This tag is for questions about the general anatomical features of human beings as opposed to the anatomy of non-human animals.

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1answer
78 views

What is the effect of reduced gravity on human height?

There has been talk recently of building a base on either the Moon or Mars. What I'm wondering is, if you are born and grow to adulthood on the Moon, where the gravity is a tenth of the Earth's, would ...
0
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0answers
12 views

Why do I wake up with morning wood? [duplicate]

According to this answer on a question about the brain, the answer implies that based on certain activities the human body is undergoing, the brain then diverts the appropriate needed resources to ...
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0answers
31 views

How do we sneeze? - Part 1

For some time I have been thinking about how we sneeze. I have divided my thoughts into two questions. My first question is when a stimuli triggers the sneezing pathway, known as the trigenimal nerve ...
0
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0answers
33 views

How much force can connective tissue withstand?

I have been studying a 3D anatomy model. Based on visual observation, it doesn't look like the bones would be able to stabilize themselves at all without the connective tissue like ligaments. In the ...
6
votes
2answers
252 views

Are there nerves in the umbilical cord?

I have always imagined that cutting the umbilical cord after birth might be painful. But I have always been confused about who would feel the pain and why. It occurred to me that the mother or the ...
2
votes
1answer
119 views

Is there a genetic reason explaining the difference of the height of male and female?

The male and female height difference seems to be around 1.08 if all cultures are counted from these stats: https://en.wikipedia.org/wiki/Human_height Can this ratio, 27/25, be explained by genetics ...
2
votes
1answer
81 views

Is blood pressure in the aorta and brachial artery the same or different?

Does the blood pressure at the root of aorta equal the blood pressure in the brachial artery? I've heard it does, but it doesn't quite seem to make sense as I'd think the blood pressure would be ...
0
votes
1answer
506 views

If a human is stranded with beer but no water, should they drink it? [duplicate]

TL;DR: At what percent (if any) will alcohol dehydrate you more/faster than drinking nothing? Let's contrive a situation for dramatic effect... A human goes out on a boat for a nice sail in the sea. ...
0
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0answers
81 views

Root etiology of non-pituitary low T4 and low TSH

Please note: I'd like to preface this question by stating that this is neither homework nor me seeking medical advice. I am simply trying to understand the biological, physiological root etiology ...
4
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0answers
133 views

Why are lips covered with specialized skin?

I found out some interesting facts while studying our lips: They are covered in glabrous skin, while most of the skin surface is hairy; The outermost layer (stratum corneum) of the skin is far ...
4
votes
1answer
224 views

What neuro-motor diseases cause the lower esophageal sphincter (LES) to malfunction?

Please note: This question is neither homework nor seeking medical advice. I'm simply asking for a factual, objective, biological explanation of the various neuro-motor diseases/illnesses that can act ...
0
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1answer
128 views

What is the “leaky valve” between the esophagus and stomach?

When someone talks about there being a "leaky valve" between the esophagus and the stomach, what is the exact biological structure they are talking about? This would be a structure that, when ...
5
votes
1answer
458 views

Why do men grow facial hair?

Ancestral facial hair. Our closest ancestors, the chimpanzee and bonobo, both grow facial hair around the mouth area. What is noteworthy is that this is the case in both males and females of the ...
11
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1answer
157 views

Unilateral damage to vagus nerve

Context: The vagus nerves supply the neck viscera, heart, lungs and gastrointestinal tract. They join around the oesophagus to form the oesophageal plexus. Question: Would damage to one vagus nerve ...
5
votes
1answer
93 views

What is the basis for the determining sex from position of adult pelvis?

I've read that a person with enough knowledge of anatomy can tell the difference between a "woman" who is a slim man that is very good with makeup and an actual woman. They usually claim to be able ...
1
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0answers
20 views

Why does a limb sting when it “falls asleep”? [duplicate]

Closely related to this question, but unanswered other than @Matthew-piziak providing a description and link that says: What is Paresthesia? Paresthesia refers to a burning or prickling sensation ...
0
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0answers
22 views

What is the permeability of proteins across the hyaloid membrane of vitreous to retina?

Does anyone know of any experimental work to test the permeability of the hyaloid membrane between the vitreous humour of the eye to the retina to proteins? Currently the largest molecule I can find ...
0
votes
1answer
108 views

What is the surface area of the vitreous humour in contact with aqueous humour?

This is a question regarding the anatomy of the human eye, however for my purposes medium sized mammals should do. I am interested in estimating the surface area of the hyaloid membrane of the ...
0
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2answers
175 views

Human Bones classification and anatomy quiz

I'm a junior Biology Student and I came across this Human Anatomy Question: In respect to the bone characteristics, mark the correct answer: A) Even bones: Palatine, Inferior jaw, Parietal. B) ...
3
votes
1answer
507 views

Do our belly buttons consist of scar tissue?

I read an interesting post on Facebook the other day saying that we all have a visible scar since birth - our belly button. This got me thinking (and research for me only found results regarding belly ...
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0answers
132 views

Which of these methods is both effective and reliable in elongate muscle and tendon for use in humans: growth factors or stem cell technology

Which method is it the most effective, but also the most reliable for elongating muscle and tendons for clinical trial; using modern growth factor technology or using modern stem cell technology? ...
0
votes
1answer
102 views

Would a human survive eating only living ants?

After reading an admittedly foolish question about 1 googol ants vs. 1000 humans, I had a question. Could a human survive solely on eating ants (common ants, not the stinging kind, or leafcutters etc.)...
2
votes
1answer
55 views

Physiology of tricuspid and bicuspid(mitral) valves

The tricuspid and bicuspid valves are atrioventricular valves. Both are valves that prevent backflow of blood pumped from the atria to the ventricles. However, the former has 3 "flaps" while the ...
2
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0answers
215 views

Skin extra sensitive to heat after burn

I just got my finger burnt (first degree burn $\Rightarrow$ I didn't even bother to bear the wound). It didn't hurt much, even when I pressed the wound. However, when exposed to heat (hot water, but ...
7
votes
0answers
113 views

What is basis of multifunctionality of “master glands” in the endocrine system?

I have just started reading about the endocrine system and I am having some difficulty understanding the basis of distribution of glands and associated hormones. I am using multifuntionality to ...
5
votes
1answer
149 views

Does the anatomy of our hand result in (computer) mouse-accuracy that varies by direction of movement?

First off, I apologize if this isn't the right stackexchange sub-site for asking thsi question. I was torn as to where I should post this question: it could plausibly belong in Biology, User ...
8
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2answers
294 views

Which part of human body sustains most pressure when standing up straight?

Let's suppose a healthy fit barefoot young adult standing comfortably on a flat solid surface. A reasonable guess is somewhere around the foot. But is it the ankle, the heel, or the Metatarsus?
10
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3answers
568 views

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 ...
2
votes
1answer
109 views

Is the golden ratio of anatomic measurements universally beneficial for sexual reproduction? [closed]

It is often claimed, in popular media, that the golden ratio (Fibonacci series) in for example some face measurements is aesthetically (and hence reproductively) attractive with respect to the humans. ...
5
votes
1answer
179 views

Do humans have skin cells that trigger oxytocin release in the brain?

I was reading an article by Montgomery on the therapeutic effect of pets (Boston Globe, January 12, 2015), and I found this quote: All animals appear to have cells directly under the skin that ...
2
votes
1answer
26 views

How many smaller muscles compose the interosseus muscle in the human hand?

When looking at Wikipedia, I read that the interosseus muscle is actually composed of 3 muscles, but on the French Wikipedia, they talk about a 4th muscle. So how many interosseus muscle components ...
3
votes
1answer
117 views

Why is it difficult to bend the waist while keeping the knees straight?

It's easy to keep your legs straight when you're standing up or laying flat on your back, but as soon as you try to sit up or bend down, you need to bend your knees as well as your waist. (Try it. ...
2
votes
1answer
425 views

What is the distance between the sciatic nerve and the colon at the closest point?

Is it possible that a full colon impinges on the sciatic nerve? Is there anything that physically separates the sciatic nerve from the colon?
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2answers
2k views

The Uniqueness of DNA Paradox

How can everyone have unique iris and fingerprints? After a certain amount of human beings have lived on earth, wouldn't it be possible to exhaust all possible combinations? The same principle ...
2
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0answers
28 views

Hypoglossal nerve location

I kind of know where the hypoglossal nerve is located when I look at the diagram but I'd like to know how far is the nerve from the skin and where is the closest area to the skin before and right ...
1
vote
1answer
110 views

Would somebody born 'reversed' (e.g. heart on their right side, etc.) be completely healthy?

By reversed I mean their body is a complete mirror image of a normal human's.
1
vote
1answer
142 views

Does the term “upper extremity” include hands?

I see on http://en.wikipedia.org/wiki/Upper_limb that the term "upper extremity" seem to include hands. However, in many hospitals, there is a "Hand & Upper Extremity Service", which would tend to ...
3
votes
1answer
35 views

Does the palate truly house the sense of taste?

Source: Your “palate” is the roof of your mouth, and by extension, your sense of taste. I was reading Etymonline's entry for palatable {adj.}, which cites and derives from palate {noun}: ... ...
0
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0answers
103 views

Does ale give less of a hangover than a lager?

I got into an argument surrounding beer type and hangover. Apparently there is a opinion that ales give you less hangover than lagers do (considering same alcohol content consumed). My understanding ...
4
votes
1answer
2k views

Does the human hand have 27 degrees of freedom?

I have counted the degrees of freedom in my hand over and over and I keep getting the number 19. Suppose each finger has 3 degrees of freedom. Then 5 * 3 = 15. The wrist can rotate around or back and ...
4
votes
1answer
246 views

How pain can stimulate the vagus nerve

I'm trying to find out why a prompt, severe, short pain is causing a stimulation of the vagus nerve. What could the physiological explanation be? Is that because the pain is triggering the ...
8
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4answers
1k views

Is there any way a human could whistle and be unable to speak?

Is there any situation anatomically, where a human could understand the speech of others perfectly, without any capabilities of speech themselves, but would retain the ability to whistle with a tune? ...
2
votes
1answer
709 views

When contracting a muscle will the muscle spindle stretch or contract?

When you contract your muscle, will your muscle spindle stretch or contract? And why? I was always under the impression that it was contracting your muscle spindle, but now I am not sure.
5
votes
2answers
282 views

Can someone who cannot talk still whistle?

Can someone who has a damaged larynx, which does not allow them to talk, still create a tune when they whistle? I know that the larynx is what allows a person to manipulate their pitch and volume, ...
5
votes
1answer
85 views

Stretching and compressing bones

The Young's modulus of elasticity when a bone is stretched is : 16×109 and when it is compressed, it is 9×109 N/m2. That means, change in length will be more if you compress a bone as compared to ...
6
votes
2answers
2k views

Why is the opposite of plantar flexion called “dorsiflexion”?

Why is the action of flexing the foot so that the toes move anteriorly/superiorly (i.e. in the direction opposite that which they move during plantar flexion) described as "dorsiflexion"? In the same ...
3
votes
1answer
597 views

What causes the line patterns in the palm of the hand?

The line patterns on the hand are unique to each individual, but what causes these lines and re they advantageous in anyway?
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0answers
26 views

how food moves in horizontal coils of small intestines [duplicate]

This is a very very basic question, and I am looking at it more from point of view of physics. The small intestine is a highly coiled structure, which means it has horizontal coils as well. I can ...
0
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1answer
1k views

How does the Pectoralis Major work when doing a bench press?

Disclaimer, I'm not a biology undergrad and I only know the basics about muscle movement. I know that doing a bench press works the chest, and specifically the Pectoralis Major because, well, I feel ...
7
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2answers
187 views

Why are there no artificial wombs yet?

If the conditions within the womb are mimicked, and proper amniotic fluid with constantly recycling nutrients is maintained, is it not possible to obtain an artificial womb? Is there anything missing? ...