at this one if there is no black T hanging out here then you would just be B negative okay so you either have another protein or you don't but if you have it your body knows what it is it won't fight it but if you don't have it like B if you've never seen it before and all of a sudden I start putting a bunch of teas in your bloodstream or a bunch of blood with a tea on it you are going to have an immune reaction your body's going to say I've never seen this before and because I've never seen it I'm going to start making new antibodies to it may take a little bit but I'm going to make antibodies to it I'm going to fight it then we're going to start having clotting and then we're going to have a problem so it's not a good thing so when we talk about blood grouping positive can receive positive and negative blood if you are negative you can only receive negative so that is something to keep in mind with blood typing if you're positive you can receive positive and negative blood if you're negative you can only ever receive negative blood so that's uh one more important point for this the problem with this comes into something called um they they call it a hemolytic syndrome it's a disease of the newborn and this is where the idea of um an Rh negative mother and um having a different blood type and the baby comes in it only works in one way and it only works with females who are pregnant and they are negative blood type it does not you have nothing to worry about remember if you have positive blood your body doesn't care if you get positive blood or you get negative blood because you know what the protein looks like the problem is when the mother is negative so the mother is negative blood type and she's never ever ever seen positive blood so when the mother during the first pregnancy and this is how it has to work with during the first pregnancy if the mother's blood the maternal blood is negative but the baby's blood is positive if at any point in time during I don't know if I can draw on this so let me just take a little shot of this real quick and then we'll go over to the Whiteboard so when the mother is negative blood type she's negative the baby is positive when the baby's blood happens to mix during birth or during somehow maybe the placenta something happens you now have positive blood in a body that's never seen positive blood before so the mother is going to start making anti RH antibodies or antibodies against the RH that's now in her bloodstream so she's going to start targeting all this and she's going to have these anti antibodies in her blood forever so the first pregnancy is going to be just fine because usually the blood mixing happens during delivery so the first pregnancy is fine first is usually successful it's the second pregnancy and any pregnancy potentially after there that the problem occurs because now the maternal blood already has those anti RH antibodies in there they're already there so the mother circulation already has it so if RH positive red blood cells cross the placenta and enter the maternal circulation they will cause those antibody production to happen rapidly because she's already seen them and you'll start producing even more of them and then the antibodies will cross the placenta and it will actually start clotting and causing hemolysis of the newborn or the fetal red blood cells they are going to start being liced or bursting and then the baby is going to die in utero um it'll be born still born around 5 months to 6 months of age uh uter fetal fetal development age um and that would be it so to prevent this and to stop all of this um because it it now can be prevented so if you are a negative blood type so if the mom is negative and the baby is negative we're all good but if the mom is negative and and the fetus is positive that's bad so we need to take something called the rogam shot the rogam shot is an injection that they can give you multiple times throughout your pregnancy but what the rogam shot does is it prevents you from ever making antibodies especially if you're if you become exposed to them you actually don't have to worry about it I spelled it wrong but the rogam shot is here for you it actually prevents you from making antibodies because it'll destroy the fetal red blood cells um before they can even enter the mother's bloodstream and cause a reaction so you can have multiple pregnancies um without ever having to worry about that so that's in that last paragraph for you okay so diagnostic blood test so blood typing if you hear somebody saying uh like on TV shows that there a type and a Cross Match needs to be done or whatever they say um this is basically to prevent any kind of reaction that occurs during a transfusion so obviously we know our blood type but they're still going to make sure of your blood type before they start infusing you with some other or transfusing some other blood type into you um but it's going to go off your normal blood typing and R the Rh factor whether you're positive or negative um but there are some genetic conditions out there that they do have to pay attention to that your blood type might not actually be what it says it is um but patients blood cells will uen if we mix the wrong ones together so we say gluten we mean clot or Clump together so we have to make sure that um we're not mixing anything that's not compatible with each other and they do that very quickly um you can do it very quickly with blood typing on a slide by just mixing blood with certain solutions that we have um just to make sure no no clotting is going to happen um in a cross match the donor's blood cells are mixed with the recipient's serum um that's because um we want to make sure that there's no reaction with the plasma that's going on that's going to be mixing as well the donor serum will also be mixed with the recipient cell um the donor's blood is only considered safe if no uation happens in both so it has to go in both directions because as I said there are some other things that could be going on and this these are all genetic things um that can happen that your blood type isn't necessarily what it seems to be a complete blood count that is an analysis of someone's blood profile if you have something called a CBC that just means a complete blood count so they're going to do your red blood cells your white blood cells um they're going to do a differential white blood count which means they're going to tell you how many eosinophils you have how many neutrals you have how many BOS basophils you have so they do all of that they also do your your hemoglobin and your hematocrite so they can see um you know absolutely how much red blood cells are present um and in your plasma so that's important to know as well um especially because it can tell you whether or not someone's bleeding internally that you may not know about so again we have to know those numbers those normal numbers that we should have the rest of this chart just goes over some different types of conditions maybe some that you are familiar with anemia meaning iron deficiency Is Us one people are familiar with um people may have be folate deficiency anemia which is really important um for uh cells when they need to go through mitosis and that could happen if you're on chemotherapy you don't have enough folic acid in your diet so lots of different things aplastic anemia phemia and then probably the more common ones leukemia most people know about but that's a cancer of your red bone marrow so you produce lots and lots of white blood cells but those white blood cells uh don't function correctly so it's not like it's better for you um we have clotting disorders and the Von V willbrand disease would be um an inherited disease and now that we know about the platelet plug this one make make might make a little bit more sense to you hemophilia again another genetic disorder where you can't clot your blood it can be due to lots of different of clotting factors um it's most oftenly sex link so men men tend to have hemophilia more than than females do and then there's infections of the blood that can disrupt our um production of red blood cells uh malaria being one of them which is a protest infection after a mosquito bite which can cause um the destruction of red blood cells which obviously can be very harmful acquired immune deficiency syndrome is a viral infection that uh destroys our white blood cells especially our T lymphocytes so therefore you have um you know a very very um suppressed immune system because you don't have certain types of white blood cells to F to fight infection um hemoglobin measurement just a little bit here at the end here so you know why your hemoglobin as I mentioned before um just above hemoglobin measurement just determines the amount of hemoglobin in a given volume of blood so this one will be per 100 Ms of blood and it gives you a normal range for males and for females that always has to be taken into account and this is to see whether or not you have um some sort of anemia the hematocrit is the total volume the total blood volume that's made up of red blood cells so there's a little machine here you can they're called capillary tubes you just need a little bit of blood it sucks up into the hematocrite tube it just kind of sucks it up in there and then it separates it out for you we can centrifuge it very quickly and again you're going to get that plasma The Buffy coat and you're going to get sort of what we started this chapter with the amount of um conc concentrated red blood cells and they can tell you you know what the percentage is and again the amount of red blood cells compared to plasma can be very important um so it it can tell you lots of things that could be going on inside of a person's body so the size of red blood cells can affect that obviously if you have a lot of small red blood cells you could actually have more red blood cells just that they're smaller if they're larger you could have less than them so they actually can measure all and that all comes into play with how much oxygen you're carrying and how much red blood cells are actually in your plasma um so you know lots of different things can happen but you can read this and and you know um you can see what the difference is between your normocytes your micro sites um and your macro sites which are just obviously sizes of the red blood cells um and that obviously can affect how well you carry oxygen your white blood cell cell count there are two things lucenia and lucos that can happen in leukemia which we already mentioned but lucenia is just a lower than normal white blood Cal sound and they it could be due to a lot of things but this one is just something's going on with your red bone marrow but obviously viral infections chemotherapy radiation um vitamin deficiencies can all play a role in that as well here's your differential blood count that I mentioned before it just goes over all the different types of white blood cells and what the percentages are of each of those and then they can you know sometimes determine what kind of infection or what's going on with someone just by the amount of um U white blood cells that are present and then the clotting issues we have our platelet count they can determine obviously we have that range that we like to talk about it's a very big range per microl ler of blood or drop of blood um but when there's um a a reduced count we call it thrombocytopenia and again there can be lots of reasons why that is happening and you can take a look at that if you're interested uh proin Pro prothombin time measurement um expresses how long it takes for um the blood to start clotting so um you can actually see that and you can measure that and that can help determine if you're missing um certain uh blood factors um or if you have um a vitamin K deficiency um and that could be due to pharmaceutical drug therapy or it can be do for lots of reasons but that's one thing that they can take a look at so blood chemistry is really important because um that can tell you all the dissolved and suspended stuff in plasma and again tons of different things can be wrong with somebody so when they do a whole blood blood work up on somebody they're trying to pinpoint something but everything can come back in normal range and then that makes it even more difficult to figure out what's wrong with some someone and that's usually even more frustrating than anything so at the end of each chapter we have a great little summary here again I have the highlights for you they're in a PDF file you can download them and write on them while you're listening to the recordings but also don't forget to check out the end of the chapter which is a nice summary and it sort of puts everything together in bullet points for you and then there's questions but I obviously have stuff for you on um Blackboard as well