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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10
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2answers
1k views

Why do Hot/Cold drinks taste sweeter once returning to room temperature?

Now, I know this is a very bizarre question, and I tried to find a correct exchange for this, but it might relate to biology/science as it being our taste buds and everything. I am so sorry if there ...
4
votes
1answer
85 views

What causes anorexia nervorsa?

I've heard of anorexia nervosa being a severe loss of appetite. I'm wondering what causes such disease in humans?
5
votes
1answer
2k views

What's a mouth ulcer/canker sore “made of”, and why do they develop?

Mouth ulcers are red/white rings with a crater. They are sore and last for 7-10 days. What I want to know is what they are 'made of' - i.e., what is the ring filled with, and why is the centre crater ...
4
votes
3answers
9k views

Is the human body composition real?

In Fullmetal Alchemist when Ed goes to disprove to Rose the Sun God's "miracle" to bring humans back to life by proving that science (in the form of Alchemy) can create people by saying Water (35 ...
5
votes
4answers
3k views

Is lemon water an alkalizing agent in the body?

I was recently having a discussion with someone about whether lemon water actually increases the pH of your body (by which I assume they mean the blood); their claim was that once Citric acid was ...
7
votes
1answer
88 views

Can a Turner syndrome patient develop male characteristics artificially?

From an answer to the question Can stem cells from male convert to cells of female-only organs, and vice versa? Y chromosome is the sex determining chromosome with SRY gene that determines testes ...
14
votes
1answer
14k views

What is the female equivalent of the morning erection that some men experience?

There was question about what causes "morning wood." It was answered that the erection in the morning is caused by decline of norepinephrine during REM sleep. Which in part allows to prevent ...
11
votes
1answer
262 views

What biological functions does crying serve?

Tears suddenly start flowing out of our eyes when we find our long lost friend or when someone unexpectedly decides to break up with us. Do tears really save us from harm? Or are they just the reflex ...
4
votes
1answer
126 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 ...
0
votes
0answers
12 views

Modeling a patient's parameters (SPO2, HR, BIS etc.) to their effect on the patient

I'm currently using code (C#) I wrote which creates a 3 compartment model to simulate the concentration $C_{p}$ of Propofol in blood plasma using the Schnider and Marsh pharmacokinetic models. I ...
0
votes
1answer
72 views

What actually happens to the human body during fasting/starvation? [closed]

I recently came across a UN study which advocated that controlled fasting can be beneficial for the the human body and I am fascinated by stories of wilderness survival against the odds. It piqued ...
0
votes
1answer
31 views

Why do people cut back on kilo-calories?

I am learning about specific heat in science and I learned about how the specific heat for water is called a calorie, but that is different to what is on the food label. On the food label, that ...
3
votes
3answers
415 views

At what temperature do human bones disintegrate?

I know, the human skin can get damaged as quickly as 2 seconds, when exposed to temperature above 80 Celsius. However, what about human bones, say the skull? For example, when you cook a meal, at ...
0
votes
1answer
33 views

Amino acids in human cancer cells expose dextrorotation?

I would like to know if the amino acids in the human cancer cells are dextrorotatory or levorotatory. I mean the majority of them. They expose levorotation just like the amino acids in the normal ...
2
votes
0answers
45 views

T cell sensitivity and persistence to specific bacterial proteins

Currently, the standard tests for Lyme Disease measure antibody production after exposure to a bacteria, Borrelia burgdorferi. Often, the tests are performed too soon after infection, before ...
3
votes
1answer
81 views

What is the difference between a Human Being, Homo Sapiens and a Neanderthal?

I know that the Neanderthal's are a branch of the Human Being but how do all three relate to each other or more specifically what is the difference?
1
vote
0answers
58 views

Why are sarcomas rare compared to carcinomas?

A sarcoma (from the Greek σάρξ sarx meaning "flesh") is a cancer that arises from transformed cells of mesenchymal origin. Thus, malignant tumors made of cancellous bone, cartilage, fat, muscle, ...
7
votes
1answer
9k 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 ...
-2
votes
2answers
53 views

Can all elements be found in our body? [closed]

There are many Natural occurring atomic elements. Can they all be found in the human body?
1
vote
2answers
837 views

What would happen if a person had the right side of their body totally removed (including the brain)? [closed]

What would happen (in reality or theoretically) if the entire right side of a human's body was removed? Could they live (aside from all the probable infections and such)? I would guess that humans ...
2
votes
0answers
49 views

Why do people tend to stand on one leg? [closed]

I know for a fact, by observing people and from own experience (you can try it yourself while standing, but not too consciously and in a loose way) that they (like birds), while standing, tend to do ...
4
votes
1answer
191 views
1
vote
2answers
14 views

Do Class A biosolids count as organic fertiliser?

Does Human Waste, which has been treated at least twice to remove pathogens & remove stink, still count as organic despite it passing the EPA's class A standard? If so, does this mean that none-...
0
votes
1answer
23 views

Cell division - meiosis

Really confused. How many chromosomes pairs do humans have in their sex cells? How many single chromosomes do humans have in their sex cells?
1
vote
0answers
13 views

Why human hair is losing its color over time? [duplicate]

Human hair is losing its color over time, that's a known fact. I would like to know why, meaning what biological processes are involved in this? Also, is it part of the DNA somehow, i.e. the exact ...
0
votes
0answers
12 views

Is salivation decrease during sleep beneficial?

Papers [1, 2, 3] tell that a salivation decrease is not only unpleasant, but harmful for dental health. What cause that decrease? What is the reason for it and do animals have it? I guess it's a ...
18
votes
2answers
13k 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.
9
votes
2answers
2k 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 ...
2
votes
1answer
29 views

Do we know a complete list of nutrients that humans must ingest to live?

When the people who are making "nutritionally complete" foods like Soylent are developing their product, how do they know that they've covered all their bases? You need to have protein, carbohydrates, ...
12
votes
3answers
119 views

How does the brain immediately know when one's thirst has been quenched?

The question struck me the other day when I drank a glass of water. I understand that there are at least two conditions under which the brain signals thirst: extracellular thirst, when there's not ...
1
vote
0answers
43 views

Why do some men have patchy beards?

Why do some men have patchy beards? Or more specifically, why would some hair follicles lack sufficient 5-alpha reductase while others nearby don't when their genetic code is identical and they are ...
1
vote
0answers
25 views

Number of pair of chromosomes in sex cells of human [closed]

Just wondering how many pair of chromosomes in sex cells of human? How many single chromosomes in sex cells of human? Thanks for your help! It is said the chromosomes in sex cells are haploid?
9
votes
1answer
13k views

Name (and meaning of the absence) of the white semicircle at the base of the fingernail?

At the base of fingernail, there is a white semicircle (see on the first picture). But sometimes there isn't one. My questions are: what is this white semicircle on the fingernail, and what causes ...
0
votes
0answers
31 views

If your atlas is out of alignment, will the rest of your spine be out as well?

I just found out about this association called Nucca. Basically, they are a chiropractic association - their whole idea is that if your atlas is out of alignment, then the rest of your spine is also ...
1
vote
2answers
500 views

Can excessive carbonated drink consumption lead to elevated red blood cell levels?

I've recently had a blood test and the results displayed elevated levels of erythrocytes as well as hemoglobin. (As a result my hematocrit levels were also above average) At my workplace there is a ...
0
votes
0answers
22 views

peritoneal dialysis Vs Hemodialysis?

Their are basically two types of dialysis: 1.peritoneal dialysis 2.hemodialysis, My Question is Why the peritoneal dialysis needs to be carried out on everyday BUT hemodialysis is carried out on only ...
0
votes
0answers
10 views

Is there any range for Aortic Valve Gradient?

I understand aortic valve gradient is pressure on the value (measured in mmHg). What I would like to know is if there has been any research that identified a minimum and maximum pressure value as the ...
2
votes
1answer
1k views

Why does air from the nasal cavity not go into the oesophagus?

When we ingest food, the epiglottis covers the trachea and the uvula covers the nasal passage. But what happens when we breathe? Why does the air go into our trachea and not the oesophagus?
4
votes
1answer
304 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 ...
4
votes
1answer
1k views

How are arms different than legs?

Ok, this is a bit of a tangent question, but it came up yesterday and I didn't know the answer: How are arms and legs defined physiologically? For example, we say humans have two arms and two legs, ...
0
votes
2answers
98 views

What makes something food?

From my (limited) understanding, animals get energy from food by breaking chemical bonds between molecules. There's a lot of water here [citation needed], so it seems like natural selection would ...
3
votes
1answer
73 views

Why cold water results in cough [closed]

I have a pretty simple question which always kept me intriguing since childhood and I couldn't find its precise answer yet. Why do we cough by cold water. Recently I had flu and found very strange ...
1
vote
0answers
46 views

What happens to the human brain when unconscious?

What part of the brain gets affected and does it harm the brain? Thank you I just needed some extra info for a video I'm making.
3
votes
1answer
986 views

What are hot spots on human body?

Recently I have just discovered that a certain amount of the mobile phone frequency can be absorbed by human tissues. For example, this is the SAR info of iPhone 4s: Head: 1.180 W/kg 1 g Body: 0....
3
votes
0answers
42 views

What happens to the brain during sleep versus unconsciousness?

How does being unconsciousness differ from being asleep and whether it causes breaks in consciousness?
3
votes
1answer
96 views

How two genomes adopt when cell goes to recipient's body from donor's body?

We often give blood to another following the blood giving compatibility chart. Heart transplant and similar transplants also brings one's cell to another's body. My curiosity is, when a cell goes to ...
6
votes
1answer
3k views

Why don't we have hair on palms?

We have hair all over the body except palms. What is the biological reason behind this? Thanks
5
votes
1answer
397 views

Getting goosebumps at will

I can get goosebumps at will, regardless of the environment. Its mostly visible on my arms, and I can feel it on my head. It requires some level of concentration to achieve this. My questions are : ...
3
votes
2answers
133 views

Does sweat contain DNA information?

I was reading this article : Perspiration The first question which came to my mind after reading the composition of sweat was whether it contains any information about the DNA or not? I haven't had ...
3
votes
3answers
6k views

If the top epidermal layer is burned away, what is it replaced with?

If the squamous (top) layer of epidermis, or skin, is burned or damaged in another way, will it then be replaced by the next layer of below? Also, from where does the basal membrane originate? Does ...