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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2answers
51 views

Could humans choose to establish fibre digesting colonies in our guts?

Humans don't digest fibre, and nor do any animals, but some creatures have micro-organisms (bacteria, I'm guessing) in their gut which digest fibre for them. My question is, could humans take some ...
4
votes
2answers
159 views

What is atrial fibrillation? [closed]

I am wondering exactly what a-fib is (causes and symptoms). I would really appreciate having a sample of an EKG with it (because in my limited research, I have found it nearly impossible to find just ...
2
votes
1answer
41 views

Effects of having too much vitamin D?

I saw there was another question about vitamin D; however, I do not believe this is a repeat. What are some of the effects/side effects of having too much vitamin D in your body?
3
votes
1answer
141 views

Do macrophages engulf mtDNA?

Let us assume that in a human body, a mitochondrial DNA is released to extracellular environment. We know that mtDNA inheritance is solely matrilineal. So the question is, If your mitochondrial DNA ...
3
votes
1answer
86 views

Is there a hormone combination that makes humans grumpy?

Imagine a typical situation that is likely to give rise to a bad temper within an individual: a person is awoken very early in the morning by a sound of a lawn being mowed next door. Unlike expected ...
0
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0answers
53 views

What is the current scientific position on the issue of human race? [duplicate]

Race is perhaps one of the most controversial and sensitive issues in anthropology, biology, and other related fields. As a non-scientist, I've used google to probe the disparity between the positions ...
3
votes
1answer
113 views

Elevated position effect on recovery times from upper respiratory infections at rest?

In nursing school, they advice for people with upper respiratory infections to be in a slightly elevated position at the head region when sleeping. My intuition of the reason is that the lymphatic ...
2
votes
1answer
70 views

Role of Calcium and Magnesium in capacitation/acrosome reaction

During the acrosome reaction, the activation enzyme present in the sperm dissolves the corona radiata and zona pellucida enabling the sperm to reach the plasma membrane of the egg. Also calcium and ...
5
votes
1answer
321 views

Why is there no cure for Dandruff?

It looks like a simple problem, affecting almost half of the population at the post-pubertal age and of any gender and ethnicity [wikipedia]. What is so complex about finding a cure? Also, if you know ...
3
votes
1answer
136 views

Why doesn't Diabetes cause death by starvation?

The main cause for diabetes is lack of insulin in the body. Insulin is the hormone that allows body cells to absorb glucose from the blood. With out insulin, the body cells can't get glucose from the ...
7
votes
1answer
9k views

What is the normal duration of human sexual intercourse?

Wikipedia is saying: Men's typical ejaculatory latency is approximately 4–8 minutes How the researchers measured this? How did they know if the test subjects weren't suffering from premature ...
1
vote
1answer
104 views

Biology in romantic love

Hi could anyone explain the biological basis behind romantic love. What is the biological basis of falling in love?I know that serotonin and dopamine are secreted when we first fall in love. What ...
0
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1answer
86 views

How does Oedipus complex fit in the evolutionary theory? [closed]

This is somthing that really makes me curious. How is posible that trough a evolution process the best posible candidate is the one that falls in love whith his progenitor?
4
votes
1answer
1k views

How do you increase eumelanin but not pheomelanin?

Are Scientists currently looking into this?
1
vote
1answer
155 views

Trauma, blood loss and thirst

Back story. Watched an episode of Arctic Air, (season three episode six), where they are practicing and hoping to become a licensed search and rescue airline. Anyhow; two hikers gets attacked by a ...
1
vote
1answer
61 views

Could light/occasional smoking strengthen the lungs?

Here's my thought process, correct me where I'm wrong. It seems the human body has thresholds. Examples: You lift too much weight, and the muscles and tendons risk serious injury, but otherwise ...
3
votes
1answer
66 views

Why is brown fat brown?

I read in Tortora and Derrickson Anatomy and Physiology that : Another type, called brown adipose tissue obtains its darker color from a very rich blood supply , along with numerous pigmented ...
5
votes
1answer
178 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 : ...
2
votes
2answers
51 views

What are Antihistamines doing in a baby?

In his song Lullaby, Tim Minchin sings: Your nappy is dry and your tummy is full Of enough antihistamine to chill out a bull Yet still all this gringing According to Wikipedia, ...
1
vote
2answers
49 views

Why will tissue from identical twin be rejected in some cases?

From Medline Plus : Also, transplants from one identical twin to another are almost never rejected. My question : Why can a tissue from an identical twin be rejected ?
5
votes
2answers
248 views

Can a virophage potentially be used to cure a viral disease?

Wikipedia states "Virophages are satellite viruses that inhibit or impair the reproduction of the auxiliary virus." Is it theoretically possible for a virophage that doesn't hurt the human body to ...
3
votes
1answer
60 views

What happens to human dopaminergic reward system once a teenager becomes adult?

I've recently heard a podcast which explained teenage impulsivity and novelty seeking in part by "Lowering the baseline dopamine activity in the reward system" "Increase in dopaminergic reward in ...
1
vote
1answer
49 views

Any forms of pneumonia that can be caught?

I am aware of the fact that there are several different types of pneumonia. However, I am wondering if any of these types of pneumonia are contagious from person to person. Is this possible?
11
votes
3answers
307 views

How does a person get AIDS?

I am inquisitive to know about how a person contracts AIDS. Among the common masses it's still the belief that having sex with multiple partners causes the disease but that is not the case when read ...
1
vote
1answer
42 views

Neurology: spinal tract

I have had a few difficulties finding answers for the questions below. I have tried answering the first two myself; but, I am not sure they are correct or not. And I am not too sure about the third ...
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0answers
63 views

Relationship between small and large fast-twitch motor units

When large fast-twitch motor units are temporarily fatigued, non-fatigue small motor units in the same muscle are impaired for small delicate tasks. Why? When impulses from the brain comes down, the ...
3
votes
1answer
215 views

Why basement membrane thickens in diabetes mellitus?

Untreated diabetes mellitus may lead to blindness and kidney failure because the basement membrane of small blood vessels in these organs thickens due to increased production of collagen and laminin. ...
2
votes
2answers
221 views

Can human survive falling from 30,000 ft without a chute?

If someone falls 30,000 feet without a parachute; what are the chances of survival if they landed in the water?
3
votes
1answer
547 views

What is the minimum air pressure the human body can tolerate if oxygen supply is not an issue?

Disregarding hypoxia, what is the minimum air pressure that the human body can tolerate? (i.e. at what air pressure would the blood start to boil, or skin start to burst, or whatever else might ...
7
votes
1answer
566 views

Crusty eyes in the morning

Often, after waking up from a night's sleep hard, flaky, pale yellow crystals are deposited around the eyelids (which easily wash off with water). What are these? Why are they yellow? What are they ...
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votes
0answers
62 views

Width of vein in finger

I am working on my bachelors thesis, where one part of it is to find width of vein in fingertip. I use database images and extract vein patterns from it, but i have to calculate the width of vein and ...
3
votes
1answer
53 views

How much of the jejunum is bypassed during gastric bypass?

There is both long and short limb bypass surgeries. I want to know how much of the jejunum is bypassed with each procedure.
4
votes
1answer
27 views

When does exposure to an allergen increase / decrease allergy?

In immunotherapy a person is regularly exposed to an allergen to decrease the allergy. Yet apparently "repeated intranasal challenges ... induces robust allergic airway inflammation, " [0] So when ...
0
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4answers
465 views

Strictly from a biological perspective, what is the functional expectation of a human being [closed]

Just like the title says: Strictly from a biological perspective, what is the functional expectation of a human being. No religious or philosophy-based answers will be accepted, we are talking ...
6
votes
2answers
185 views

How would the human body adjust to sleep times if we were to live in a place with different day lengths?

You sleep at night and are active during the day that's how things work for humans, but theoretically if a human whose parents lived on earth were to be born in another planet resembling earth but the ...
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1answer
63 views

Effect of nerve pills and relationship to Shingles

Do nerve pills actually suppress the nervous system and how would that effect the Shingles virus which is known to activate under large amounts of stress?
3
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0answers
81 views

What is the main challenge in creating a chemical male contraceptive?

More than 50 years after hormonal contraception for women was invented, a contraceptive pill for males is still not available. With the obvious major biological differences in mind, why does it appear ...
2
votes
1answer
181 views

List of heritability estimates in humans?

Many people on this site ask questions that directly or indirectly have to do with heritability in human. Do you know a list of estimates of heritability of various traits in humans? Or could you try ...
2
votes
1answer
74 views

Average face shape

I am doing face detection application where every face detected is inside a rectangle. The rectangle always contains some background behind the face and now I need to extract as much of the face as ...
2
votes
1answer
147 views

Development of vitreous humor

I have tried reading about development of vitreous humor but it is all very confusing. When does it first developed ? Does it renew itself ? Please provide reliable sources..
2
votes
1answer
88 views

Where does the fate map of a human embryo end?

I'm confused about the fate map of a human embryo. Is it just a particular part of the embryo development or does it include everything, from the conception (germinal stage) to the day the baby is ...
5
votes
3answers
519 views

Does our eyeball increase in size as we grow?

Does the size of the eye increase as we develop from the stage the complete eye first forms to infancy and then to adulthood ?
1
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2answers
122 views

Which was the last significant event in human evolution? What's next?

At 10.000 BC (12 ka), we became the last of the Homo species on Earth. In evolutionary terms this is a very little time range to something happen, but I'm wondering anyway, in this meantime which are ...
2
votes
1answer
148 views

For emphysema, which of the respiratory volumes is effected. I have a couple of educated answers

It could be the tidal volume because it effects how a person inhales and exhales normally. It could be the residual volume and functional residual volume, because it increases its amount. Because it ...
3
votes
1answer
294 views

What is the beneficial function of IgE antibody?

Dont tell me the "function" of IgE is to cause allergy ! In whatever texts I have seen it is written that IgE is important to cause allergies but what is the beneficial function of IgE ? Why was it ...
5
votes
2answers
250 views

Is there a biological reason for spreading food intake into breakfast-lunch-dinner?

I keep hearing over an over how humans can satisfy their entire daily caloric need in one sitting at a fast food restaurant. At the same time I'm looking at the kitchen plates, cups, etc, and they ...
6
votes
1answer
148 views

Task-dependent “reversed” handedness: why use left hand for some tasks? How is it controlled by the brain?

I am right-handed. Which means that when I hammer down a nail, I hold the nail in my left hand, with which I can hold it straight and at a controlled position. This is true in situations where the ...
3
votes
1answer
49 views

Why are many anti-malaria drugs gap junction antagonists?

Why are many anti-malaria drugs gap junction antagonists? My professor recently just mentioned that many of the anti-malaria drugs block gap junctions. i am wondering if this blocking is important ...
1
vote
2answers
283 views

Does Science Say That We Should Die? [duplicate]

Excluding situations where you die from accidents, the main reason for death is -generaly- diseases. And usually it is about an organ which becomes "tired" after many years. These results are all ...
1
vote
2answers
123 views

How the lungs clear themselves?

Looking at my computer's fan I can say that a lot of dust is collected on it not less dust should be collected in the lungs, not to mention some inhaled parts of food. How the lungs clear themselves ...