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).
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What is the reason behind that sometimes when I see new thing I feel that I have already seen them?
I have googled it and I found that it is, because of good memory, but how it can be due to good memory as it didn't happen before. It happened to me many times, that I feel that the scene which is ...
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What is meant with “the chest wall and lungs are coupled together”?
Since the lung and chest are elastic, we can represent them with springs. Under normal conditions, they are coupled together: the “lung” springs are stretched and the “chest” springs are compressed. ...
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Why do humans have digestive system present at front and kidneys back?
Outlet of digestive system is present at back of the body but its digestive system at front.
Outlet of urinary system is present at front of the body but its system present at back.
Why do humans ...
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What did we learn with Nazi human experimentation?
Was there actually any useful knowledge gained from the Nazi experiments on human test subjects? Wikipedia cites freezing and phosphine gas reactions, but I would like to know other potential results ...
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Why does mouldy food make you sick?
Bread gets mouldy pretty quickly. My parents (both of whom are nurses) throw out a loaf of bread after a spot of mould is seen (because "if you can see one spot, it means the whole thing is covered in ...
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Why are the organs for reproduction and urinary excretion combined?
We eat food for getting energy to our body parts, and we excrete the wastes through urine, feces, and perspiration.
Why has nature combined the urinary tract with the genital system (urogenital ...
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Are the chemical constituents of human bodily fluids similar to sea water?
I have heard a comparison of human bodily fluids to sea water from various sources in the past. The most notable was a teacher who claimed, if I remember correctly, embryonic fluid is comparable in ...
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If the body continuously produces new sperm, how is there room for it?
If you never ejaculated, how is there room for the constantly generated new sperm? I mean, is there always room for more?
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Are humans the only primates being engaged in group sex?
There are quite many examples of humans being involved in group sex. I won't say it is a common thing and won't say whether it is "natural" or "cultural" (but "cultural" only means induced to majority ...
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Do we know how dangerous six-eyed sand spiders are?
The Sicariidae family contains the well-known and dangerous Loxosceles spp. (fiddle-backs, violin spiders).
The family's other two genera, Sicarius and Hexophthalma (six-eyed sand spiders) have ...
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Barr body. How does it work? [duplicate]
Barr's body is a spiral X chromosome. If I'm not mistaken, one random chromosome (a healthy woman) is inactivated in each cell. Which X chromosome is inactivated in a given cell is random. I've heard ...
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Knockout and knockdown of gene
Out of curiosity, I got this question whether knocking out (deletion) of a gene on one side and knocking down (RNAi) of the same gene on the other side will affect the cell in a similar manner or not.
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Why do cyanide and arsenic smell like almonds and garlic, respectively?
Why do humans smell arsenic as garlic or cyanide as almonds? Do both smells activate the same receptor? Is there any reason why our brain interprets these smells the same?
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Is it possible for a fire to start inside of a live human body? [closed]
Over the years, I've read about spontaneous combustion in the news, but now I am wondering if it's possible.
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Do all animal cells have lysosomes?
I know that white blood cells have lysosomes but what about other body cells? I mean, any other cell such as cells in the respiratory system.
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Will our biological bodies be changed after we’ve occupied and settled Mars? [closed]
I had this question in mind for very long time, and I could not find a clear answer on the Internet, so I was hoping that you might know the answer.
If we will bring life to planet Mars and a few ...
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Why some tissues like small intestine epithelium are able to be replaced so often, yet they are not one of the most common cancers?
My small intestine epithelium cells are replaced thousands times more than my prostate. Yet I'm much more likely of getting a prostate cancer than cancer on my intestine epithelium. Is there a known ...
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Does fasting improves immunity?
I have heard that fasting causes regeneration of memory cells(B- and T-lymphocytes) thereby improving immunity.Is this true? If yes, how?
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Can men also become only bald on their legs?
Often hair loss that primarily affects the top and front of the scalp will happen to men (and female) during aging. Male pattern hair loss is believed to be due to a combination of genetics and the ...
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Time lapse between fresh blood's exposure to air and that same blood turning darker red-brown
For investigative purposes, I'm searching for a tool that can be used as a quick visual assessment of the the length of time that blood has been exposed to air after the blood flow has stopped.. Let's ...
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Tissue fluid water potential
just a quick question. Is the tissue fluid the same water potential as the cells it surrounds? I am a bit confused because if it was lower it would cause water to leave the cell and if it was higher ...
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When and why did humans start disliking the way we naturally smell? [closed]
Like many animals, humans produce a myriad of scents from sweating, bacteria, possibly pheromones, etc. Many of these scents are used throughout the animal kingdom for mate choice, recognition of ...
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If human eyes watch an area, what's the shape of its capturing shape? Rectangular? Half spherical?
A normal camera can capture a rectangular image. If human eyes watch an area, what's the shape of the captured region? Rectangular? Half-spherical?
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Does eating beans of a mother cause flatulence on babies?
Is it true that if you eat beans it could cause flatulence on babies (when breastfeeding them)?
I can't find any research or scientific facts about that topic.
I thought the body of the mother would ...
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How does vasodilation slow blood flow?
During inflammation, cytokines and histamine cause vasodilation to increase blood flow to the inflamed area. However, it is also said that vasodilation slows blood flow which facilitates the adhesion ...
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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 ...
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Are red blood cells prokaryotic?
After searching "do antibiotics impact the immune system" I found out that antibiotics target prokaryotic cells. It all made a lot of sense thinking about all those yogurt recommendations you get ...
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If someone's arm is cut off, how does that affect blood circulation throughout their body?
Essentially what I'm asking is that if someone's arm is amputated, doesn't that cut off a significant part of their blood flow because the blood vessels that normally flowed up to the hand of the ...
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What does the concept of information mean in biology? [closed]
We use a lot of borrowed analogies from other sciences; linguistics, computational sciences but what do we really mean, mean with information in living systems?
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Are modern gene-editing techniques capable of creating genetically-superior versions of humans? [closed]
Can we alter the DNA in, say, a small-framed, low muscle mass male to those of elite bodybuilders?
Can we alter the DNA sequence that stops balding and hair loss? How about the genes responsible for ...
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Can a cancerous cell from outside cause cancer in a healthy person?
If a cancerous cell enters the body of a healthy person from someone else's blood or something, will that healthy person get cancer? In human beings.
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During starvation, does the human body do anything to prioritize which organs receive nutrients?
When food is scarce, the body slows its metabolic rate to conserve energy. Are there any other systems or processes that prioritize which organs receive nutrients?
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How are we able to selectively inflate our cheeks?
First an observation - I noticed that I can not inflate my cheeks with my mouth open. This means that inflating cheeks is not a muscle property and that only pressure of air from lungs trapped inside ...
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Is marriage with half-cousin's daughter more risky than marriage with others?
I want to know is marriage with half-cousin's girl more risky than marriage with a non-family girl?
Also I like to know if her parent are cousins(but from mother side), does it add more risk to this ...
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Why is free ribose not reduced to deoxyribose rather than the reduction occuring on ribonucleotides
I cannot understand why deoxyribonucleotides are not synthesized directly from deoxyribose, but ribonucleotides have to be synthesized first, and only then can deoxyribonucleotides be synthesized.
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How do you write genotypic and phenotypic ratios?
If two homozygous recessive parents are crossed, I know that all of the offspring will be homozygous recessive as well. Would you write the genotypic ratio as 0:0:4 then and the phenotypic as 0:4? (...
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Why green light is good for our health? [closed]
I have a knowledge that when you woke up and see green light it increases your sight power. How it does so?
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Can some colours be processed faster/more accurately than others?
Is the human visual / motor system able to track, and move in response to, objects of certain colours more quickly and reliably than for others? By more reliably, I mean with greater accuracy in ...
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why finger of hands and feet become wrinkled due to to water? [duplicate]
Mostly due to bathing or washing clothes our finger become wrinkled what was the reason behind it??
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Rod and cone photoreceptors are neurons?
i mean the photoreceptors have axon and dendrite and body cell or it is not neuron
any more . can we say outer segment of photoreceptor cell is dendrite ? of course these have body cells but i am ...
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Why do I feel nauseous at the sight of blood, despite not being afraid of it?
Every time I ask google this question, all it spits at me is info on blood phobias ^-^; basically, I've always been hugely interested in morbid stuff, but I noticed that I always feel sick when ...
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Why doesn't it feel suffocating when taking a shower? [closed]
When one walks into a bathroom where someone is (or just finished) taking a shower it is hard to breathe, because it's filled with steam, yet the person taking a shower can breathe just fine despite ...
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Does the deletion of Chromosome 20 cause immunity against prion disease?
I was reading recently about prion disease and it caught my attention that a normal prion protein is coded n chromosome 20, therefore, in order for an infectious prion protein to attack, there must be ...
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How "unique" human vagina is?
Regading penis Dixson showed that it is not really unique and complex. This argument (and there were some others) was used against the idea of human polygynandry.
But what about vaginal shape? I know ...
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Blood pressure in the blood vessels
Why do the capillaries have a lower blood pressure than the arteries even though the capillaries lumen is much narrower. Wouldn't the narrowness of the blood vessel increase the pressure? Also the ...
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difference between animal and plant durring organogenesis
i would like to ask about organogenesis of animals and the relationship with plant as we depends on it. me i do not understand why we are totally different with the plant but all of our body made ...
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Why there is no vaccine against Human Immunodeficiency Virus (HIV)?
I was informed by my teacher that this retrovirus changes its RNA, so there is not a drug which can recognize the RNA and somehow inactivates it. Are there any other reasons explaining why there isn't ...
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How can there not be purpose movement in the fetus until week 18, when a fetus can open its mouth and suck its fingers at week 11?
According to Fetal Movement
According to an overview produced by the Royal College of Physicians
of Edinburgh, purposive movement begins at about 18 weeks, gradually
replacing reflex movements
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Why is the mechanism of inheritance for this disease autosomal dominant?
An unrelated couple has a daughter and a son with the same rare condition. Neither parent has any obvious signs of the condition, but the father's mother (paternal grandmother) and her brother have ...
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What are the most efficient heat exchange sites on the human body?
Where on the body would be the best place to achieve the greatest cooling effect with a "cooling undergarment"? Concentrated over the kidneys, groin, inside the wrists, back of the neck?
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