How do blood transfusions work? – Bill Schutt


In 1881, doctor William Halsted
rushed to help his sister Minnie, who was hemorrhaging after childbirth. He quickly inserted
a needle into his arm, withdrew his own blood,
and transferred it to her. After a few uncertain minutes,
she began to recover. Halsted didn’t know
how lucky they’d gotten. His transfusion only worked
because he and his sister happened to have the same blood type— something that isn’t guaranteed,
even among close relatives. Blood types hadn’t been discovered
by Halsted’s time, though people had been experimenting
with transfusions for centuries— mostly unsuccessfully. In 1667, a French physician
named Jean-Baptiste Denis became the first to try the technique
on a human. Denis transfused sheep’s blood
into Antoine Mauroy, a man likely suffering from psychosis, in the hopes that it would reduce
his symptoms. Afterward, Mauroy was in good spirits. But after a second transfusion,
he developed a fever, severe pain in his lower back,
intense burning in his arm, and he urinated a thick, black liquid. Though nobody knew it at the time, these were the signs of a dangerous
immune response unfolding inside his body. This immune response starts 
with the production of proteins called antibodies, which distinguish the body’s
own cells from intruders. They do so by recognizing
the foreign proteins, or antigens, embedded in an intruder’s
cell membrane. Antibodies latch onto the antigens, signaling other immune cells to attack
and destroy the foreign cells. The destroyed cells are flushed
from the body in urine. In extreme cases,
the massive break down of cells causes clots in the bloodstream that
disrupt the flow of blood to vital organs, overload the kidneys,
and cause organ failure. Fortunately, Denis’s patient
survived the transfusion. But, after other cross-species
transfusions proved fatal, the procedure was outlawed across Europe, falling out of favor
for several centuries. It wasn’t until 1901
that Austrian physician Karl Landsteiner discovered blood types, the crucial step in the success
of human to human blood transfusions. He noticed that when different types
were mixed together, they formed clots. This happens when antibodies
latch on to cells with foreign antigens, causing blood cells to clump together. But if the donor cells are the same
blood type as the recipient’s cells, the donor cells won’t be flagged
for destruction, and won’t form clumps. By 1907, doctors were mixing together small amounts
of blood before transfusing it. If there were no clumps,
the types were a match. This enabled them
to save thousands of lives, laying the foundation
for modern transfusions. Up to this point, all transfusions
had occurred in real time, directly between two individuals. That’s because blood
begins to clot almost immediately after coming into contact with air— a defense mechanism to prevent
excessive blood loss after injury. In 1914, researchers discovered
that the chemical sodium citrate stopped blood coagulating by removing
the calcium necessary for clot formation. Citrated blood could be stored
for later use— the first step in making large scale
blood transfusions possible. In 1916, a pair of American scientists
found an even more effective anticoagulant called heparin, which works by
deactivating enzymes that enable clotting. We still use heparin today. At the same time, American and British researchers
developed portable machines that could transport donor blood
onto the battlefields of World War I. Combined with
the newly-discovered heparin, medics safely stored
and preserved liters of blood, wheeling it directly onto the battlefield
to transfuse wounded soldiers. After the war, this crude portable box
would become the inspiration for the modern-day blood bank,
a fixture of hospitals around the world.

100 thoughts on “How do blood transfusions work? – Bill Schutt”

  1. there is a mistake in the representation at 2:40 because he said same type but in the diagram there is A and B which are different types
    and thanks

  2. Ok ok, I’m watching this just because I saw some of those blood transfusion bags in the Octo Expansion but with sanitized ink, and it’s hecking disturbing

  3. Could you make a video about why some people like myself have such a hard time when it comes to blood. I felt uneasy just listening to the audio of this video. I recently did a bloodtest and got nauseous even though I did everything to calm myself down.

  4. Shoutout to all the amazing medical technologists/lab techs in hospitals doing the blood typing and determining antibodies! You don't get enough recognition and appreciation!

  5. Blood transfusion saved my life after I became anemic. I've never experienced anything like it before. I went from feeling exhausted and weak to feeling the life being pumped back into me. After that, I couldn't stop smiling. Since then, all I've wanted to do is find a way to donate to help someone else.

    I'm so grateful to the people who donate!

  6. “God views blood as representing life. (Leviticus 17:14) So we avoid taking blood not only in obedience to God but also out of respect for him as the Giver of life.”—Jw.org

    JW’s seem to be a bit culty here.

    Other hot topics to ask them about: their child abuse policies and extreme shunning of member who either officially leave or who are forced to leave because they do something horrible like celebrate Christmas. Funnest cult ever.

  7. I donated blood in November and learned I was o negative. My school has another Red Cross visit, but I cannot donate anymore for a year, because apparently I had low ferritin levels.

  8. I'm curious.. Are there any viewers, from a specific religious sect who forbids blood transfusion, watching this video?

  9. To think WWI is the inspiration behind the modern blood bank. Salvation behind the suffering is always overlooked

  10. And the poor horseshoe crab will go extinct soon. I grew up on the west coast of FL… I use to pick them up and play with them as a child. Nowadays you can’t see them in the wild! Harvesting their blood…

  11. When I needed a blood transfusion, the doctors had to get a really specific type of blood or else my body would flare up because of my Evans syndrome, and it took quite a while to find that blood….

  12. Blood transmission to save people life Thousands life save by blood It is help to living the human body 👍👍👍👍👍

  13. god, im still watching this. even tho i have a have fear of blood and needles.
    now my body wont stop tingling. ahaudha it feels asdfah fm n

  14. Hey You, a random person who is reding my comment,may your life be filled with joy and scented with flowers of wealth,health and good relations plucked from thw garden of humanity.Let your heart beat for goodness of everyone and you too pray the same for God, keeping in mind that we are very small part of universe but can do greater things.

  15. Transfusions done on dogs can be done the first time without typing- they will not have the immune response until the second infusion. This is incredibly useful for emergency vet med, because we can get blood from any healthy dog who may be in with us that day, and then immediately transfuse a trauma case. Just a fun fact!

  16. Is it wrong to think that, like all organisms, and all the knowledge we have about natural evolution, we (humans) would evolve and adapt to climate change? Or is it climate change happening too fast for us to adapt?

  17. Hello everyone. I want to take this opportunity to encourage all who are able to donate blood and platelets to donate. I recently beat Non-Hodgkin's Lymphoma, a blood cancer, and I received over 70 units of blood and platelets in the 11 months that I was battling cancer and blood banks constantly run low. Please take it from me that you don't really realize or understand how important donating blood or platelets is until you are dependent on donations made by people out of the kindness of their hearts. Blood donations are a huge reason that I am alive today. I encourage you to donate if you are able. Thank you and have a blessed day. 💚

  18. I recently donated blood earlier this year. It's a surreal experience getting a text from the company that drew your blood telling you that your blood is being used in a transfusion 🙂

  19. Blood is stored for up to 42 days but it starts to degrade badly at the 21 day mark the blood cells stiffen which is bad as they have to flex to get through capillaries it has been shown that people with enough blood volume that experience trauma and don't have a transfusion recover better. Look at this subject a little deeper and you will find blood transfusions are not the holy grail they once thought it was

  20. There is an error in 2:40, they say about how when both blood samples are the same type, it won't course blood clots, but the lustration show to beakers with different blood type

  21. Hmm, the constant changing of the background made me feel quite uneasy and distracted me from the content. Otherwise the video was a great and informative as always!

  22. 테드 이디 꿀잼(니네가 이 말을 알아듣긴 할까?트럼프 최악)ted-ed is funnnnnnnnnnnnnnn(i like it! 트럼프 이야기는 안함^^)

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