Biology pertaining to humans
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 ...
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 ...
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 ...
6
votes
1answer
35 views
Is there a normal human melatonin concentration to light level curve?
I'm looking for a graph or a curve that would show the typical concentration of melatonin in blood or saliva for humans over 24 hours. It would be good to know the photoperiod for the same human as ...
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 ...
9
votes
1answer
101 views
What light intensity starts melatonin release in humans?
I'm interested in whether any studies have determined the intensity of light at eye level that starts melatonin release in humans.
I know that:
melatonin release is suppressed by blue light with ...
6
votes
3answers
80 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 ...
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.
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; ...
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 ...
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 ...
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?
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. ...
7
votes
1answer
69 views
What happens when we know that there is something that we forgot but we can't remember what it was?
I think it happens for everyone that sometimes we go to a room and forget why we went there. Is there any research or article on this?
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 ...
2
votes
1answer
38 views
Is it more likely to develop a throat-ache at night?
I have noticed that I rarely develop phlemmy throat-aches in the daytime, but often notice them after I have been sleeping. Is this a recognised phenomenon? Could it be because viruses or bacteria ...
2
votes
0answers
34 views
Do humans have chemosensors for nutrients or chemicals?
I'm reading about chemoreceptors on Wikipedia, and see that the typical ones are mentioned: taste, smell, co2. I would like to learn more about the other kinds of chemoreceptors that humans may ...
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?
...
3
votes
1answer
90 views
Do adipose cells divide in adults?
I have a dim recollection of having heard that when humans gain weight, adipose cells just get larger, rather than dividing. True?
1
vote
1answer
45 views
In a human, what non-germline cells have the highest/lowest mass?
I'm just curious which cells are largest/smallest in the human body other than sperm/ova.
3
votes
2answers
117 views
What makes urine smell acrid?
Occasionally, after someone's been, there is an awful acrid smell lying about long after them. What causes this? The food that they've eaten? Urea less dilute due to dehydration?
If it helps I've ...
6
votes
1answer
693 views
Will a bone marrow transplant change one's blood type?
Will a bone marrow transplant change one's blood type?
Or is the donor blood type matched with the person before transplant?
2
votes
3answers
139 views
Is there such thing as “half-life” of dopamine?
If a dopamine is released at T=0 and binds to receptor D2, what determines the time when the concentration of this neurotransmitter bound to the receptor reaches half of the original concentration? In ...
4
votes
1answer
93 views
Do effects of caffeine on human body change with habitual use?
I've been reading about homeostatic nature of a lot of neurobiological processes - the brain is trying to maintain a balance by desensitizing receptors, re-uptaking and breaking down ...
8
votes
4answers
1k 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
0answers
112 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, ...
4
votes
2answers
79 views
Does the brain and the body use the same energy source (glucose/ATP)?
I've heard that the brain consumes quite a lot of oxygen and energy, compared to the rest of the body. What I'm interested in is if this is the kind of energy and oxygen that the rest of the body ...
2
votes
0answers
63 views
Virucides - Herbal and otherwise, for HHV6 type virus or any inner-cell virus
Does anyone know where I can find a reliable list of virucides (not anti-virus) that can be used by humans? This virucide must be able to affect viruses that are already inside the cells. St John's ...
5
votes
1answer
56 views
Is there any biological reason for humans to rest after x days of work?
A lot of people live in a 7 day cycle, where 5 days of work are followed by 2 days of "rest". Vacations and holidays can increase the time available for resting.
Is there any biological reason for ...
3
votes
2answers
110 views
The probability of indirect human fertilization?
What is the probability of conception in situations when sperm isn't directly ejaculated into the woman's vagina, like:
The man's or the woman's hands come into contact with sperm, for example when ...
2
votes
2answers
595 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 ...
2
votes
0answers
85 views
How does fever physically work?
What is the physical mechanism that causes temperature to rise during a fever? I know that somehow the hypothalamus "orders" to increase the standard body temperature regulation, and this should ...
7
votes
1answer
354 views
Preferred Aspect Ratio for Human Eyes
Our eyes are spherical, our retina is circular, but still our eyes can see more in the horizontal direction than in vertical direction. Why is it so, why is the preferred aspect ratio not square?
...
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 ...
2
votes
1answer
38 views
PGC-1β Sod2 limiters/blockers
I'd like to block a percentage of PGC-1β or Sod2 expression. According to the following paper's figure beta-blockers inhibit some expression of PGC-1α. Are there any medicines/chemicals which safely ...
2
votes
2answers
57 views
Is there some branch of biology that deals with the entire organism?
I'm reading about various parts of the human body and brain and started to wander if there's a branch of biology that deals with the entire human? I know that there are branches various -biologies, ...
8
votes
2answers
299 views
How does sodium in one's diet affect blood pressure?
Due to high blood pressure, my doctor has recommended I go on a low-sodium diet. So, that got me wondering what it is about sodium that drives this recommendation?
What does sodium do to a body ...
3
votes
1answer
88 views
What is the molecular basis of hangovers?
Well, most of us have experienced the wonderful feeling of the dreaded hangover. How does it work exactly? I imagine it has something to do with dehydration but what are the underlying mechanisms?
...
1
vote
0answers
30 views
Does Dorsal Raphe Nuclei firing pattern change in response to voluntary breathing?
I'm reading this paper, which discusses how Serotonin may be involved in motor functions of mammals: 5-HT and motor control: a hypothesis .
The paper includes the following diagram of the Dorsal ...
1
vote
0answers
68 views
What triggers creative thought in humans?
Creativity, innovation and ideation. Is there something in the brain that makes the brain think that way, as opposed to "normal baseline". What triggers creative thought in humans?
4
votes
2answers
47 views
Is there a circadian component to hunger?
I'm wondering what produces the feeling of hunger in humans. Checking Wikipedia revealed that leptin and ghrelin are two hormones involved. I've also read that the digestive system produces its own ...
3
votes
1answer
206 views
Slow-oxidative fibres vs fast-glycotic fibres
Why do slow oxidative muscle fibres contain more mitochondria compared to fast-glycolytic muscle fibres?
4
votes
1answer
75 views
How quickly can the human heart rate rise and fall?
How quickly can the human heart rate rise and lower?
For example lets say a human heart rate is rested and is at 60BPM and that person is suddenly scared to trigger their fight or flight reaction. ...
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 ...
2
votes
0answers
18 views
How to seek information on the duration of biological entrainment processes in mammals?
This is a question that is a little bit hard to define for me. I'm interested in learning more about times of "attractor/entrainment" processes that may take place in the body/brain of mammals, and ...
3
votes
1answer
103 views
Can Naegleria fowleri enter through the eyes ( example rinsing/splashing eyes with water)
I understand that it primarily enters the body through the nose by by "feeding on the olfactory neurons in the nose" as answered here in a different question. Would the nerve cells in the eyes present ...
6
votes
2answers
756 views
Which shades/hues of color are easiest to distinguish for humans?
I'm trying to represent data graphically and am using a variation of hue/lightness to distinguish one data point from the next. I would like to use a color that would allow me to convey most ...
2
votes
1answer
60 views
Where are -HCl supplements absorbed in the human digestive system?
I see that quite a lot of drugs and dietary supplements sold in the USA have -HCl(hydrochloride) added to their name. For example pyridoxine hydrochloride for Vitamin B6. I'm interested in knowing ...
