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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3
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2answers
59 views

Myopia as a microscopic superpower?

A few years back my Physics professor made a joke that his myopia (i.e., nearsightedness) gave him a "superpower" that allowed him to see close objects much more clearly than someone with typical ...
4
votes
0answers
26 views

How pronounced is the difference if we would change the running direction for runners?

I was jogging when I asked myself this question: In running contests the standard running direction is counterclockwise; I also believe to remember that the regulation is very old (right back to the ...
5
votes
1answer
76 views

Why do we get tired [on hold]

At the end of a day full of work, it is general for people that their eyelids start to feel heavy. Laziness takes over and we begin to yawn. We all know that we're tired at that time, but why people ...
5
votes
1answer
35 views

How do I know which alleles the parents have?

I have the following assignment where I am to look at the "tree" (not sure the english word) and assign whether or not they can be autosomal dominant or recessive as well whether they can be X-linked ...
6
votes
1answer
382 views

Evolution of umbilical cord and reason of its elongation

To answer a question myself, recently I've read that Years and years ago, a long umbilical cord enabled a woman to grasp her baby after birth and run away from predators" Update: $Question:$ ...
2
votes
1answer
37 views

Explanation of ECG in MI using an electrostatic model

I found a paper presenting an electrostatic model to explain the ECG recorded in various leads. This model essentially calls for considering the depolarization wavefront to be the major contributing ...
-4
votes
1answer
60 views

How does visual sexual arousal work between the eyes, brain, and genitals/gonads? [on hold]

When many people look at sexual images, they often can become sexually aroused, including full genital arousal, and feel urges, known more often used as "horny" as slang/urban usage. How does this ...
1
vote
1answer
43 views

Does homeopathic or herbal treatment of cancer have any scientific recognition?

Even though we have a very high tech society, cancer is still a serious issue. We humans still are not entirely capable of fighting cancer. Radiation and chemotherapy are still considered the best ...
9
votes
1answer
109 views

Can people with paralyzed eye muscles see?

As far as I am aware, the saccades of the eye are central to visual perception. If the eye is held still, the human stops seeing, even if light is reaching the retina and the visual pathway is intact. ...
1
vote
0answers
44 views

Why my right eye see warmer colors? [closed]

As the title says, my right eye see warmer color than the left one. I've seen a few people talking about that thanks to google, but I was unable to find a proper answer. So, what cause this strange ...
4
votes
0answers
21 views

Is it possible that the vapour form of propylene glycol could lower a humans blood oxygen saturation by the manner in which N2O does?

My understanding is that by inhaling nitrous oxide leads to the body not being able to take in as much oxygen as it usually would. Is it possible that a heavier soluble gas such as the vapour form of ...
6
votes
1answer
69 views

How can one accurately diagnose the cause of human hearing loss without surgery?

In a human, if you were to avoid a tympanotomy (surgical examination of the middle ear), how could you distinguish between a blocked Eustachian tube, a ruptured eardrum, or a perilymph fistula? For ...
9
votes
2answers
4k views

Why does it hurt when you take sweets, if you have cavities in your teeth?

When you have cavities in your teeth taking any sweetend drinks or food causes sensitivity or pain. What could be the reason?
2
votes
1answer
38 views

Help reading gene markers

I'm sorry if "gene markers" is not the correct word. An edit could be appreciated but I don't study in an English speaking country unfortunately. Question overview: In a family, there is a genetic, ...
8
votes
1answer
70 views

What processes are responsible for focusing on an image only seen by one of the eyes?

When a person is spying from around a corner with only one eye, it's rather easy to ignore the other eye's image, since it's probably much darker, because one usually spies around a corner standing ...
5
votes
1answer
77 views

Effect of closed eyes on balance?

Suppose you want to stand on one leg. Doing it eyes open is not that difficult, but doing it eyes closed seems to be difficult. Why?
3
votes
1answer
71 views

What is the impact of stress on the human body?

Can stress trigger any changes in the human body? I'd like to know more about things less commonly known than, for example: sweating and tiredness. What are the long term risks of chronic stress? Do ...
4
votes
0answers
35 views

Does anxiety about weight or eating cause people to become overweight?

A while ago I saw this TED talk about the futility of dieting. The speaker suggests that a body maintains a homeostatic weight point and returns to that weight after dieting has stopped: Turns out ...
2
votes
0answers
46 views

Can DNA test of my grandparent's brother reveal my heritage from that branch of the family?

I'm thinking about doing that DNA test on all my grandparents to know where their genes come from. They are getting very old and I don't want to let the opportunity pass to gather more knowledge about ...
14
votes
2answers
5k views

Can one die from pain?

Is it possible that a human or any other creature can die from pain? I googled and found different answers. Some articles say Yes while others say No.
14
votes
2answers
3k views

Will humans and animals be harmed by frequencies outside their hearing range?

The human ear (for example) is sensitive to frequencies from 20Hz to 20kHz. Any sound beyond that limit would not be heard by us naturally. Will it harm us (effect our ability to hear) when we hear ...
7
votes
1answer
133 views

Counterintuitive action of Vitamin D?

Vitamin D acts in a way which to me is counterintuitive. It functionally supplemets Parathormone. It in the intestinal tract steps up calcium absorption by altering nuclear gene expression and also ...
0
votes
1answer
22 views

How is cancer associated with host pathogen interaction?

Does cancer by any chance fall under host pathogen interaction domain? What I mean to ask is that, is there pathogen interaction involved in cancer? I went through this article: ...
0
votes
0answers
11 views

Phytoestrogens from hops in beer and estrogenic activity in humans

There is a saying that phytoestrogens from hops can cause male boobs in male beer drinkers. Are there any reliable studies linking beer consumption to increased estrogenic activity? In males and ...
0
votes
1answer
25 views

What is meant by clonal isolates?

With respect to this website: http://horfdb.dfci.harvard.edu/ what does the term clonal isolates mean?
2
votes
2answers
116 views

Is there a known glucosepane cross-link breaker?

I read the following on wikipedia: There is, however, no agent known that can break down the most common AGE, glucosepane, which appears 10 to 1,000 times more common in human tissue than any ...
0
votes
1answer
49 views
21
votes
4answers
9k views

Can humans eat grass?

Can a human eat grass and digest it? Could it be possible to use it as food just like other plants such as wheat or beans?
6
votes
1answer
71 views

Why is the brain dependent on glucose?

The strict dependence of the (human) brain on glucose has always been puzzling to me. While ketones can substitute for a portion of the brain's energy needs, it cannot substitute completely: blood ...
30
votes
1answer
4k views

What causes morning wood?

Sometimes men wake up with an erection in the morning. Why does this happen?
0
votes
1answer
42 views

Why do teeth decay of sugar?

Sugars is a common component in diet of mammals. Why then their teeth did not develop resistence to sugar decay?
1
vote
1answer
131 views

Interlocus Contest Evolution means suicide?

I was reading Matt Ridley's "Genome" book. I am trying to understand the Interlocus Contest Evolution in his X-Y chapter. I do not understand why the X and Y chromosome would want to kill each other. ...
0
votes
3answers
84 views

How does frame-shift mutation not absolutely ruin the organism?

I'm a bit curious as to how frame-shift mutation works. If you shift one amino acid towards another. How does this not affect the entire chromosome? Wouldn't this mean that the organism would be ...
0
votes
0answers
14 views

Over what range do Thyroid Stimulating Hormone (TSH) levels tend to fluctuate over the course of a day?

I understand that the majority of doctors consider the TSH test "the gold standard" for measuring thyroid function (examples stating that literally are here and here). The reference range for what is ...
10
votes
4answers
5k views

How does sodium in one's diet affect blood pressure?

Due to high blood pressure, my doctor has recommended I go on a low-sodium diet. So, that got me wondering what it is about sodium that drives this recommendation? What does sodium do to a body ...
15
votes
1answer
86 views

Why does mint oil feel cold on the skin?

When putting (japanese) mintoil on the skin it produces a cool feeling. You can experience this, when adding it to your bath or using a spray with mint oil on your skin. The cool feeling occures ...
0
votes
0answers
24 views

Regarding benzoic acid and its effects

One of the users on the chemistry s.e. mentioned that when benzoic acid forms in the body in response to other chemicals it might have a mutating effect on one's DNA. Is this true?
1
vote
1answer
20 views

Human population growth - where can I find the data?

Out of curiosity, I'd like play around with data of human global demography. Where can I find data that describe the "per region (per continent for example) population size" versus time since the ...
1
vote
1answer
19 views

What causes muscle spasms?

What causes muscle spasms with muscles that are not in the heart ? Could it be some sort of stimulus overload that causes a massive contraction?
0
votes
1answer
29 views

How does cancer of the larynx (laryngeal cancer) affect the respiratory system?

The larynx is part of the respiratory system and is responsible for producing sound (our voices). My question is how cancer in the larynx (voice box) affect the respiratory system overall? I ...
1
vote
1answer
38 views

Feeling of spicy

I have done a survey on my friend When everytime they eat something spicy, They will eat ice or drink icy water. First, Mostly they feel nothing but a cool sensation. However when they finished, they ...
4
votes
1answer
3k views

Applying saliva to mosquito bites

Is it true that; when you apply your own saliva to a mosquito bite it would stop itching ?
2
votes
1answer
44 views

What happens when we stretch?

From the wikipedia page on stretching: Stretching is a form of physical exercise in which a specific muscle or tendon (or muscle group) is deliberately flexed or stretched in order to improve the ...
3
votes
1answer
50 views

Bayes theorem for mutations

MEN 2A is a dominant inherited disease caused by a mutation in the RET proto-oncogene. The probability of being sick when you have the mutation of the RET proto-oncogene varies with age and is assumed ...
6
votes
2answers
3k views

Do biological facts determine when a human fetus is considered alive and human?

I often hear or read this statement: "It's not a human, it's a fetus." In other words, some think a fetus is non-human until a certain point. And another similar statement: "The fetus isn't ...
4
votes
1answer
35 views

How can a heart of human work if one of its valve is not working?

Yesterday I went to a hospital and heard a doctor say that one of the heart valves of a patient is not working. However, the patient was still alive and was healthy; the patient could walk and talk ...
2
votes
1answer
95 views

Is homosexuality an adaptation in humans?

Homo sapiens have menopause - as some other mammals (e.g. some Cetacea) - a phenomenon where older females live for decades after the end of their own reproduction. Perhaps homosexuality, that looks ...
-5
votes
1answer
60 views

Why do fingers swell during cold winters?

When exercising, tissue in the hands may swell. This may be caused by the muscles generating heat, which leads to blood being pushed to the vessels closest to the surface of your body to dissipate the ...
0
votes
2answers
40 views

Why is my peripheral vision better for seeing in the dark? [duplicate]

I often walk around my house at night with the lights turned off and one night I noticed that looking straight at an object with very little light available made the object disappear from sight but if ...
4
votes
1answer
84 views

Do human-ape hybrids exist?

Since humans and apes share up to 99% of their DNA, can they interbreed? For example, a horse and a donkey seem to be just as distantly related and produce offspring. Mules, however, are sterile. ...