I just went for a blood test and came back knowing I have type AB blood. However my blood can only be used by other people who share the same blood type with me but not others, while other people with type O, A, B they can share the blood with me. Why is that so?
In: Chemistry
Platelets are like puzzle pieces. Think of it like some puzzle pieces only have inverted dents, some only have protruding notches, some have a mixture of both, and some are the rare puzzle corner or side pieces. You need a blood type where the puzzle pieces (platelets) won’t fit together, but glide away from one another so that they don’t clot. That’s my best simple terms explanation. Hope that helps.
Mate different blood types exist due to variations in antigens on red blood cells. Type AB has both A and B antigens, so it can receive A, B, AB, or O blood
Your immune system’s way of recognizing “friend vs foe” boils down to basically “known vs unknown”. Your white blood cells generally don’t react to chemicals that they know (because they are supposed to be your body), but react to chemicals they never encountered (because they are likely to be a pathogen). We use the word “antigen” to mean “something that causes immune reaction”.
There is some variation in the way some chemicals in your red blood cells are made. As far as we know, they serve no evolutionary purpose, but there was also never any evolutionary pressure to remove thise variation. The “antigen A” and “antigen B” are just names for chemicals that some people have on their blood cells, and some people don’t. Your cells have both, so if you share your blood with a person that doesn’t have one of them, their immune system will recognize them as a threat and will destroy your blood cells. However if yout get blood from them, there will be no problem, as your immune system will be OK whethere these antigens are there or not. This makes you an universal recipient, while people with type-0 (neither antigen present) are universal donors.
Imagine that your body is a big sports stadium full of passionate fans. Let’s say that the home team’s colors are blue and red, and the opposing team’s colors are green and purple.
If a visitor wears a blue shirt, a red shirt, or a blue-and-red striped shirt, they will fit in perfectly with the fans, so they will be welcomed into the home team section of the stadium.
A visitor could also wear a plain white shirt with no colors at all. The fans would not consider this to be a threat, so this visitor would also be welcomed.
Now, let’s say some fans of the opposing team visit. They would be wearing shirts that are green, or purple, or green-and-purple striped. If the home fans see ANY of those colors, they will boo and harass the visitors! They want these enemies out of their section! Eventually the green and purple fans will have to leave because they are getting attacked.
Blood types are determined by antigens. Antigens are little outfits that your blood cells wear. They are team colors for your body. The possible colors are A, B, and + (O means neither A nor B, and “-“ means the absence of “+”). Someone with AB+ blood has the “colors” A, B, and +. Their home team uses all the possible colors. So visiting cells that have any combination of those “colors”, or even visiting cells with no “colors” at all, will be welcome. Some people describe AB+ blood type as the “universal recipient”, because they can accept any blood type since they recognize all the possible colors.
Someone with A+ blood has two colors, A and +. Visitor cells can wear A and/ or +, or they can wear no colors at all, and they will be welcomed.
Someone with O- blood has no team colors. If a visiting cell is wearing ANY of the colors, they will be rejected as an enemy. This patient can only accept cells that also are wearing no colors. Some people describe O- blood as the “universal donor.” These blood cells aren’t wearing any team colors, so they can freely visit any stadium without being attacked.
While we all have blood, some peoples bodies make it with a *slightly* different mix. When talking about blood types, the most important distinction is some identification markers that sit on the outside of your red blood cells, kind of like name tags. The ones we’re interested in are called Antigen A, Antigen B, and the Rh factor (positive or negative). There is no Antigen O, it just means you don’t have A or B.
Why it’s important is that your body looks at the name tags of blood cells to see who’s supposed to be in the bloodstream and who’s not, kind of like a bouncer checking IDs at the club. If the bouncer finds people with the wrong name tags, it thinks the body is being invaded and starts a fight. If you got a blood donation, it would obviously be bad for your body to start destroying the new cells; you can become sick, and it might make your original problem come back or get worse.
So why are some blood types compatible and others not? Your body will only accept blood cells with the tags that it thinks belong there. The bouncer (your immune system) is only looking out to fight cells with tags that it knows don’t belong. Since you have AB, your body thinks any cells with tags A, or B, or both, are cool. If you had type B, your bouncer thinks Bs are cool, but As are not allowed so the fight is on. O is a special case because O has no tags. An O bouncer will only let in cells with no tags; if it sees A or B or both, the fight is on. But A or B bouncers don’t see any tags on an O cell, so they don’t start a fight. That’s why everyone can get O blood (no tags), but O people can’t get A or B blood. Rh is the same, but separate. If your body is Rh positive (you have it on your cells), you can take positive or negative blood, but if you’re negative, you can only take negative blood.
This is all a slightly complicated way of saying some peoples blood has different ID tags on it, and your body will fight any tags that it doesn’t like, but ignores cells without tags. AB type is alright because your body thinks all the other blood types are cool.
We have proteins on our red blood cells. You have A protein and B protein = blood type AB. If you get blood from someone with A protein on their blood cells, your body recognises that and accepts it. Same with B. Blood type 0 means neither A or B protein. The body is fine with that too
If a person with blood type A is injected with blood type B, their body won’t recognise that protein and will destroy those blood cells. The destroyed cells will cause all sorts of complications in the body and the person can die if there’s a lot of them. The cause of death is usually kidney malfunction because the kidneys are trying to filter out the destroyed blood cells but there’s too much, or shock which is when several organs don’t get enough oxygen (the red blood cells carry oxygen to the organs) and they can’t function and it becomes a domino effect and the whole system collapses
No one really knows why different blood types evolved. It was probably a random occurance, the first person with the new blood type didn’t die and it spread. Blood types are not evenly distributed, some ethnic groups all had the same blood type before people started travelling. Native americans were almost all blood type 0. Blood type B is more common in Asia than Europe, and so on https://en.wikipedia.org/wiki/Blood_type_distribution_by_country. Some blood types offer immunity to some diseases and that’s how they survived. Others are just genetic hiccups.
The ABO-system for blood types is the most common, but there are others. Some are rare but you do come across thrm from time to time, Like Kell and Duffy-systems. Others are so rare they only exist in one family
While many comments are explaining the ABO and Rhesus system, none are explaining why we EVOLVED to have those. The answer is: we’re not sure.
In terms of morphology, we know that the Rh antigens are membrane transport proteins (proteins that help move ” things” in and out of the cell’s membrane). Some think that they are parts of a ammonia transporter, but it’s not clear.
Why do we focus on this particular group of antigens to denominate blood “groups”? Because they are the main cause of the immunological reactions that arise when you transfuse “incompatible” blood (hemolysis and diffuse intravascular coagulation). There are many other antigens on blood cells, that we can study but are less relevant, because they cause less incompatibility reactions.
It’s not exactly what you asked for, but the context is interesting imho.
While your red cells Rent useful go anyone but AB. Your plasma is highly desirable. It’s rhe equivalent of O NEG blood in an emergency situation. Your plasma has neither A, B or A,B antibody and can be taken by every blood type.
Amd while you can recieve every type of red cell, you can ONLY recieve type AB plasma.
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