Biology pertaining to humans
3
votes
2answers
142 views
Why people like to see pornographic scenes, but do not feel the same about eating scenes?
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 ...
4
votes
0answers
43 views
Is human face more resistant to cold than other body parts?
Walking outside tonight in -15˚C I realized an interesting observation: While I felt cold on most part of my body, my face (although the only uncovered part) didn't really feel cold. It registered the ...
3
votes
1answer
73 views
Are there records of monozygotic twins in which one experiences androgen insensitivity syndrome
I have given my high school biology students the thought experiment of "What would happen if a researcher induced twinning of a female zygote and then replaced one of the X Chromosomes with a copy of ...
10
votes
1answer
205 views
Why is cold water more refreshing than warm water?
Obviously, the temperature of water does not affect its chemical composition. At least not in the ranges we are likely to drink it in. Yet it is clearly far more pleasant and refreshing to drink cool ...
2
votes
1answer
118 views
Which blood vessel carries the most impure blood?
There is a question in my Biology textbook:
"Which blood vessel in the human body carries most impure blood after
few hours of meal."
The answer is given as Renal artery.
But I think the ...
1
vote
0answers
43 views
What are the physiological effects of wine?
I have read that alcohol in general and wine in particular can have advantageous as well as detrimental effects on human health. Is this true? What are the physiological effects of consuming wine in ...
3
votes
1answer
56 views
Where does all the food go?
Food goes in, excrements come out. This seems obvious.
But it seems like the mass of the excrements is less than the one of the food.
Most people I asked answered: "There's a difference because it's ...
2
votes
2answers
591 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 ...
4
votes
1answer
53 views
What kinds of arousal can a human brain experience?
I've been reading about the new phenomenon called "arousal addiction". The context in which this term is used is Internet, Porn and/or video game addiction(cummulatively Internet Addiction Disorder - ...
3
votes
2answers
156 views
How does HCl does not burn our stomach?
How does the digestive acid (HCl) not burn the surrounding skin of our stomach? It digests majority of raw food we eat but how does it stays safe in our stomach? Also, how does the stomach retains the ...
18
votes
2answers
3k views
If a human takes antibiotics are all bacteria in the body killed?
From my basic understanding, antibiotics kill living things, bacteria for example.
Do the antibiotics consumed by a human-being distinguish between what they kill? Or do they just kill every bacteria ...
4
votes
2answers
172 views
Effects of exercise on the brain
I am well aware of the phenomenon of neurogenesis induced by exercise, as well as the dopamine release that results from exercise. I am really interested in neuropsychology and the effects of exercise ...
8
votes
1answer
641 views
What influences the timing of human bowel movements in the morning?
I'm trying to understand if the timing of human bowel movements in the morning is associated with the circadian rhythm, and can thus be used to make predictions about the circadian rhythm.
What ...
6
votes
1answer
70 views
Does artificial heat (shower/tea) affect diurnal rhythms in humans?
I've been reading that over the course of the day, human body temperature follows diurnal rhythm with the lowest body temperature observed some time close to the middle of the sleep episode, while the ...
5
votes
1answer
118 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 ...
2
votes
1answer
51 views
Do siblings have a bias toward believing they look different from each other?
Anecdotally, I have observed (myself included) that siblings tend to think that they look less similar to each other than an unrelated observer would say. Is there any experimental data to back this ...
8
votes
1answer
56 views
Are homozygous carriers of the CCR5-Δ32 allele fully immune to all known strains of HIV?
Or is there documented evidence of even one homozygous carrier contracting HIV and staying infected?
3
votes
2answers
173 views
What is the inlet/outlet speed of air going in/out of our mouth during inhalation/exhalation
During inhalation, your alveoli expand, creating a pressure difference between the atmosphereic pressure and our lung sacks and therefore air will flow into the repspiratory airways.
I am trying to ...
1
vote
1answer
29 views
Does difference in expected life duration between men and women have biological nature?
It is known that men in most countries live less than women. I wonder whether it is due to different life conditions or because male and female organisms differ?
For example, I heard that ...
3
votes
1answer
49 views
What causes Acne?
What exactly is going on biologically at the molecular level with acne and causes breakouts? Hormonally, there is a lot going on but I'm curious about what is going on chemically.
6
votes
2answers
209 views
Can positive and negative blood type of a couple lead to miscarriage?
I want to know can $+ve$ and $-ve$ blood group of a couple could be a cause of miscarriage in pregnancy?
7
votes
1answer
323 views
What is the composition of human feces?
Are there any studies or general information on the composition of human feces?
I'd specifically like to know the percentage of carbohydrates and amino acids relative to the amount that was ingested ...
16
votes
1answer
373 views
Is kissing a natural human activity?
The word natural here is meant in contrast to it being a sociological construct.
Is kissing in all its forms something natural for humans? Is it instinctively erotic? Or is it just a conventional ...
4
votes
2answers
76 views
What is the purpose of the adrenal medulla?
The adrenal medulla is less of a 'real' endocrine organ like the others in the endocrine system and much more an extension of the sympathetic nervous system. In fact, its chromaffin cells are modified ...
5
votes
1answer
51 views
Is the eyes' movement discrete?
When tired and it was dark, I noticed that if I focused on a dim light source and moved my eyes fairly rapidly sideways, the resulting images that lingered for a short while were not smoothly blurred ...
2
votes
1answer
43 views
How much gas is exchanged in one human breath?
When we breathe, our lungs absorb a portion of the oxygen in the air, and replace it with some amount of carbon dioxide and water vapor. Typically, how much $O_2$ (in grams, milliliters, or moles for ...
5
votes
2answers
75 views
Is warmth/temperature sensed linearly or on a different scale?
I understand that the atmospheric temperature is sensed relative to external body temperature. However, is the sensation of warmth registered linearly, or is it on a logarithmic scale, similar to ...
1
vote
0answers
19 views
Is there an entry-level circadian model of serotonin, ghrelin, dopamine and the sense of well being?
I've long been interested in circadian rhythms and recently came across a variety of articles that appear to indicate that the following neurotransmitters, transferases and hormones are connected. ...
1
vote
0answers
33 views
Why do people feel extreme cold at different temperatures compared to other people of same body structure?
I have seen some people shivering in the room temperature of 18°C while others of similar body structure do not feel that much amount of cold.
Of course the clothing of both people is similar if ...
4
votes
0answers
50 views
Functionality of vitamin A, Bx, C, D, E, K as used in cosmetics for the skin?
I was wondering if someone can compare the functionality of vitamin A, Bx (x means numbers, such as 1, 2, 3, ...), C, D, E, K in the skin? They are used in cosmetics but what is their actual effect?
...
4
votes
1answer
44 views
Are serotonin levels in humans affected by light?
I'm reading this Wikipedia article on light therapy and noticed a peculiar statement:
The production of the hormone melatonin, a sleep regulator, is
inhibited by light and permitted by darkness ...
2
votes
1answer
27 views
2
votes
0answers
46 views
Can frequent ultrasound diagnostics be harmful?
Are there any short or long term effects apparent in tissues if a zone (or the whole) of human body is scanned with ultrasonic waves often?
5
votes
2answers
285 views
Why can't you taste food when you have a cold?
It is a common observation that food is tasteless when we have a cold. Why is that so?
What is the cause of inability to taste when we have a cold? Are the nose and ability to taste connected?
2
votes
1answer
57 views
Are humans hardwired to continue gathering resources after the costs outweigh the benefits?
An animal will stop foraging in a berry bush if the perceived cost of searching for berries remaining is greater than the cost of finding another bush which isn't as picked over. People do the same ...
1
vote
0answers
13 views
What are studies linking dietary choices over life with probability of reaching higher ages?
Are there big studies that link diet and lifestyle choices with the probability of reaching a certain age? What are their conclusions?
-2
votes
1answer
33 views
Good place to ask health based questions? [closed]
I like the development of biology.stackexchange.com, but it is still in an early stage and far from perfection. While we develop it further, could you guys help me finding places to ask questions ...
6
votes
3answers
79 views
How to map the Gene name to its Gene Symbol?
I am learning in Gene data lately so I apologize for the silly questions in advance. I read a paper for a cancer on human which found some important genes. For example, the paper listed one of genes ...
13
votes
2answers
241 views
How is temperature sensed?
Can anyone summarize the mechanism by which when an object of a given temperature is placed in contact with, say, the skin on a human fingertip, the average speed of the particles of the object is ...
10
votes
3answers
255 views
Where does the 'C' in exhaled CO2 mostly come from?
When a human being exhales $CO_2$, what is, by the numbers, the main source of carbon atoms exiting the body in this way? I mean what class of cells, or which tissues are the biggest on a pie chart of ...
1
vote
0answers
95 views
Can dry air make a person more prone to catching a cold?
I'm interested if there is a correlation between room air humidity and risk of catching a cold.
3
votes
2answers
95 views
Can children restore brain cells?
By "children" I mean young people at the age of 10 or lower.
I know that the adult brain cannot restore brain cells, but what about children? I mean, the brain must develop from a few cells to a 90 ...
6
votes
3answers
1k views
Can a human smell through the ears?
The title does, prima facie, appear absurd.
Performing a swallowing action whilst pinching the nostrils shut gives the impression of listening through a bucket filled with water around the head; ...
16
votes
2answers
15k views
What's the maximum and minimum temperature a human can survive?
This is a question that has been in my mind since I was a kid. I'm not a doctor, nor even a biology student, just a curious person. What is the minimum and maximum temperature a human body can stand ...
8
votes
2answers
205 views
How much weight/volume do microbes occupy within the human body?
Microorganisms constitute the bulk of all the biomass on Earth. I weighed myself yesterday, and wondered how much less I would weigh if I were completely free of bacteria and microbes, inside and out. ...
8
votes
2answers
198 views
Do memories have mass?
If it were possible to live forever, would our brains grow infinitely with the number of memories that we store? Or would we remove old memories as we create new ones?
3
votes
2answers
101 views
Ultrasound during pregnancy
In a hospital I can see a long queue of pregnant women waiting for their turn for ultrasound. Is it safe to go through the ultrasound during pregnancy, especially during last few weeks?
Is ...
6
votes
1answer
338 views
Why do vaccines cause your arm to hurt?
When you get a shot for a vaccine (for example, the annual flu vaccine), the nurse frequently indicates that your arm will ache for a day or two, maybe more. This ache is typically not just a pain ...
7
votes
2answers
255 views
Is nicotine toxic to humans?
More specifically, is nicotine in the concentrations that smokers receive when smoking cigarettes toxic? I know that in great enough concentrations it can be toxic (but then, so can just about ...
6
votes
1answer
72 views
How does the body measure dehydration?
What, physically, does the body do to measure it? I assume it's measured by how how turgid or plasmolysed certain 'sample cells' are, or water concentration in the blood,
What is the way they use to ...
