Biology pertaining to humans
3
votes
2answers
83 views
What is the biological basis for a human's ability to think clearly and be aware while “fighting/competing”?
I'm interested in learning more about the biological systems or hormones or parts of the brain that affect short term (<15 minutes) ability to concentrate attention on the task and be aware of the ...
3
votes
0answers
49 views
What controls the feeling of discomfort/comfort before and after sleep?
I'm interested in which biological systems or hormones are involved in the following phenomenon:
Before sleep it may be difficult to find a comfortable position, and muscular aches and pains are more ...
6
votes
1answer
47 views
On the effect of polluted air on health. Is it more gradual, or more immediate?
I've heard time and again that living in São Paulo (a large city in Brasil) takes 1.5 years from your life expectancy. The allegation is that this happens because of air pollution.
I am just ...
4
votes
1answer
65 views
Is there a correlation between incidence of type 1 diabetes and vitiligo?
Does the data indicate that if you have one, the probability of you having the other is higher than that of someone who doesn't have the one?
1
vote
1answer
189 views
Is sperm contagious?
A person may have a cold or any other disease that is an airborne-infection.
Is their sperm also contagious? Should the person take any precautions?
8
votes
1answer
120 views
A timeline of the odds for survival for fertilized eggs and fetuses
I'm looking for data to build a timeline of the odds for survival of a fertilized egg, i.e.,
What are the odds it'll last a week?
What are the odds it'll last a month?
2 months?
(and so on ...
6
votes
2answers
318 views
If body temperature is 37°C (98.6°F), why are most people more comfortable at around 21°C (70°F)?
It may be different for other people, but for me, anything above 32°C (90°F) is very uncomfortable, and my body is inclined to seek cooler temperatures. But I would think that at 32°C, the body would ...
2
votes
0answers
41 views
Are there any situations in which phenylephrine is preferred to pseudoephedrine?
In the mid 2000s in the US, due to issues of drug enforcement, pseudoephedrine containing medications were brought behind the pharmacy counter and in most cases require ID, and phenylephrine was ...
10
votes
1answer
104 views
Does stress physically age our body?
Going by the assumption that stress eventually triggers a flight/fight response, and the subsequent realization that flight/fight puts the body in a system of readiness to use it's available resources ...
4
votes
0answers
102 views
How do the pharmacodynamics of the NSAIDs differ and are there “resistant” COX phenotypes?
I know that the non-steroidal anti-inflammatory drugs (e.g., aspirin, ibuprofen, naproxen) affect the enzymes cyclooxygenase (types I and II).
Is there any difference in the degree to which these ...
0
votes
0answers
72 views
If you had no water supply, is there enough free water in urine to sustain hydration? [closed]
You are in a place where there are no water. And you drink your last water, so you will urinate.
If this were the only available liquid to you:
Is there a limit to the extent to which your kidneys ...
3
votes
1answer
68 views
Predictable microchimerism
I read in New Scientist recently that microchimerism occurs between previously born siblings and grandparents, not just the mother.
Do we know which parts of the genome are likely to be transferred? ...
2
votes
1answer
352 views
What is the “lifecycle” of an average eschar and what types of cells are involved in each stage?
(after some deliberation in the comments, I've decided to make the question more general)
An eschar or "dry scab" often forms at a site of injury over a large cut or sore.
It seems as though the ...
3
votes
1answer
60 views
What are possible health risks to women having large numbers of children?
What is the possible health issue the women would face in this record?
The record for most children born to a single couple belongs to the
first wife of Feodor Vassilyev of Russia. In 27 ...
11
votes
1answer
297 views
Are human bodies programmed to die?
Following from this question: What is the evolutionary advantage of death?:
Is there any evidence that human bodies have systemic self-destruction built into their developmental program? I'm not ...
5
votes
2answers
207 views
What is the relationship between migraines and histamine?
A family member suffers from migraines so I have been reading a little around the subject.
There seem to be any number of "triggers", but I have seen mention several times of the role of histamine ...
5
votes
1answer
140 views
Total amount of CO2 / Oxygen in Bloodstream in Humans
How much carbon dioxide and oxygen from/for respiration are in the bloodstream at any one time? (mass per litre of blood or similar)
And would there be much more aside from the blood in tissue, e.g. ...
2
votes
1answer
969 views
Why do we sweat after drinking water and running?
Why do we sweat after running?
Also we sweat sometime after drinking lots of water. Why it is so?
Can someone please enlighten me in this regard?
8
votes
1answer
180 views
Why does hair turn grey or white, and why does it happen later for some?
The question is pretty simple: what is happening molecularly when hair turns grey or white? I would imagine that it is due to the lack of a particular compound. I'm also interested in why some ...
1
vote
0answers
27 views
Can progerin formation be triggered explicitly?
Corollary to my question - Could inhibition of progerin formation slow the rate at which a body ages?
Is it possible to activate/trigger progerin formation explicitly? Say, by some hormonal/chemical ...
1
vote
2answers
205 views
Shouldn't evolution have taken care of baldness already?
It is my understanding that the hair on the head is there to protect us from sunburn. I've never seen a bald animal, so isn't evolution in charge of addressing these type of things?
How is it that ...
-1
votes
1answer
211 views
Are there examples of the green beard effect in humans?
Green-beard effects are genes that:
Produce an effect that can be detected
Produce preference to others with the same effect
Are there any examples of this in humans?
4
votes
2answers
78 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 ...
4
votes
1answer
819 views
What are tendons made of specifically
From what I read on wikipedia they are made of collagen. Collagen is just a protein. Right? How is this collagen structured (I imagine like fibers). Aren't there cells in this fibers as well?
From ...
1
vote
0answers
96 views
What is the timing of information assimilation within a human brain?
A little background: I'm an avid dreamer and have great dream recall, sometimes up to 5-7 per night.
In my experience, I can sometimes trace some elements of the dream to an event that occured ...
3
votes
1answer
124 views
Could inhibition of progerin formation slow the rate at which a body ages?
According to wikipedia, progerin is activated in senescent cells. The protein itself is known to be the cause of a rare affliction 'progeria' - a disease marked by accelerated aging of the body. This ...
6
votes
2answers
86 views
Is there a consensus on whether or not race exists on a biological level?
The most recent survey I could find was from 1985 which said that 16% of biologist disagreed that "[t]here are biological races in the species Homo sapiens."
I was wondering if there's been a change ...
1
vote
2answers
227 views
How are proteins formed?
Somewhere, I have read that we need to consume proteins to make amino acids to make new proteins. What does it suggest? How do we make proteins from proteins?
4
votes
2answers
108 views
Why do people have darker skin in sunnier climates?
I don't understand why darker skin is advantageous in hotter climates. Wouldn't it absorb more of the heat? I have heard that it reduces the incidence of cancer, but I would think absorbing more ...
7
votes
2answers
1k views
What are the consequences of voluntary total celibacy?
Psychologically this might be a tough question, but in means of biology, what are the effects of total celibacy on the gonads and the nervous system concerning both man and woman in short and long ...
-3
votes
1answer
94 views
How does protein help to cure wound? [closed]
I understand that the protein helps to repair body tissues. If I increase the intake of protein, would it help to cure the wound more quickly? I would like to know how does the protein reaches the ...
-2
votes
1answer
113 views
Why does a drop of water penetrate deep sleep? [closed]
Sleeping under the stars, a breeze carrying a few drops of water came by. The sense of water drops on my arms woke me up.
I'm curious
Why does the sense of a drop of water on one's body penetrate ...
7
votes
1answer
136 views
How fast do different organs turn over cells?
It is said that the human body turns over all cells or molecules in 7 year cycles. This is not quite correct, because there are different organs changing at different speeds. My interest is what is ...
0
votes
2answers
211 views
What part of food gives the blood red color?
Roughly, what I know is, when we eat food it goes into our: Stomach > Small Intestine > Large Intestine > Rectum. So, it just moves through a digestive pipe.
What I don't understand is, what part of ...
2
votes
1answer
2k views
What is the functional difference between hemoglobin and ferritin?
I read that both hemoglobin and ferritin are for storing iron in the body. So, what is the difference between them in terms of storing/binding iron?
0
votes
0answers
21 views
Does the brain always use the same amount of energy? [duplicate]
Possible Duplicate:
How does brain energy consumption depend on mental activity?
Does the amount of energy that the human brain uses as a whole changes based on the whether an individual ...
19
votes
2answers
350 views
Why don't teeth glow?
Hydroxyapatite is the main component of tooth enamel. It contains phosphorus in the form of phosphates, pyrophosphates etc. that are found to exhibit the the property of phosphorescence. But why don't ...
4
votes
1answer
234 views
Is there a relationship between efficiency of cellular metabolism and warm-blooded-ness?
My BIO 101 book states that when human cells convert glucose to ATP, the process is only approx 35% efficient, and much of the potential energy is lost as heat. However, that heat is useful to us in ...
6
votes
1answer
112 views
Understanding Membrane / Resting Potential from the perspective of ions?
From wikipedia article RESTING potential: "there is no actual measurable charge excess in either side. That occurs because the effect of charge on electrochemical potential is hugely greater than ...
7
votes
1answer
391 views
Why do we like salt?
A few friends of mine told me that salt provides zero nutritional value to us, and in fact can harm our bodies. Now, these guys are medical students, and being an engineering student myself, I decided ...
16
votes
1answer
375 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
155 views
Energy use by muscles, actual work done by muscles and more
Lately, I've started exercising in the gym and outside. I've also started to look at the details of food I eat.
Food usually has a label saying the amount of energy is inside it. For example, some ...
7
votes
1answer
181 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?
4
votes
1answer
72 views
What biological systems are affected by Vitamin B6 (or B vitamins in general)?
B vitamins and particularly the B6 vitamin appears to the one of the main ingredients in energy drinks.
There has been anecdotal evidence from people interested in dreaming that ingestion of vitamin ...
0
votes
0answers
21 views
Needle like sensation [duplicate]
Possible Duplicate:
What actually happens when my leg 'falls asleep'?
When the blood flow to an body part like hands or feet gets reduced we feel a sensation of numbness followed by ...
2
votes
1answer
138 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 ...
7
votes
1answer
141 views
Why are some menstrual cycles irregular?
A friend of mine asked me this today, and I didn't know. I remember studying the menstrual cycle a few years ago, but I can't remember the details (other than it was very hormone-related), and so I ...
5
votes
1answer
966 views
Do hot drinks cool you down?
It is quite the old wives tale that drinking a hot drink cools you down. If you don't really think about it it does seem somewhat logical: increasing temperature will cause your body to try and cool ...
4
votes
1answer
95 views
Can humans shorten their sleeping patterns?
Can sleeping patterns be trained, or are they genetic? I read that a human needs to sleep at least 4 hours. Can sleeping time be reduced without having a negative impact?
2
votes
2answers
107 views
How might I break down bread into glucose in a model of the human digestive system?
I need to make a model of the digestive system. It would be really nice to actually show it in action, such as by breaking down bread into glucose or something similar. Is this feasible with a small ...
