Questions tagged [human-biology]
This tag is for questions about the general biological features of human beings (as opposed to the biology of non-humans).
2,381
questions
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12 views
What is the relationship of stimulants to hair loss?
I've noticed several topical hair loss products (ex: minoxidilmax) add caffeine to their recipes with the claim that "caffeine stimulates blood flow to the scalp" thereby improving hair ...
4
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1answer
132 views
What stops myosin during muscle relaxation?
I understand that when the muscle is relaxed tropomyosin blocks myosin binding sites on actin filaments thereby preventing muscle contraction. What I am concerned with however, is whether myosin ...
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116 views
What property of water explains how sweating helps the runner continue running?
My question I have to answer is: A runner picks up pace on a warm day and starts sweating profusely. What property of water explains how sweating helps the runner continue running?
The following are ...
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27 views
Has the human capacity to heal from burns evolved due to actual burns throughout human history?
I just burned myself while cooking, and it occurs to me that although this has happened countless times, my skin always heals itself rather well after burns.
In this post I make various assumptions/...
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8 views
Is the binding of androgen to androgen receptor in prostate cancer cells a requirement for the production of prostate-specific antigen?
The binding of androgen to the androgen receptor results in the transcription of androgen-regulated genes, which signals the proliferation of prostate cancer cells. This process also produces prostate-...
15
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1answer
3k views
Why do diseases in the tap water of developing countries affect people from developed countries more?
My siblings and I went abroad to a country that doesn't have drinkable tap water, but we did not know this at the time as the people who lived there used to drink it all the time with no issues.
One ...
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19 views
How do myosins cause myofibrils to be shortened?
I know that it is the binding and tilting of myosins on actins that cause the sarcomere to be shortened. But I am a little bit confused about the details. The structure of a sarcomere is made of ...
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1answer
62 views
Why is the food we consume right from birth not immunogenic to elicit an immune response? [closed]
Excluding the hypersensitive reactions which are individual specific, how is food we consume considered safe by the immune system?
2
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53 views
What is the function of human Trypsin Inhibitor if trypsin is secreted in the inactive form of Trypsinogen? [closed]
I was reading about pancreatic digestive enzymes in a Textbook of Medical Physiology and I came across Trypsin Inhibitor. The text stated that:
It is important that the proteolytic enzymes of the ...
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1answer
44 views
Can we apply NGS (next generation sequencing) on DNA extracted from formalin fixed paraffin embedded tissues (FFPE)?
I'm working on the microbiome and I can only use tissues which are fixed with formalin and embedded in paraffin. Is it possible to apply NGS (next generation sequencing) on FFPE (formalin fixed ...
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3answers
267 views
If due to some reasons a small portion of our neurons die, how does our body remake them?
There are various reasons such as intake of neurotoxins, and possibly traumatic injuries, that can cause neurons to die.
After several hundreds, or thousands of our neurons die, how does our body ...
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1answer
57 views
Can a human survive without ACE2?
I guess not, but it was discovered in 2000 so I don't know if we know enough about it. Are there people without ACE2 (angiotensin converting enzyme 2)?
It seems mice can survive, but that's not a ...
2
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0answers
40 views
Does The Sympathetic Nervous System Increase or Decrease Urination?
According to my book:
Sympathetic nervous system stimulation, leads to the release of Norepinephrine(Noradrenaline), priming the body for the "Fight or Flight" response.
It is also stated ...
2
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1answer
138 views
Why does exhaled air still contain oxygen?
I am a high school student and I am a little confused in the concept of breathing:
My confusion is that, when we talk of exchange of gases we say that gases always diffuse from their high "...
0
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1answer
50 views
What is the difference between a myofibril and a myoblast? (In skeletal muscle)
I read that a muscle fibre (myofiber) is formed when myoblasts fuse.
https://teaching.ncl.ac.uk/bms/wiki/index.php/Skeletal_muscle#:~:text=The%20multinucleate%20feature%20is%20established%20in%...
2
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1answer
33 views
What is the difference between a dermatome and a sensory neurone?
I read that a dermatome is an area of skin supplied by a single spinal nerve but that this is sensory information? Why do spinal nerves supply the skin? I thought it was the other way round- sensory ...
4
votes
1answer
58 views
Do adult mammalian cochlear inner hair cells regenerate?
The consensus seems to be no, but I see conflicting evidence.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5361427/
Supernumerary human hair cells—signs of regeneration or impaired development? A ...
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0answers
24 views
What is the process of aging exactly? [closed]
Getting old
Hello community, I have been thinking about age, and I thought that aging is the reverse of how a biological system is able to fix itself over time. Actually, some species actually are ...
1
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1answer
42 views
How do organophosphates affect kidney function?
Many organophosphates, besides inhibiting acetylcholinesterase, can also permanently inhibit the enzyme neuropathy target esterase, leading to nerve damage. NTE also happens to be found in the kidneys,...
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0answers
37 views
Is a “Nerve” a cell or a tissue? [closed]
Nervous tissue includes Neurons and Glial cells. Neurons have soma and other projections (neurites) namely Axon and Dendrites. Axon or dendrites of a nerve cell covered with endoneurium
is called ...
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0answers
14 views
Does anybody have an references to share or idea onhow the tumor behaviour changes as it grows from oligometastasis to polymetastasis?
I have looked at the literature and mostly scientist discuss about how a metastatic lesion is formed. But what I am interested to learn is how does a new metastatic lesion develop when there is ...
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2answers
78 views
Why do we have to move in the cold for higher chance of survival?
To survive in the cold temperatures, a person should move as much as possible so that they do not freeze to death. But constantly moving also leads to the body becoming more and more exhausted.
Why ...
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1answer
14 views
Looking to understand the difference between (Fibroblast Growth Factor) FGF-2 and FGF-5
Non-biologist nor medically trained person here, but still nonetheless interested in the functioning of the human body, and more specifically, hair growth cycles.
I've read in several sources that FGF-...
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1answer
44 views
Can you eat more calories than the body can store?
I believe I have read that if the body takes in too many certain nutrients/vitamins, the body simply excretes them.
How does this behave with calories? If I have a daily consumption of exactly 2,000 ...
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1answer
90 views
Why do humans need pillow to sleep better? [closed]
As far as I know, no animal sleeps with a pillow/support under their heads. Why then do we need to keep a pillow?
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1answer
53 views
Is it true that recanalisation of the vas deferens, if any, tends to happen soon after a vasectomy (less than 1 year), and if so, why?
https://doi.org/10.1016/s0140-6736(00)02436-3 "How reliable is a vasectomy? Long-term follow-up of vasectomised men":
Most episodes of recanalisation are believed to happen soon
after ...
3
votes
1answer
137 views
Mammary gland development and lactation
I was reading on mammary gland development, and I found this (1):
As a girl approaches her teen years, the first visible signs of breast development begin. When the ovaries start to produce and ...
0
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0answers
75 views
Is there an animal venom to which humans are naturally resistant?
Some species, no matter how poisonous or venomous, have natural predators that can withstand the poison/venom. Does human also have something similar?
This question came to me after I spent an hour ...
2
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0answers
25 views
Constitutive Dark Skin vs Facultative Tanned Skin
Most can easily spot the difference between a tanned and dark person. But from my research, the only difference is in the size and concentration of melanin (Jablonski). But this continues to increase ...
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0answers
27 views
Staphylococcus (antibacterial soaps and Traditional Lathering soaps)
I have been working on a biology research assignment regarding the claim:
Antibacterial soaps are superior to traditional lathering soaps in
minimizing the transmission of disease
I have made a ...
0
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0answers
21 views
EM field in living organisms and tissue resonance frequency
I have two questions which I can't find enough information about, and I would be very grateful if someone could give me a lid to the answer:
As far as I know, if we accelerate charged particle it ...
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1answer
85 views
What kind of people are more likely to catch COVID-19?
It is well known that people of old age or with respiratory problems are more vulnerable by the effects of COVID-19. However, I wasn't able to find information on any similar trends on catching the ...
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0answers
74 views
Why is thoracic breathing dominant in women while abdominal breathing is dominant in men?
In human males, lateral movement of thorax constitutes 25% of breathing while abdominal movement accounts for 75% of breathing. It is exactly the opposite in the case of women.
I got this piece of ...
1
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1answer
61 views
Partial pressures of different gas in human blood and how they are calculated?
In Respiratory Physiology, we use the $P_x{O_2}$ and $P_x{CO_2}$ in blood at different regions of the peripheral circulation. From my Chemistry knowledge I know that $P_x$ of a gas in a solution is ...
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55 views
Na+ / K+ ATPase: How does it restore resting membrane potential? [duplicate]
Could not find any sources talking about this (in a clear manner). If the Na+ / K+ ATPase pumps 3 Na+ out for every 2 K+ it pumps in, thus making the cell more negative, why is the Na+ / K+ ATPase ...
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2answers
111 views
What are the physiological effects of retinal exposure to 380–400nm light?
There are two categories of sunglasses: UV380 sunglasses block all light with wavelength 380nm or lower, while UV400 sunglasses block all light with wavelength 400nm or lower.
This made me wonder, ...
2
votes
1answer
39 views
Monozygotic vs Dizygotic heteropaternal superfecundation
Update: I had a wrong assumption.
After triple checking, I now see that how ordinary monozygotic twins arise is 1 sperm and 1 ovum and then later the zygote splits up.
(1.1. and that that phil and ...
2
votes
1answer
54 views
is there a limit to how much humans can taste?
kind of a weird question, sorry, but i was wondering--is there a threshold at which our taste buds become overwhelmed? if i, say, put some supersweet compound in my mouth, would there be a point at ...
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2answers
100 views
Can we develop a virus which is amicable for us but deadly for SARS-CoV-2 and HIV?
I am not biologist and do not have special education in it etc.
It is know that in the wild, some species have their deadly enemies.
What I am suggesting is can we humans find/create virus that is ...
2
votes
1answer
204 views
Can the human eye axial length decrease?
I just have a quick question regarding the axial length of the eyeball.
I understand that the axial length of the eyeball grows up until your around 20 years of age which is why hypermetropia ...
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0answers
32 views
If calcium ions and cholesterols are found on the surface of the skin, would it be possible for Vitamin D to be synthesised on the skin?
Calcium ions are abundantly found in the extracellular space of the stratum corneum area, the top most layer of the skin (Skin Barrier and Calcium; https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5929942/...
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1answer
79 views
Why do doctors reccommend vegetable oils in high cholesterol and cardiovascular disease?
As there is high cholesterol in body why the patient need more fats and why the doctors are recommending it
Transcribed:
Vegetable oils are rich in polyunsaturated fatty acids (PUFA). The fatty acids ...
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0answers
26 views
Under which conditions is human energy consumption minimized?
Including but not limited to:
body state
consumed food composition
state of the digestive tract
diseases
wounds
sleep
coma, etc.; death excluded
environment state
temperature
light
pressure, etc.
...
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0answers
11 views
closed circulatory system and blood supply to the heart endocardium
Human has closed circulatory system. in this type of circulation of blood, the vessels are not directly contacted with the cells and feed the cells by extracellular fluid. Now, how does the blood flow ...
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15 views
Why does exposure to a smell for some time reduce the electrical response of receptor neurons in the olfactory system?
In what way does exposure to a certain smell for some time causes them to loose sensitivity and have a lesser electrical response
0
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1answer
46 views
Can twins that develop in separate sacs but share the same placenta be identical?
I have two younger non identical twin sisters. When my mum was pregnant she was told they were both in different sacs when developing but shared the same placenta.
We have done hours of research on ...
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0answers
12 views
Is faster breathing during exercise linearly more efficient?
Evolution's an amazing thing. It has this incredible ability to optimize variables, and often these optima can then be learned by people to gain insight into various biological phenomena.
In exercise, ...
7
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1answer
163 views
Why is there no herd immunity against common cold coronaviruses?
In discussions of herd immunity against SARS-CoV-2 the underlying assumption usually appears to be that the virus basically stops spreading once a sufficient percentage of the population has overcome ...
2
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0answers
26 views
Exhalation in human breath, through mouth or nose: which is most usual?
Until now I believed that breath exhalation through the mouth is common for most human beings, and this fact is implicit in several technical contexts of which I can think (sports, music, medical ...
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45 views
question regarding indirect ELISA
what are the plausible reasons as to why the HRPO-conjugated donkey anti-human immunoglobulin and the chromogen/substrate were added from the right to the left of the microtiter plate?
