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
138 views

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

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
80 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
149 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
61 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
33 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
81 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
5k 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
45 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
74 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
105 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
79 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
43 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
68 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
7k 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
136 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
39 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
1answer
33 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
162 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 ...
1
vote
1answer
63 views

Would somebody born 'reversed' (e.g. heart on their right side, etc.) be completely healthy?

By reversed I mean their body is a complete mirror image of a normal human's.
23
votes
4answers
11k 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?
7
votes
1answer
159 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 ...
32
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
44 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
135 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
139 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
27 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
6k 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
143 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
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0answers
27 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
23 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
40 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
35 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 ...
4
votes
1answer
5k 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
107 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 ...
8
votes
2answers
4k 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
61 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 ...
-5
votes
1answer
105 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
213 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
99 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. ...
0
votes
1answer
111 views

Does the DNA of a tadpole change after it becomes a frog?

Does the DNA of a tadpole change after it becomes a frog? In other words what changes take place as a tadpole becomes a frog, and does this metamorphosis affect the DNA in any way? I would appreciate ...
1
vote
0answers
49 views

How many mitotic divisions do haploid cells undergo before fertilization?

Background This question is about human physiology and gametogenesis. A spermatozoid is not necessarily the direct "offspring" of diploid cell. Stated differently, a spermatozoid cell can be the ...
2
votes
0answers
58 views

Is there any biological support for the concept of “chakras”? [closed]

Is there any support in modern biology for the ancient concept of "Chakras"? I've seen the concept of 7 chakras linked to the major endocrine glands in the human body (pineal,thyroid, adrenal, ...
-1
votes
1answer
183 views

Our muscles give us the ability to move our arms but…? [closed]

I have a strange question, but let me tell you something first. If you think of this carefully, then you realize something, please try this right now: Contract your muscles only so that your arms ...
1
vote
1answer
40 views

Difference between pulse and blood pressure

I'm a very naive and biologically illiterate person, and from what I've read on the internet I'm not really sure I understand the difference between pulse and ...
3
votes
1answer
99 views

Human bone density and Brown Bear bone density?

It is stated on this website that the density of a Grizzly bear bone is ten times our own. And since I am not into biology at all, I am confused as I don't understand the meaning of bone density here. ...
3
votes
1answer
125 views

What causes the line patterns in the palm of the hand?

The line patterns on the hand are unique to each individual, but what causes these lines and re they advantageous in anyway?
9
votes
1answer
122 views

Circadian Clock During a Flight

I am interested to know how does our Circadian Clock respond (and its resultant changes if any) when we are traveling across Time Zones? UPDATE 24th April I am reopening this question as the ...
2
votes
2answers
40 views

Help reading chromatogram

A genetic variation is found in this chromatogram: It says that the "reference sequence" is the top line and that I can use the general genetic code to find the reading frame. I can see that there ...
8
votes
1answer
693 views

What causes knuckle “popping” and the feeling of relief that comes from it?

Many people like cracking their knuckles. I have always been curious about it. What happens when we crack knuckles? What creates the POP sound? Why do we get a relief-like feeling after doing it?