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
166 views

How does the brain know where a signal came from? What is the addressing system

I am an electronic engineer so I am thinking about this from an electronics outlook. How does the addressing system work, As I see it, the nervous system is small parallel branches attached to larger ...
0
votes
2answers
102 views

Chills down the spine with certain music?

I am sure many of us know the feeling of that tingling chill down our spines when listening to certain music. I experienced this most when my younger brother played an emotional piano piece for a ...
4
votes
1answer
2k views

Why do sneezes come in pairs or more?

I very rarely sneeze just once, usually there's two coming in a row, and I've noticed the same thing in other people and even in animals. Is there any reason for this?
0
votes
1answer
60 views

Will we ever be able to read the thoughts from brain activity? [closed]

Is it theoretically possible to "read" a human's thought from brain activity? As far as I know we can already detect in what kind of mood a person is. Personally, I don't think "reading" word by word ...
2
votes
1answer
36 views

How usable is the Human Metabolic Model to predict biomass?

In order to use the Human Metabolic Model for Flux Balance Analysis of specific cancer cell lines, we would like to know what sort of flux values have been determined for the Human Metabolic Model. ...
1
vote
1answer
24 views

What are good data on the Human Metabolic Model and where can I get them?

Trying to get a good SBML representation of the Human Metabolic Model for use in Flux Balance Analysis and drug targetting (i.e. gene knockout) simulations. What are good sources for these data? ...
4
votes
1answer
80 views

Does playing music during sleep actually suppress rather than rouse the brain?

I've long been interested in the effect of music/sound on dreaming, and even built 2 apps that play music during REM period. Now I'm looking at this article about FMRI studies of a sleeping brain, and ...
1
vote
0answers
21 views

Is there a homeostatic setpoint for number of hours of sleep required by a human?

I've heard this TED.com talk about dieting and it mentions that there's a very definitive setpoint within the human brain about how much a human should weight. The speaker mentions that after as much ...
10
votes
4answers
20k views

What is the armpit hair for?

Modern human beings, especially women, cut their armpit hair. It seems to me the armpit hair is trivial/useless. Shortly speaking, what is the armpit hair for?
2
votes
2answers
75 views

Do humans have a “dominant” neurotransmitter system/sensitivity within their brain?

I've recently heard a podcast, in which Dr. Helen Fisher suggests that there are "4 broad personality types", and each one is associated with a particular neurotransmitter: The corresponding ...
2
votes
2answers
375 views

Are humans an eusocial species?

In the evolution of sociality among animals, different degrees are acknowledged. Some species present overlapping generations, some division of labor, and the minority present reproductive division. ...
3
votes
1answer
49 views

Gradual slowing breath, its effect on health

I've written a computer program which beeps, then beeps after 10 sec, then beeps after 11 sec, then beeps after 12 sec, etc. I tried the following "experiment" on myself: do only one breath between ...
-1
votes
1answer
52 views

What is the impact of prolonged electromagnetic exposure on human health?

What are the health effects of being exposed to a very strong electromagnetic field caused by two resonating superconductive coils (not static magnets) for a period of years?
0
votes
1answer
50 views

How does a smoker's pleasure work?

I smoke. For some reason, I've always had this idea that the pleasure of smoking works more or less like this: from the lungs, the nicotine reaches the blood, with which it travels to the brain, and ...
4
votes
4answers
15k views

How long human can survive with just drinking water everyday

Can humans live without eating food, just by drinking water? How long can we survive just by drinking water everyday?
0
votes
2answers
90 views

Rh factor and dominance of gene

"Formation of Rh antigen is controlled by dominant gene(R) and its absence by recipient gene(r).People having this antigen with genotype (RR or Rr) are called Rh positive and those whose blood ...
1
vote
1answer
91 views

Determining a patients biological age?

I am looking for an algorithm that shows the exact coefficients some variables that have on a hospital patient's chronological age versus their biological age. I understand a lot of the variables ...
2
votes
1answer
51 views

How good is information transfer between the hemispheres of the brain?

I sometimes listen to lectures on my phone using ear buds, but occasionally with only one ear bud in. Is the other half of my brain losing out on any aspect of the lecture? Just how good is the corpus ...
0
votes
4answers
103 views

Significance of having goosebumps?

What help does goosebumps do to us? I don't think it helps us noticeably when we are scared or shivering.
13
votes
5answers
5k views

Origin, or source, of rhesus negative in human blood

This is my first post here, so please be gentle. I recently learned that I have Rh- blood (I'm A-), and was idly looking into blood types on Wikipedia. I was surprised to find that relatively few ...
0
votes
0answers
26 views

How to predict the position of the femoral head center given surface anthropometric data?

Given surface measurements such as hip breadth and hip depth, how would you predict the location of the femoral head center?
2
votes
2answers
4k views

What could cause hairs to gray at the tips but not the roots?

I have noticed that some of my sporadic gray hairs are gray at the tip side but oddly, not near the roots. Some are even only gray in the middle. I find all of this very counter intuitive, and I ...
1
vote
1answer
76 views

Breathing in and out

I was reading my textbook and it says that breathing involves inhaling and exhaling but it doesn't say whether they happen simultaneously or sequentially. Also is my overall understanding of ...
1
vote
1answer
54 views

How suddenly does lactose-intolerance onset?

How quickly can the loss of lactose tolerance onset in an adult? Such as being able to process lactose normally to having notice symptoms associated with the inability to process lactose. I am not ...
0
votes
0answers
14 views

Why do our limbs and other body parts get numb/feelingless and then they start to tickle? [duplicate]

Why do our limbs (legs, arms) get numb/feelingless when they are under prolonged pressure or when one has crossed his/her leg while sitting for a long period? After we move it to a more relaxed or ...
18
votes
3answers
14k views

Why do mammalian red blood cells lack a nucleus?

How did the red blood cell in humans get to lose its nucleus (and other organelles)? Does the bone marrow just not put the nucleus in, or is it stripped out at some stage in the construction of the ...
0
votes
0answers
45 views

Is it possible for a human and another ape species to reproduce? [duplicate]

Is it possible for a human and another species to reproduce?
4
votes
0answers
59 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 ...
6
votes
4answers
1k 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?
4
votes
4answers
2k views

How long can a naked human survive on Mars?

How long can a naked human survive at the surface of the Mars planet? For instance, let's say a worker's base takes fire while he sleeps, and he has to run to the emergency building 200 meters away ...
2
votes
2answers
64 views

Are B Cells unique to an individual's immune system?

I was wondering how the body "remembers" viruses after having once overcome them, and while reading this article on the immune system (page 14, Vaccinations), I read: There are many diseases that, ...
4
votes
1answer
2k views

How does prolonged exposure to high frequency noise affect hearing?

Is there any research showing how prolonged exposure to background noises, particularly high frequency noises, affect hearing abilities? Does constant high pitched noise cause damage even a low ...
2
votes
1answer
211 views

Why apes started to contemplate and become altruistic? [closed]

I was asking this first on philosophy forums, but it is suggested, that answer could be found from evolutionary view of point, so here we go: Again my question raised when thinking of myths, their ...
32
votes
5answers
964 views

Human perception of time depending on age

From what I can tell and what thus far all people with whom I discussed this subject confirmed is that time appears to "accelerate" as we age. Digging a little, most explanations I found basically ...
19
votes
1answer
284 views

Extremely rare occurence of Heart cancer?

The occurrence of Heart cancer (similar, but not the same as Rhabdomyosarcoma) is extremely rare, about 1 per year according to MayoClinic. The reason for this rarity is explained to be the ...
1
vote
1answer
68 views

What stops the coagulation process?

Whenever there are minor/major injury to blood vessels, the platelets, fibrin, thrombin, etc. are recruited. They then seal the wound and block bleeding. What tells them that their job is done?
1
vote
0answers
80 views

Why are people tired after surgery?

I had surgery when woke up I felt like I only had 20% energy & felt extremely tired. Is this a common sensation? Why do people feel so tired after surgery?
1
vote
0answers
37 views

Why does the ovum prefers to be arrested at metaphase 2 of meosis before fertilization? What is the possible advantage of this process?

Why does the human ovum prefers to be arrested at metaphase 2 of meosis before fertilization? What is the possible advantage of this process??Please help me with it.
12
votes
1answer
1k views

Why does looking at bright light trigger sneezing in some people?

Why does looking at bright light trigger sneezing in some people? Are there any recent studies that have found a cause for this Photic sneeze reflex? The Wikipedia article only references studies ...
2
votes
1answer
49 views

The arrangement of retinal cells?

The section of retina shows a layered arrangement of the various retinal cells. Starting from the inside (where the light strikes first) is the nerve fibre layer, ganglionic layer, amacrine cell ...
2
votes
1answer
41 views

When does identical twinning happen?

What is the window during which division into twins is possible (for instance can it still happen after implantation in the uterus)? Is one twin the "original" and the other its clone?
0
votes
1answer
82 views

Current human behavior as a genetic heritage

People: I have doubts about genetic heritage, but let me explain the context which has shown up this doubt for you: I was debating about sexism and the following question were put on the discussion: ...
0
votes
1answer
609 views

Structure of adenoids

I am not sure this question belongs in biology, but I can't find a more suitable stack exchange site, feel free to delete it if this doesn't fit here. Also, this question is going to be slightly ...
2
votes
1answer
154 views

Are inflammation and anxiety connected?

I've been reading a curious paper about the use of cannabis, and one of the passages piqued my interest: There’s also been a lot of work done on another constituent of marijuana, cannabinoid, ...
5
votes
2answers
52 views

Standard Classification of Disease

I am working on a project for health center. It involves the creation of a database of all diseases. Currently I want to classify disease on the base of their category based on international standard. ...
3
votes
2answers
505 views

Ill effects of urea and NH3 on metabolism

What exactly does urea do that harms our body? Does it interfere with our cellular processes or disturbs the colloidal onchotic pressure of our blood? I have heard that $NH_3$ damages the brain. What ...
3
votes
0answers
152 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
0answers
40 views

Database of Medical Assertions

Can anyone point me toward a computationally-accessible database of medical assertions? I'm looking for something where each row in the database contains a single unit of knowledge. It could either be ...
2
votes
0answers
75 views

How is color information transmitted from eye to brain?

Is it frequency-modualated or are different colors transmitted by different axons? I know that each ganglion cell is connected to multiple photoreceptors. How does it tell the brain which ...
3
votes
2answers
114 views

Why do our eyes “wrap” hue from UV to IR?

On the high-wavelength side of things, we see almost-infrared as reddish, with a slight tinge of magenta. On the low side, we see violet fading into the same magenta color. Why is that? You can see ...