This tag is for questions about the general biological features of human beings (as opposed to the biology of non-humans).

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1answer
82 views

Why do some women have menstruation-like spotting throughout their pregnancy?

An interesting question that was asked during a lecture about human reproduction: what is the biological mechanism behind some pregnant women getting monthly spotting that they mistake for a regular ...
2
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0answers
33 views

Viagra for pain management

Not all men who take Viagra experience any sexual side effects about 40% have no change of sexual abilities on the pill. However like many women the drug in such cases cause a strong pain reduction ...
5
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2answers
339 views

What happens to lactic acid I eat?

Let's say I drink some Kefir Milk, what happens to the lactic acid in the Kefir Milk that has entered my digestive system?
7
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2answers
308 views

Can humans transdermally absorb minerals from ocean water, and if so how much?

According to several studies quoted here, chemicals can be absorbed by the skin transdermally, at least under certain conditions. When it comes to elements in seawater like sodium, magnesium, ...
3
votes
1answer
130 views

Why doesn't Diabetes cause death by starvation?

The main cause for diabetes is lack of insulin in the body. Insulin is the hormone that allows body cells to absorb glucose from the blood. With out insulin, the body cells can't get glucose from the ...
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1answer
87 views

How HIV Affects and Its Treatment using Combination Therapy

Can someone please help me with the following questions. I've written my specific questions right after the text question. Human immunodeficiency virus (HIV) is a retrovirus. Its genome is a single ...
6
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2answers
143 views

How would the human body adjust to sleep times if we were to live in a place with different day lengths?

You sleep at night and are active during the day that's how things work for humans, but theoretically if a human whose parents lived on earth were to be born in another planet resembling earth but the ...
5
votes
1answer
46 views

Can neurotransmitter depletion cause short-term drug tolerance?

I'm curious to know if neurotransmitter degradation factors into drug tolerance and neural conduction and, if so, to what extent. As I recall from textbooks I read as an undergrad, one mechanism of ...
8
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1answer
591 views

What is the female equivalent of the morning erection that some men experience?

There was question about what causes "morning wood." It was answered that the erection in the morning is caused by decline of norepinephrine during REM sleep. Which in part allows to prevent ...
26
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1answer
4k views

What causes morning wood?

Sometimes men wake up with an erection in the morning. Why does this happen?
5
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2answers
74 views

biologically speaking, what's the difference between sleeping and just resting?

I can lay down in a rested position with my mind at ease, but no matter how relaxed I am or for how long i do it, it seems I'll still need sleep eventually. What's the difference - what is occurring ...
4
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1answer
35 views

What does hemozoin do?

My bio book refers to HEMOZOIN that is responsible for the shiver during malaria. How does hemozoin work to raise the body heat?
2
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1answer
34 views

Why does crying lead to a running nose and reddened nose tip?

Why do we have a running nose for quite some time after crying? It persists even after we stop crying. Why is it so? I have faced this always. Also, why does our nose redden on crying for long?
4
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2answers
224 views

How many different protein coding genes are in the Human Biome?

There are approximately 20k protein-coding genes found in the human genome. This number is presumably very small when considering all the genomes found in the diverse microbes associated with the ...
3
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1answer
41 views

Why do we feel cold on having fever?

Why do we feel terribly cold on catching fever of any sort, however our body becomes hotter? Why is it that a rise in temperature makes the sufferer feel colder? Also, sweating symbolises betterment ...
1
vote
1answer
53 views

People say the cardiac cycle depends on blood pressure? How so?

I know what the cardiac cycle is. There are two phases diastole and systole. One is the relaxed, and the other is the contracted form of the heart. The diastole is where blood is pumped to the ...
9
votes
2answers
600 views

Is there any biological reason that professional swimming is dominated by white people?

I suppose that the question should be turned around to "Why is it extremely rare to see black people competing in professional swimming?" because it is the absence of this phenotype while watching the ...
2
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2answers
1k views

Why aren't we allowed to refreeze previously thawed breastmilk in refrigerator?

https://www.breastfeeding.asn.au/bf-info/breastfeeding-and-work/expressing-and-storing-breastmilk Previously frozen— thawed in refrigerator but not warmed 4 hours or less (ie the next ...
5
votes
1answer
210 views

Would a spinal injury decrease human height?

A woman I know has been losing height at a rate of few cm a year following a severe spinal injury. How is this possible? What kind of injury could cause such progressive loss of height? Could this be ...
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4answers
2k views

Can nosebleed cause death?

Can Epistaxis or Nosebleed can be a of cause death?
5
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1answer
82 views

By what mechanism can hypoglycemia induce fainting?

Hypoglycemia (Low blood sugar) is said to be among the potential causes of human-faintings. I was wondering by which mechanism this happens. Google search results are abundant; there are lists of ...
3
votes
1answer
83 views

How much energy is required to blind someone?

As I understand the ravages of sunlight upon the (human) eye; the cause of ocular damage and blindness is too much energy delivered to the cones and rods that ultimately make up our eyes; so the ...
14
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4answers
2k views

Height and natural selection in humans?

I watched the documentary "Evolve" recently and in the segment on "size" Scott V. Edwards, Harvard evolutionary biologist mentioned the idea that humans might evolve to be 7' tall in 'hundreds of ...
0
votes
1answer
114 views

Schedules of mating for men

It’s simple deductive logic to follow that for a species to survive it must provide it’s offspring with the best possible conditions to ensure it’s survival – either that or to reproduce in such ...
12
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1answer
485 views

Supercomputer Vs Human Brain

With supercomputers doing calculation in petaflops ($10^{15}$ Calculations per Second), have we crossed the speed of Human Brain?
6
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1answer
45 views

Does fasting improves immunity?

I have heard that fasting causes regeneration of memory cells(B- and T-lymphocytes) thereby improving immunity.Is this true? If yes, how?
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3answers
827 views

Do probiotics survive digestion?

Pretty much this. I've been wondering if any of the yogourt and other "health" foods containing living probiotic cultures survive digestion to populate our intestines? If so, is there peer-reviewed ...
4
votes
1answer
38 views

Can you measure ECG from a single location?

I want to make a DIY bracelet to measure my ECG. All I need is the interbeat interval. Can I design a bracelet on one arm only, with two electrodes slightly spaced from one another, and figure out ...
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2answers
50 views

How to know if your breathing is normal?

Is it possible for a device to measure how much air we breathe in and out over the entire day and at what rate? I think if we have access to this data we can compare it across people.
2
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1answer
55 views

Is it dangerous to eat a mutated eggplant descended from a radioactive ancestor?

What is the risk, if any, associated with eating a 100th-generation mutated eggplant derived from a radioactive ancestor? In another word, is that possible that organic toxin will be produced by the ...
2
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1answer
77 views

Development of vitreous humor

I have tried reading about development of vitreous humor but it is all very confusing. When does it first developed ? Does it renew itself ? Please provide reliable sources..
4
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3answers
340 views

Are humans the only animal that requires “clean water”?

I've seen a number of animals - dogs, cats, squirrels, ducks and geese, etc drink from puddles, some of them were muddy, others had green flora growing under water. Same goes for lakes and rivers. A ...
4
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2answers
413 views

Does making yogurt from non-pasteurized milk work against possible disease bacteria?

In the past, when there was no pasteurization, could making yogurt from milk lower the chance of getting infected by bovine tuberculosis (or other diseases from infected milk)? For example, would ...
8
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1answer
429 views

Perspiration after drinking water

If we don't drink water for a long period of time(say,10 hours), as during fasting and then when we break our fast by drinking water why is it that our body starts sweating?
2
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2answers
139 views

Is it theoretically possible to treat filaggrin deficiency with a dietary supplement?

http://f1000.com/prime/reports/m/3/2/ "Filaggrin is a highly abundant protein expressed in the uppermost part of the epidermis that is critical to the formation and hydration of the stratum ...
4
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2answers
5k views

Does sour food cause sweating?

While eating sour food or candy, I start to sweat if it's sour enough. My body feels much hotter although my actual temperature is the same, my forehead starts sweating a lot and I feel like it just ...
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4answers
4k views

What nutrients can humans absorb in the mouth?

For instance, I realise being able to absorb simple sugars in the mouth is pivotal in the rapid action of oral glucose gel. Thus I was wondering what nutrients in general can be absorbed directly ...
2
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1answer
69 views

Is there any research paper state the pros and cons for human to be taller?

Is there any research paper state the physical health pros and physical health cons for humans to be taller? For example, shorter people seems to more likely to get involved in heart diseases and ...
2
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1answer
32 views

cerebral edema and blood pressure, pulse

What happens to blood pressure in cerebral edema; does systolic and diastolic rise equally? So the pulse actually slows down? Can't find anything about that, please help
2
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1answer
57 views

Biology Analogy

In my book are given several paired analogies with me being asked to give reason for them. I could solve all of them except this: liver = thrifty house-keeper I mean, I do not understand why the ...
4
votes
2answers
80 views

Do all humans experience flatus regardless of their diet?

Flatus frequency is affected by diet, so I was wondering if flatus production solely depends on the food eaten, meaning that some people never ever release flatus because they don't eat any ...
2
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1answer
420 views

How do you increase eumelanin but not pheomelanin?

Are Scientists currently looking into this?
3
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1answer
64 views

Does tea have its effect if you have a sleep after drinking it?

If I drink tea, then go to sleep for a while, when I wake up, will the effect of tea still be on me (the refreshing effect)? Does it depend on the duration of sleep?
1
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1answer
39 views

Neurology: spinal tract

I have had a few difficulties finding answers for the questions below. I have tried answering the first two myself; but, I am not sure they are correct or not. And I am not too sure about the third ...
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1answer
79 views

The distance the electromagnetic field of the heart can be detected

A very smart friend of mine seems to get taken in by junk science. He started telling me last night that the electromagnetic field of the heart can be detected beyond 30 feet. What is the actual ...
4
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1answer
55 views

HSL Lightness vs Eye sensitivity

In a monochromatic spectrum, is the human eye equally able to distinguish between lighter colors just as it is in distinguishing between darker colors? I mean is there really a linear relationship ...
7
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2answers
1k views

How do we know the presence of light when our eyes are closed?

Last night I laid on my bed and tried to go to sleep with the light off. I closed my eyes (but hadn't gone to sleep). My younger brother touched the wireless mouse (which had laser) for the laptop. ...
3
votes
1answer
103 views

Other than Acetylcarnitine what other orally-bioavailable Acetyl donors exist to assist in the conversion of CoA to acetyl-CoA?

I asked a question on bio stackexchange a few days from which I was hoping to be able to arrive at an answer for this question myself but I have had no such luck so now I am going to just ask ...
4
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3answers
287 views

Is the human body composition real?

In Fullmetal Alchemist when Ed goes to disprove to Rose the Sun God's "miracle" to bring humans back to life by proving that science (in the form of Alchemy) can create people by saying Water (35 ...
4
votes
1answer
319 views

What are the advantages and disadvantages of being ambidextrous?

What are the advantages and disadvantages of being ambidextrous? We have two hands and we nearly can't use one and this seems like a weakness, and a stupid one when you first think about it. But ...