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

learn more… | top users | synonyms

0
votes
0answers
2 views

Can my eyes adjust instantly to my friend's glasses?

My eyesight is pretty much perfect, but I noticed that whenever I try any of my friends glasses, from really thin to extremely thick, my eyes seem to adjust to them within seconds and let me see ...
2
votes
1answer
126 views

Is there a hormone combination that makes humans grumpy?

Imagine a typical situation that is likely to give rise to a bad temper within an individual: a person is awoken very early in the morning by a sound of a lawn being mowed next door. Unlike expected ...
-1
votes
0answers
14 views

Is it possible for me to grow another inch? [on hold]

I'm 14 and a half, 5'6, and got my first period at 11 and a half. My mother is 5'5 and my dad's 5'10. Can I still grow another inch? If it helps I was 5'4.5 for 2 years but i grew the inch and a half ...
0
votes
0answers
10 views

Why people sweat while eating chilli? [duplicate]

What chemical causes chilli its chilliness? Also, while eating chilli, people sweat and their nose become watery and they tends to expose their tongue to cool it. What is the reason for this ...
3
votes
3answers
19k views

What is it called when one human eye is seeing brighter color than the other?

What is the name of a phenomenon where one of the human eyes is seeing brighter/more saturated color than the other? I can observe the same object from the same position while alternating which eye is ...
1
vote
2answers
43 views

What would happen if brain neurons did not reduce their sensitivity to neurotransmitters after prolonged exposure?

From my understanding, neurons decrease their sensitivity to neurotransmitters by reducing the amount of receptors on the cell membrane in response to sustained neurotransmitter activity. One ...
1
vote
1answer
26 views

Bernoulli’s Principle in 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 ...
2
votes
1answer
20 views

Do the enzymes and compounds in saliva help with stain removal?

Does spitting on stains help with removal? Saliva is high in amylase that should help with the breakdown of protein rich stains like blood and semen. It also contains antimicrobial enzymes and ...
3
votes
1answer
56 views

Is there a schema for how human behavior is genetically determined?

It seem one can distinguish three different kinds of genetic determinism of common patterns of human behavior: behavior that is directly wired into our nervous system, e.g. face-related mirror ...
1
vote
0answers
106 views

Which of these methods is both effective and reliable in elongate muscle and tendon for use in humans: growth factors or stem cell technology

Which method is it the most effective, but also the most reliable for elongating muscle and tendons for clinical trial; using modern growth factor technology or using modern stem cell technology? ...
7
votes
1answer
63 views

What bacteria do unborn babies contain?

This Scientific American article states that "[human] infestation [by bacteria] begins at birth". This would suggest that unborn babies are free from any bacteria. However, if the mother catches a ...
12
votes
4answers
5k views

Why we have no enzyme to digest cellulose?

As we know, cellulose is the most abundant polysaccharide in nature. Why don't we have any enzyme to digest cellulose?
0
votes
0answers
14 views

Why we see a reddish vision in dark room after seeing a bright light?

When you enter a dark room after seeing sunlight or other bright light, you see a reddish speck of light hovering around your vision. This vision generally disappears after a few minutes. Why this ...
13
votes
1answer
15k views

At what age do babies begin to synthesize their own antibodies?

When babies are first born, they receive their antibodies from their mother (I assume because they do not yet have the capacity to synthesize their own). So my question is, at what age do babies ...
3
votes
0answers
39 views

How long does conception take?

I know that conception is a multi-step process. A sperm fuses with an egg. Its contents diffuse into the cytoplasm. Dad's DNA is transported to the nucleus. Proteins are gradually made from Dad's ...
-1
votes
0answers
33 views

Heart Rate while Eating?

I was wondering does heart rate increase during the consumption of food (chewing, starting the digestive system)?
0
votes
0answers
38 views

Why does water feel colder than air at same temperature? [closed]

If you go swimming and the water is the same temperature as the air, when you first jump in, the water feels colder then air temperature. I guess this has something to do with Heat-Conduction, like ...
0
votes
0answers
30 views

How to mimic / approach some animals/insects' anabolism?

This article states that some shelled animals - spiders, scorpions, crabs, worms and other creatures - have metal atoms in their claws, jaws and fangs. I believe through anabolism, since they eat ...
3
votes
1answer
69 views

Do our belly buttons consist of scar tissue?

I read an interesting post on Facebook the other day saying that we all have a visible scar since birth - our belly button. This got me thinking (and research for me only found results regarding belly ...
1
vote
1answer
64 views

Is each generation getting older? [duplicate]

So we know that our sperm and egg cells get set aside relatively early so that they aren't going through unnecessary cell divisions and causing DNA damage or telomere shortening, but since each new ...
3
votes
0answers
35 views

Is there a mechanism by which mammals lose interest in a partner after mating?

I'm reading the book called "Cupid's poison arrow", which revolves around a rather simple assumption: most mammals, including humans have a genetic program that is responsible for ever increasing ...
8
votes
1answer
522 views

Why do people feel pleasure when using roller coasters / centrifuges?

The feeling when using an amusement park unit is usually a pleasure. Why is it not a pain instead? Are there advantages, from an evolutionary point of view, in loving this potentially dangerous ...
3
votes
0answers
22 views

Why are humans mostly right-handed? [duplicate]

Most sources I've seen say that about 90% of humans are right handed, and 10% are left handed. Why is this? My only guess would be that it has something to do with different parts of the brain ...
7
votes
2answers
159 views

Are unilaterally deaf people able to determine where sound comes from?

My question is on people deafened in one ear, but normal hearing in the other. Time and level differences between the two ears are only part of how the human body can localize the source of the ...
4
votes
1answer
809 views

Is there a relationship between Melatonin, Norepinephrine and depression in humans?

I'm reading a booklet on melatonin published in 1996, titled "Melatonin and the Biological Clock". This particular paragraph caught my attention and I would like to better understand what it means: ...
5
votes
4answers
6k views

Can nosebleeds cause death?

Can epistaxis or nosebleeds be a of cause death?
14
votes
2answers
715 views

Why does mouldy food make you sick?

Bread gets mouldy pretty quickly, and my parents (both of whom are nurses) throw out a loaf of bread after a spot of mould is seen (because "if you can see one spot, it means the whole thing is ...
2
votes
3answers
103 views

Blood urea nitrogen and usage of proteins?

I have been reading some books and am getting slightly confused. Here is roughly what I have read. The greater the blood urea nitrogen the greater the usage of proteins (since blood urea nitrogen ...
8
votes
4answers
465 views

Why people like to see pornographic scenes, but do not feel the same about eating scenes? [closed]

This question may seem funny, but I think biology must have good answers. I think no more explanation is needed. I really thought about this and searched for an answer, but there is nothing yet. If ...
9
votes
1answer
343 views

How do female hormones cause blood to clot?

On most female-hormone supplements you get a warning that is something like this: The use of a combination hormonal contraceptives (CHC), like NuvaRing, is associated with increased risks of ...
6
votes
2answers
7k views

Does mixing alcoholic drinks really make you more drunk?

There is plenty of anecdotal evidence ("beer after wine and you'll feel fine, wine after beer will make you feel queer") that mixing alcoholic drink types leads to a stronger effect, but I can't find ...
10
votes
3answers
233 views

Why are the organs for reproduction and urinary excretion combined?

We eat food for getting energy to our body parts, and we excrete the wastes through urine, feces, and perspiration. Why has nature combined the urinary tract with the genital system (urogenital ...
2
votes
1answer
29 views

Why are our bodies created to itch when histamine is released by our immune systems?

Why do bug bites and cuts itch when scratching them clearly doesn't help us survive? Did our early ancestors need to rely on this itching sensation, or is it just that the receptors for itches just ...
2
votes
1answer
33 views

Why is there a compound highlighted in red in a KEGG Module search?

Considering the following module: http://www.kegg.jp/kegg-bin/show_module?M00115+C00003 why is the compound C00003 marked in red?
1
vote
1answer
13 views

What information does the KEGG Module statistics page show?

While browsing through the home page of KEGG Module, I clicked the button named Module statistics. Can someone tell me what does these numbers signify? What are they the statistics of?
14
votes
1answer
20k views

Can a person really die quickly from biting their tongue?

A common trope in certain circles (like Eastern martial fiction), is someone committing quick suicide by biting his or her tongue. But is this really possible? The internet turns up millions of ...
0
votes
1answer
35 views

Would a human survive eating only living ants?

After reading an admittedly foolish question about 1 googol ants vs. 1000 humans, I had a question. Could a human survive solely on eating ants (common ants, not the stinging kind, or leafcutters ...
0
votes
0answers
53 views

Phytoestrogens from hops in beer and estrogenic activity in humans

There is a saying that phytoestrogens from hops can cause breast growth (gynecomastia) in male beer drinkers. Are there any reliable studies linking beer consumption to increased estrogenic activity? ...
5
votes
1answer
1k views

Is the Michael Jackson skin pigmentation disease realistic?

Quoting wikipedia: Jackson's skin had been a medium-brown color for the entire duration of his youth, but starting in the mid-1980s, it gradually grew paler. The change gained widespread media ...
1
vote
0answers
20 views

An obscure reference to a “golden vein” [migrated]

In some Yiddish literature there is reference to a 'golden vein' which seems to refer to Hemorrhoids. Is there any reason that hemorrhoids would be described as golden? Edit: In response to the ...
3
votes
1answer
53 views

What are the most important factors influencing a person’s gut microbes?

You are your bacteria! The probiotics and the antibiotics... There has been on going discussions about how our gut bacteria is important for a healthy lifestyle. Figure 1: Schematic diagram ...
16
votes
4answers
2k views

Where’s the flaw in my proposed TB Treatment?

Ten years ago, I emailed a prominent lung specialist with my suggestion for a treatment for Tuberculosis. His lack of response led me to believe that the idea had no merit whatsoever – but I had no ...
19
votes
1answer
4k views

What do you see when your eyes are closed?

If you are in pitch black and you close your eyes, you sometimes can see strange shapes of various colors. A lot of the time these shapes and colors change as you observe them. This phenomenon still ...
3
votes
1answer
84 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 ...
0
votes
1answer
22 views

Why can't this be 1st meiotic division non-disjunction as well?

The child has gotten 2 "sick" chromosomes from his dad and 1 healthy from his mom, leaving it with trisomy 13. I can see how this can happen in the second meiotic division of the father but I can ...
2
votes
1answer
55 views

How does Celiac's Disease cause people to stop growing?

In all of the sites I've looked on, one of the symptoms of Celiac's Disease is the failure to grow in children. Why would an immune attack against gluten cause stunted growth? Celiac.org states: ...
3
votes
2answers
121 views

Is there a short-term, very strong anesthetic, which can be blocked/delayed by other substances?

Question migrated from World Building SE. (For fictional use only, of course :) ) I am looking for an anasthetic which fulfills the following criteria: very strong effect, induces a comatose state ...
12
votes
2answers
2k views

How was birth control realized in ancient days? [closed]

In ancient days, there were no birth control methods like condoms or contraceptive pills available. How did they control pregnancy?
4
votes
4answers
219 views

Why can't you just take a vitamin? Why you need a healthy diet on top of that?

From what I understand, your body needs certain amounts of vitamins and minerals to maintain health. Why can't we just take enough pills to obtain these vitamins and minerals?
-4
votes
1answer
77 views

How significant is the genetic component of homosexual behaviour?

From some basic googling, I found that nobody has ever proven that people are born gay and that environment plays a great part in homosexuality. I wish to know if there is a genetic component to ...