Questions tagged [blood]

For questions about blood, its use in the circulatory system, its effect and what would happen if it was changed.

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A creature has one heart per bodily extremity. How large does each have to be?

The creature has several hearts, each supplying blood to one limb. For all other intents and purposes the creature is human. Of the six smaller hearts, one supplies each arm and leg, one supplies the ...
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2 votes
2 answers
560 views

My creature mixes lye and sal ammoniac to cool its blood. How cold can its blood get before it stops working as blood?

Background information: According to various sources, the human heart pumps 5 liters of blood/minute at rest and 15-20 liters of blood/minute during running or exercise, 6,000 to 7,500 liters of ...
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7 votes
2 answers
705 views

Could interspecies blood transfusion from organisms of various sizes occur?

In my universe, there are sixteen species from the Homo genus: anatomically modern humans, demons, angels, merfolk, ogres, giants, halflings, dwarves, elves, goblins, gnomes, orcs, trolls, vampires, ...
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1 vote
0 answers
82 views

What would it be like to have your hand chopped off by an axe? [closed]

A child character in my book was caught stealing food for their parents and the people who caught them chop off their right hand with an axe as a lesson to "keep their dirty hands off". I've ...
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-2 votes
2 answers
179 views

Would a vampire be able to use a blood substitute as a food source, such as coconut water? [duplicate]

I have a character in my story who is both a vampire and a practicing Muslim. I have another who is also a vampire and she subsists off menstrual blood. [Nutritious :>] However, I imagine Sam (the ...
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4 votes
2 answers
153 views

Is it possible for a blood type AB person to become type O temporarily?

I need a temporary mechanism for blood type switches for my modern love story, the protagonist is a werewolf and would transform every time when there is a full moon. I was thinking maybe a certain ...
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3 votes
2 answers
118 views

Why would a species from the Homo genus have overwhelmingly B negative blood type?

In my story (go to see What evolutionary pressures would lead to Ogres?), there is a massive species from the Homo genus called ogre. They mostly have B negative blood type (I do not mean Rhesus null, ...
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0 votes
2 answers
110 views

Using nanoparticles to give people blood clots for fun and profit

Some background: this question concerns iron oxide nanoparticles. Iron oxide nanoparticles are approximately 1 to 100 nanometers in diameter, as opposed to, say, a red blood cell, which is 10,000 ...
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1 vote
2 answers
118 views

How do I stop blood from clotting except upon exposure to the atmosphere? [closed]

Blood clots in order to stop bleeding. The problem is that sometimes it clots when it's not supposed to. This is called thrombosis. It kills a lots of people each year. I want this to stop happening. ...
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7 votes
3 answers
1k views

Despite having serrated fangs, why doesn't the vampire make a mess during a feast?

The vampire loves fresh blood and often sneaks into houses at night to feast. It would wait for nightfall when the occupants were asleep and then force their fangs into the neck of it's victims. ...
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7 votes
3 answers
318 views

What is the largest size a creature using hemocyanin instead of hemoglobin could reach?

I haven't been able to find much on this question. I am making a world that is fairly cold compared to ours, not quite a snowball planet but enough that the highest average temperature is 66 degrees ...
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3 votes
3 answers
529 views

How can a vampire produce T cells at home?

Let's say that there's a vampire that consumes human blood for a regular re-infusion of T cells - both a convenient way to explain why they don't need massive amounts of it (you only need a few, and ...
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1 vote
1 answer
109 views

What would the effects of a muscle-wrapped mesh of a circulatory system be on a human?

Let's say that there is a biomodified human. Their circulatory system is something of a mesh; there are artificial connections between their blood vessels wherever physically possible, generally at ...
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3 votes
3 answers
251 views

How could a vampire acquire specifically human blood without killing anyone?

I've seen a similar question posted here, but my vampires require specifically human blood. Anything other than human blood or water is disgusting and indigestible to them. Some more notes: Drinking ...
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2 votes
1 answer
137 views

Could a chemical be used to carry oxygen in blood that would also turn acidic when in contact with iron?

So, the general idea is this: A humanoid species' blood uses a chemical to carry oxygen throughout their system. When iron is introduced into their bloodstream by say, stabbing them, it results in the ...
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2 votes
1 answer
107 views

Would it be biologically advantageous for a vampire that doesn't need that much blood to lick away skin in order to extract it, rather than bite?

Let's say that there's a vampire that doesn't need much blood per day - something like a teaspoon. Instead of deriving nutrition from it, they need it for its antibodies, so that their nonfunctional ...
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3 votes
3 answers
733 views

A reality check on blood viscosity decreasing under high temperature

Is blood that decreases in viscosity as it increases in temperature plausible? It's supposed to be a biomodification that decreases the amount of energy the heart needs to put in during strenuous ...
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4 votes
2 answers
239 views

Moving air with a heart?

Could an animal, instead of lungs, have an extra circulatory system that pumps air instead of blood? It seems plausible that it would work with water, as water seems similar enough to blood, but air, ...
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29 votes
10 answers
6k views

Why would vampires require human blood?

In my world, vampires need to consume a small quantity of human blood every month to survive. They usually supplement their diet with animal blood and human food. A vampire which goes without human ...
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16 votes
5 answers
4k views

What would happen if a refrigerated bag of human blood was warmed up in a normal kitchen microwave?

I have a vampiric character who feeds on human blood. She can do your normal plastic hospital blood bags or from the vein, but obviously blood needs to be refrigerated in order to stay fresh and cold ...
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4 votes
1 answer
390 views

What color would humans be if our blood wasn't red?

Humans, currently, are varying shades of orange and brown. Sometimes paler humans are more of a reddish color. But what color would a human be if our blood was blue, green, or any other non-red color? ...
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4 votes
6 answers
288 views

What are some ways I can ensure that only a small amount of people actively try to pursue divination in a pre-modern society?

I'm trying to make a story where the amount of people that are able to see the future range from 1-0.1% (i.e. 1 in 100 to 1 in 1000). The problem I'm having is that I'm trying to have my cake and eat ...
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5 votes
3 answers
280 views

Is bi-metallic blood possible to develop organically in a species?

I've looked up the different "Colorations" of blood online, different metal-based proteins have differing levels of oxygen transfer efficiency, but those were answers I didn't find ...
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5 votes
2 answers
276 views

Biological Antifreeze In Blood

Okay, so I have a sapient alien species that has a carbon-based biochemistry, and is extremophilic, able to survive having their internal temperature lowered to as cold as 253 K. They are able to do ...
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3 votes
3 answers
607 views

How long would it take for inbreeding issues to arise for a family that practiced inbreeding?

The magic in my setting arises from inbreeding. However to gain the powers a person must be in-bred. How long would it take before such problems arise from inbreeding if the people continued this ...
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0 votes
1 answer
61 views

How do you transfer a blood curse? [closed]

The curse is made into a tea using the ashes of war, the blood of fallen soldiers, and the tears of their widows and then given to the victim to drink. Since the curse is in the victim's body and made ...
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18 votes
8 answers
6k views

How can a 15-year-old vampire get human blood?

Since they can't really work a job that would allow easy access to blood, I thought of having them volunteer at a blood bank then maybe steal a bag. Alternatively, is it plausible that they would come ...
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2 votes
2 answers
153 views

How would certain blood types be more susceptible to "blood bending" than others?

There exist abilities that are specifically tuned to certain individuals or clans. One of these strange abilities is known as blood-bending, which is the power to turn an individual's blood against ...
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5 votes
3 answers
274 views

Infectious hemophilia

I want to know if the disease I invented is realistic or a total fiction. Coagulopathies or bleeding disorders, like hemophilia, and Von Willebrand's syndrome, are diseases in which the blood's ...
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26 votes
4 answers
7k views

Would a vampire still be able to be a practicing Muslim?

I had debated whether asking this but given the very good answers on this question I thought it would be worth a shot. I have a character in my story who is a vampire and a practicing Muslim. ...
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8 votes
9 answers
3k views

If a scientist were to compare the blood of a human and a vampire, what would be the difference (if any)?

I tried to stick with vampire folklore and the various movies/shows about vampires when I thought of how vampires would be like if they really existed, but I also wanted to keep it as realistic as ...
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4 votes
1 answer
228 views

What would bloodstains look like after 500 years?

I realise this is a bit of a strange question, but what would bloodstains look like after ~500 years? Specifically, what would a text written on parchment using (human) blood as ink look like after ...
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4 votes
1 answer
508 views

What would 500 year old dried blood look like?

Imagine you are in a mountain cave (in the mountain, or under the earth), and you stumble upon a what seems to be a lake of blood. It's roughly 4mx4m (13ft) wide and 2m (6.5ft) deep. The blood is ...
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29 votes
7 answers
6k views

Can blood form snowflakes?

In a (marginally) cursed world rains of blood are an occasional occurrence. The water in the clouds is magically transmuted into blood at the point it starts to coalesce into droplets (no need to ...
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9 votes
1 answer
277 views

What blood pigment type is immune to ammonia poisoning?

I am designing a world in which the biological solvent is an ammonia-water mixture and need help finding out which blood pigments (Hemoglobin, Hemocyanin etc.) would be immune to the negative effects ...
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23 votes
5 answers
9k views

What colour would our blood be if our blood was based on gold? [closed]

Humans have blood based on iron, thus our blood is red. Some aquatic life has copper based blood, thus their blood is blue. If we were gold based, what colour would our blood be, and why? What would ...
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3 votes
4 answers
342 views

How do male vampire loses iron?

In my universe the vampire race all had pale skin due to low iron presence in blood and thus they had to constantly keep a certain level by feeding on human, the female vampire can lose a lot of iron ...
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-3 votes
2 answers
313 views

Could a blade rusted by dried blood become jammed in its sheath?

My character forgot to clean his sword after killing a man. The blade stayed for weeks in her sheath, drying the blood. I wrote a scene where he can't unsheathe his sword because it's "jammed&...
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4 votes
1 answer
263 views

Bio "blood magic" how would it work in science fantasy [closed]

I'm putting together a story that centers around "blood magic" and ancient civilization that uses some "rare crystals" as infinite source of Energy. the blood magic comes in gas form [from any source ...
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4 votes
3 answers
758 views

Do dead human bodies have a particular smell?

I'm working on a story where there is a crime scene where the protagonist (who has a superhuman sense of smell) notices a scent that smells like human corpses due to their abilities. I'm wondering how ...
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  • 13.3k
3 votes
1 answer
109 views

Colors of cobaltodihistidine [closed]

I have heard the complex, Cobaltodihistidine, (not coboglobin) mentioned several times on this site in relation to alternative oxygen carriers, and I believe that this complex could be what my species ...
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-4 votes
1 answer
86 views

How would blood types and blood transfusions work in a setting with widely different humanoid races? [closed]

This is something I think is almost always overlooked in science fiction settings. Do different races have completely different blood types from those of say humans? Could a Klingon from Star Trek ...
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0 votes
1 answer
110 views

Why would spell circles written in blood which contain iron be more powerful than using gold or silver ink? [closed]

Set in the 13th century A. D. the search for Philosopher's stone which is said to allow user to transmute base metal into gold or perhaps even diamonds as some have claimed. Since then people starts ...
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  • 46k
3 votes
2 answers
343 views

Would cold-blooded dragon be suitable for flying?

I am designing a cold-blooded dragon about the size of a house cat with a wingspan of 3 metres from tip to tip. It will climb on top of rocks at noon when there is ample sunlight overhead. I need it ...
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  • 46k
23 votes
15 answers
12k views

Where could a vampire get blood without harming people?

I am looking for possible ways in which a vampire could obtain blood to feed in an modern urban fantasy setting explicitly without harming humans or other sapient beings. Parameters for this question ...
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2 votes
1 answer
142 views

How to prevent vampires from catching bloodborne diseases? [duplicate]

Vampires are known to be humanoid creatures to whom the nutrients in blood are essential. I will assume that, for the purpose of this question, vampires are entirely human but consume blood, may it ...
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6 votes
2 answers
184 views

Could a blood transfusion from immune survivors of a deadly, bioengineered virus grant the same immunity to those who don't have it?

First question so hope I'm doing this right! Working on a setting right now where a bio-engineered virus/plague is wiping out a large portion of humanity. Most died upon first exposure. Some survived, ...
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  • 1,271
4 votes
1 answer
327 views

What kind of metal-based blood types be effective/used in transporting non-oxygen gases and what would their color be?

There's iridium-based blood called Chloro-carbonyl-bis(triphenylphosphine)-iridium that's effective at transporting hydrogen alongside oxygen. What I want to know is that, are there other metal-based ...
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8 votes
2 answers
598 views

Would it be possible for my fantasy creature to have black blood?

A friend of mine has a race of creatures in her headworld and has been wondering about a biological answer to justify the color of her race's blood even though magic is a bit sprinkled in there. One ...
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  • 433
8 votes
3 answers
602 views

Blood for hydrogen breathers

Some follow-up thoughts on this question... Hydrogen isn't very soluble in water. Oxygen is more so, but still sufficiently insoluble that most oxygen-breathing Earth creatures use special oxygen ...
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