Questions tagged [hematology]

The study of blood, the blood-forming organs, along with blood diseases and their treatment.

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Why draw blood from veins rather than arteries?

Why draw blood from veins rather than arteries? Is it more convenient or safer?
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4answers
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Is there any advantage to one blood type over another?

All humans can be grouped into ABO and Rh+/- blood groups (at a minimum). Is there any advantage at all to one group or the other? This article hints that there are some pathogens that display a ...
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Can a person survive on blood in place of water?

This question: Can you get enough water by eating only fish? asks if a person could survive on fish alone. Can a person survive on fish and/ or blood alone of any species if stuck at sea or animal ...
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Why do mammalian red blood cells lack a nucleus?

How did the red blood cell in humans get to lose its nucleus (and other organelles)? Does the bone marrow just not put the nucleus in, or is it stripped out at some stage in the construction of the ...
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Can a cancerous cell from outside cause cancer in a healthy person?

If a cancerous cell enters the body of a healthy person from someone else's blood or something, will that healthy person get cancer? In human beings.
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Why do we need red blood cells?

From what I know, the main function of red blood cells (RBCs) is hemoglobin transport. So, why do we need cells packed with hemoglobin: why can't it travel freely in the bloodstream? My own thoughts ...
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Why do people have antibodies against other blood types?

The ABO blood type divides each blood type according to whether they have the "A" and "B" antigen(s) (AB has both, O has none). People also have antibodies against the antigens they don't have (AB has ...
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1answer
783 views

Are lymphocyte sizes clustered in two groups?

Tortora writes in Principles of Anatomy and Physiology: Lymphocytes may be as small as 6–9 μm in diameter or as large as 10–14 μm in diameter. Those ranges are quite close to each others. Should ...
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Do animals other than humans have different blood types?

Humans have the ABO and Rhesus blood typing systems. I have two questions about it: Why have we evolved these blood types? Do other animals have different blood types as well?
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Origin, or source, of rhesus negative in human blood

This is my first post here, so please be gentle. I recently learned that I have Rh- blood (I'm A-), and was idly looking into blood types on Wikipedia. I was surprised to find that relatively few (~15%...
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Is blood regarded as an organ?

It consist approximately 7 percent of body weight. By definition organ is composed of multiple tissues. Blood is a fluid, a circulating tissue. Therefore can we call this fluid system a liquid organ?...
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1answer
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Can you bleed from your bones?

I was talking to my science teacher about the body specifically the red bone marrow. She said that blood is created in the red bone marrow. Does that mean that if you were to cut a fresh bone open ...
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1answer
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Does a blood transfusion cure disease?

Does transferring blood between two people also transfer all the white blood cells? Why can't AIDS victims with low t-cell count just get blood transfusions till they have more t-cells? Why can't ...
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1answer
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Why does oxygen bind to hemoglobin in an specific angle?

There is an specific angle of the bond between oxygen and hemoglobin in lungs, which I don't know, but what interests me more is the question, why is it specific?
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Why isn’t Haemoglobin a plasma protein, rather than being encompassed by the erythrocyte?

Erythrocytes (red blood cells) are a common feature of almost all vertebrates. What evolutionary advantage do they provide in containing haemoglobin, rather than it being just a plasma protein? In ...
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2answers
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What magnification do I need to see blood cells?

If I want to buy a microscope for my kids to be able to view single celled creatures and blood cells, about what magnification is required? A Celestron Pentaview digital scope claims up to 600×. Is ...
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2answers
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Fate of erythrocytes after splenectomy

The spleen is considered a graveyard for red blood cells. So in case of Splenectomy (complete surgical removal of the spleen), what would be the fate of red blood cells? Would this cause Polycythemia?
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1answer
938 views

Where is the aneurysm in this picture?

I'm a curious person, I've never had any medical training, but I wish to know some more about aneurysms. Aneurysms are basically weakened spots in the elastic artery wall. This can eventually result ...
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2answers
435 views

Does the oxygen concentration equilibrate between red blood cells in the liver sinusoids?

In the sinusoids of the liver, venous blood from the hepatic portal system mixes with arterial blood from the hepatic arteries. Do oxygen molecules move between oxygenated RBCs and non-oxygenated ...
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1answer
276 views

Why do so many people have group O blood?

Please forgive me in case my question wouldn't make much sense. I was reading about ABO blood groups on Wikipedia, where I learnt that O is a recessive allele, and that it seems the A allele predates ...
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3answers
2k views

What is this microscopic image from Peter Gabriel's New Blood album cover?

This image appears on the cover of Peter Gabriel's album New Blood. It appears to be a photograph of some microscopic biological cell. But it doesn't look like a blood cell to me. What kind of ...
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2answers
25k views

What percent of your blood can you lose before you need a transfusion

Losing a little blood is okay. If your a normal healthy person, and got into an accident, how do they know if you need a transfusion or if you'll be okay? This is hypothetical.
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Can the mating of a couple with Rhesus positive and negative blood types result in miscarriage?

Can the combination of $+ve$ and $-ve$ blood groups of a couple be a cause of miscarriage in pregnancy?
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1answer
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What will happen if a foetus is Rh- and the mother is Rh+?

If a mother has Rh-negative blood and her foetus has Rh-positive blood it will result in rhesus incompatibility and lead to erythroblastosis fetalis. What will happen if the reverse occurs, when a ...
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Presence of MHC on red blood cells

Do red blood cells have no MHC? (I have often heard that they do not.) If so why are they not destroyed by immune cells?
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4answers
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Why do men have a higher hematocrit (red blood cell count) than women?

The hematocrit, also known as packed cell volume (PCV) or erythrocyte volume fraction (EVF), is the volume percentage (%) of red blood cells in blood. It is normally 45% for men and 40% for women. so,...
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1answer
235 views

What are the clotting factors' effect on avascular necrosis development?

Do clotting factors tpa and pai-1 lead to degenerative osteoarthritis in the same way that lupus anticoagulant and prothrombin might? Is one of these pathways particularly detrimental during formation ...
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1answer
451 views

Why does ammonium oxalate cause swelling of RBCs?

From Pre examination procedures in laboratory diagnosis by Walter Guder : ...It consists of three parts by weight of ammonium oxalate which causes swelling of erythrocytes balanced by two parts ...
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Why does the affinity of haemoglobin's for oxygen decrease at high altitudes?

My class 12 NCERT book says, Pg 226 The body compensates low oxygen availability by increasing red blood cell production, decreasing the binding affinity of haemoglobin and by increasing breathing ...
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1answer
71k views

How to translate a blood type used in Eastern Europe?

What are the I-IV blood type descriptions shown below (commonly used in Eastern Europe), and how do you translate them into the ABO-system?
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3answers
202 views

Why ml scale blood retrieval is required to run a blood test?

Substances found in blood are present at microscopic scale and tend to be invisible to the unaided eye. Why is a whole vial of blood (at ml scale) is required to assess the presence and concentration ...
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1answer
9k views

How does aspirin “thin” blood?

As we all know, aspirin doesn't actually thin the blood, as it has been explained to me, it makes it "slippery". Slippery blood doesn't stick to itself hence this helps prevent internal blood clots (...
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1answer
1k views

When giving blood, what is the specific Iron measurement they take?

I went to give blood the other day, and they take an "iron" measurement prior to actually drawing the blood. My level was 16.4 -- but what specific type of iron were they measuring? I've heard of ...
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1answer
657 views

Blood clumping in mosquitos

Will a mosquito die due to blood clumping if it sucks blood from two people who have different blood groups? What will happen in its gut? Is there any mechanism to avoid clumping? Or do mosquitoes ...
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2answers
5k views

Is there a purpose for nucleated red blood cells in reptile, avian and fish blood?

I have read, and read, and read documents on this subject but still have no conclusions. Everything I have read explains why mammals don't have a nucleus (to make more room for the haemoglobin and ...
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1answer
281 views

How does a glucose molecule enter the cell from blood vessel?

The transporters in the plasma membrane of the cells promote the entry of glucose molecules from the extracellular matrix to the cytosol of the cell. Could someone explain how does the nutrient ...
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1answer
12k views

Why extract DNA from certain white blood cells instead of whole blood?

In my lab, human DNA is extracted from whole-blood samples. I don't actually do the extractions and I am not familiar with the specific protocol but I understand that platelets and red blood cells ...
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2answers
495 views

What's the smallest animal with hemoglobin running in its veins?

What's the smallest known animal with hemoglobin running in its veins? Here I mean an animal that on its own is able to produce the hemoglobin that is running in its veins. For that reason this ...
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2answers
5k views

Why do people with type O blood have anti-A and anti-B antibodies?

People with type O blood have anti-A and anti-B antibodies, even without receiving a transfusion. Why?
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3answers
9k views

Why do red blood cells maintain Iron in the Haem group in the +2 (ferrous) oxidation state?

A lot of sources tell me that RBCs contain a number of enzymes, and that these serve multiple functions from maintaining the structure and elasticity of the corpuscle wall, to preventing the oxidation ...
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1answer
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Why are red blood cells considered to be cells?

Wikipedia states that a cell is the basic structural, functional and biological unit of all known living organisms. Cells are the smallest unit of life that can replicate independently. It then ...
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1answer
932 views

Parents are Rh +ve and child Rh -ve

Suppose the two parents of a child have blood groups A+ve and O+ve, and the child has O-ve type. For blood group, there are two alleles. Since the child has O, the father must have one 'A' allele and ...
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2answers
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What happens when you mix type A with type B blood (and v.v)

What happens when you mix different blood types that are not compatible? For example, if a patient has type A blood and receives type B blood, or v.v.?
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2answers
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How does Bernoulli’s Principle apply to the cardiovascular system?

Below are graphs which illustrate the cross-sectional area, velocity, and fluid pressure through each vascular segment of the cardiovascular system. It makes sense that velocity and cross-sectional ...
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1answer
117 views

Blood cells penetration

Is there a type of blood cell that can reach all other body cells? By "reach", I mean to "touch" the surface of the target cell. If we look at the red blood cell for example, that moves in blood ...
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1answer
195 views

How can a child be blood type AB, if both of the parents are blood type A?

Basically, both of my parents are blood type A (both are confirmed and it's also certain both of them are my biological parents). I recently found out my blood type is AB. How is this possible? I ...
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1answer
1k views

Hemoglobin oxygen affinity curve

I have a general understanding of the Bohr effect, and that Hemoglobin's affinity for oxygen will shift depending on the conditions of the lungs and tissues. However, I'm struggling with the following ...
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1answer
12k views

Time lapse between fresh blood's exposure to air and that same blood turning darker red-brown

For investigative purposes, I'm searching for a tool that can be used as a quick visual assessment of the the length of time that blood has been exposed to air after the blood flow has stopped.. Let's ...
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0answers
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Found in blood sample - what is it? Hopefully not a nemotode-

After examining someone's blood - through microscope - I found these. There were some more that were not photographed. Could someone please inform me on what these are? Maybe abiotic material on the ...
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1answer
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Why does blood come from mouth when people are shot in the chest area?

In almost every movie scene when a character is shot in the chest area, some blood comes from his mouth or sometimes even coughs blood before he dies. Are these kind of scenes realistic/possible? If ...