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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3
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1answer
52 views

How are some people able to continue growing after reaching maturity?

This is technically a cross-post of a question posted last year concerning gigantism and how certain people are able to grow far past expectations after it's assumed they've reached maturity. How are ...
-3
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0answers
19 views
-5
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0answers
18 views

Is the human brain the muscle with the greatest leverage? Menu to brain [closed]

1) The brain being our best lever, muscularly, shouldn't we treat it better? 2) Diet being our best conduit to good health in general, don't we need more competition in the food market, relative to ...
2
votes
1answer
120 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 ...
4
votes
0answers
43 views

Does variation in human gut length vary predictably with diet of ancestors?

Background: Numerous online searches, textbooks and other sources seem to pin the average length of the human gut from mouth to anus (oroanal) between about 5-10m in length. To pick a reputable ...
1
vote
1answer
14 views

Accommodation mechanism. [closed]

Can anyone explain how contraction of the ciliary muscles causes relaxation of the zonules? Please explain it anatomically i.e. the attachments of ciliary muscles and its relation with the ...
2
votes
0answers
28 views

Do any non-human species have packed abs?

The classic "six-pack abs" in humans is due to tendons stretched across the abdominal muscles and low body fat. Do any other animals have a similar arrangement of tendons that could result in visible "...
3
votes
1answer
12k views

Why do we suffer abdominal pain after we get very angry or stress?

You also realize probably, when we get so much anger or high levels of stress, after some point we have terrible stomach ache, like really heavy pain. Why is that? How stress or anger can effect our ...
1
vote
1answer
27 views

How do macromolecules (large drugs) in the eye reach the bloodstream and what are the relative significances of these pathways?

I am considering the elimination pathways for antibodies (50-150 kDa) from the vitreous humour to the blood stream. My overarching question is what is the most significant route such antibodies could ...
2
votes
0answers
113 views

Cause of a extra vertebra in the human body [closed]

Most people have five vertebrae in their lumbar (lower back) region, which are named L1 to L5. However, some people possess an additional lumbar vertebra located below the L5. This extra vertebra, ...
-2
votes
1answer
740 views

If penis reconstruction from a clitoris is possible why isn't penis enlargement possible?

I don't understand why, if a penis can be reconstructed from a clitoris for sex change, surgical penis enlargement is not possible.
11
votes
1answer
158 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 ...
9
votes
1answer
15k views

What is the standard deviation of adult human heights for males and females?

The wikipedia article on human height reports mean height for many different countries by sex but it does not report standard deviations. What is the standard deviation of adult human heights within ...
1
vote
0answers
33 views

Would a transparent iris serve its purpose?

The function of the iris is to regulate the aperture of the pupil. How does the iris obstruct light? Is it due to the pigment present in it? Or is it just due to the sheer presence of it? I am doing ...
5
votes
1answer
44 views

Is the knee locking mechanism present in animals?

We study in human anatomy that when the knee is in full extension, the femur slightly medially rotates on the tibia to lock the knee joint in place. This reduces the work required to be done by the ...
6
votes
3answers
156 views

Why are the human knees and elbows bent in an opposite direction

I can assume that the hands used to be the same as legs. And they got weaken, and changed direction when human started to walk on two? Also why do the hand palms facing the body and not facing down ...
-3
votes
1answer
65 views

Is it necessary to remove a bullet from the body? [closed]

So here is the proof: William Lawis Pace lived with bullet in his head for many years & even hit 100. However, both in real life and movies, we often see doctors struggling to remove bullets ...
4
votes
1answer
163 views

Can defibrillation be done with a car battery?

Can successful defibrillation be done with a car battery? Is it POSSIBLE for this to work? Let's say you are stuck on a very remote place and something happens to someone... Moreover, can you jump ...
13
votes
3answers
5k views

What is the evolutionary reason behind the fragility of teeth?

Almost all organs in the human body have a rather large threshold within which the organ or tissue is capable of repairing itself using materials supplied by the body, whether it's made from organic ...
4
votes
1answer
8k views

Which blood vessel carries the most impure blood?

There is a question in my Biology textbook: "Which blood vessel in the human body carries most impure blood after few hours of meal." The answer is given as Renal artery. But I think the ...
10
votes
2answers
319 views

Why do we have two of some organs, but not all?

We have two eyes, but we don't have two hearts. Why do humans have two of some organs, but not all?
0
votes
1answer
100 views

What actually happens to the human body during fasting/starvation? [closed]

I recently came across a UN study which advocated that controlled fasting can be beneficial for the the human body and I am fascinated by stories of wilderness survival against the odds. It piqued ...
1
vote
2answers
855 views

What would happen if a person had the right side of their body totally removed (including the brain)? [closed]

What would happen (in reality or theoretically) if the entire right side of a human's body was removed? Could they live (aside from all the probable infections and such)? I would guess that humans ...
4
votes
1answer
194 views
0
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0answers
18 views

Why is the middle finger longer than the others? [duplicate]

Possibly it has to do with making the hand shaped more symmetrically (in a sense as a spear) when the hand is flat with the fingers closed together? Or has it to do with the length of the metacarpal ...
2
votes
1answer
258 views

Where does female ejaculate actually originate from?

It's common knowledge that it's released via the urethra, but where does it originate? If it doesn't come from a part of the clitoris, then why is the clitoral glans called the clitoral glans? How ...
4
votes
1answer
1k views

How are arms different than legs?

Ok, this is a bit of a tangent question, but it came up yesterday and I didn't know the answer: How are arms and legs defined physiologically? For example, we say humans have two arms and two legs, ...
6
votes
1answer
3k views

Why don't we have hair on palms?

We have hair all over the body except palms. What is the biological reason behind this? Thanks
0
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0answers
62 views

Why is my right hand's thumb on the left side and my left hand's thumb on the right side?

My daughter just asked this question, and I could not provide a thorough answer. My first speculation is that it allows one to manipulate an object using one' both hands simultaneously (if the thumbs ...
0
votes
0answers
30 views

If I were to flush enzymes down with a cellulose rich food, what would happen?

Lets say I were to consume an adequate concentration of cellulase and cellubiose with a cellulose rich food. Would nothing happen, would I successfully extract calories from the cellulose, or would it ...
1
vote
0answers
21 views

Hair turning back to original color [closed]

I am 86 years old and my hair has been solid gray for over 15 years. Now it is turning back to its original color. (red) I took a three week dosage of 10,000 Biotin in December. Could that cause it ...
4
votes
0answers
344 views

How do duplicate brain regions (ex: left/right amygdaloid body) operate together?

I frequently hear talk about parts of the brain like "Amygdala" or "Hypothalamus", so I looked them up in an app called "essential anatomy". What I see is that there's mirror symmetry, and most of ...
3
votes
1answer
32 views

Is curling the fingers considered digit flexion?

Is curling the fingers considered finger flexion and straightening the fingers considered finger extension? I feel like this is correct in everyday language, but I am not sure if it is correct in ...
1
vote
2answers
116 views

The alignment of fingers in our hand

I noticed that in my hand the index and middle finger are aligned in one direction and the next two fingers somewhat in the opposite direction. My question is, why are our fingers aligned in that way? ...
4
votes
2answers
151 views

Headshot = instant kill? [closed]

While whatching a film, I've been thinking about how does a headshot kill someone, and how long does it take? For example let's say you've beeing shot by a normal (police) handfired weapon - no ...
5
votes
1answer
180 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 ...
0
votes
0answers
158 views

Are Young Girls Stronger than Young Boys?

According to "common wisdom" the average man has, as a proportion of his body weight, 50% more muscle mass than the average woman. This is in addition to how the average man is several inches taller ...
1
vote
0answers
20 views

Is the amount of blood same in the pulmonary and systemic foetal circulation?

We learn that the stroke volume is the same for the right and left side of the heart. So the amount of blood in either circulations should also be the same. (is it? I myself doubt this statement. As ...
4
votes
1answer
178 views

Cross section through the right arm question

Is the largest drawn vein on first attached pictue v. brachialis or did they make a mistake and it's actually v. basilica? Picture 1: Cross section through the right arm (source: Thieme, General ...
1
vote
1answer
50 views

Anatomy of the ear canal

When you insert your finger into your ear, you hit a dead end. You can't insert your finger into the auditory canal. What's this dead end called, the medical term for it?
6
votes
3answers
3k views

3D models of adult male brain in the Blender software? Any open-sourced version for research?

I am trying to find 3D model of brains. I am particularly interested in adult-male -brains in Blender-model. I could find such 3D models of brains for sale here but because I am researching I would ...
0
votes
1answer
71 views

What is the correlation between hand and neck flexibility? [closed]

I am trying to understand this statement in the book, Mudras, Yoga in your Hands by Gertrud Hirschi: There is a direct relationship between the hands and the neck since the nerve paths run through ...
5
votes
1answer
7k views

Do human anal glands have any function?

Anal glands in all kinds of animals play a range of diverse functions - providing fat for preening feathers or waterproofing fur, generating distinct scent, even repelling predators. None of the ...
0
votes
0answers
30 views

What is the function of the Moderator band?

The moderator band in the right ventricle is a band sorts of muscle which consists of a significant branch of the AV bundle. Does it mean it delivers impulses to the anterior papillary muscle faster? ...
17
votes
3answers
473 views

Why would diffusion be faster across a non-specialised tissue?

The standard protocol for a person experiencing chest pains is to chew a 300mg aspirin tablet, the argument being that chewing rather than swallowing the tablet results in the aspirin entering the ...
0
votes
1answer
45 views

Difference between the spinal cord and vertebrae column [closed]

What is the difference between the spinal cord and the vertebrae column, they both run through from the head to the abdomen. Does any one have any idea.
1
vote
1answer
26 views

What would be “Sternum-Intermediate” distance?

I've asked this question on the English Language & Usage board, not being entirely sure whether this question is strictly medical, or just English knowledge suffices to answer. Do note I am no ...
1
vote
0answers
13 views

Does this habit present any harm? [closed]

Sometimes I am able to put one knee down on the floor, rest my weight on that knee, and then relax it in order to make the knee cap go up and "crack" the knee. I can do this with both knees, I think ...
1
vote
0answers
34 views

Atlas from human brain structures to 3D coordinates?

I would like to visualize specific human brain structures in the three dimensional space and compute specific geometric properties of these brain structures (size, centroid, etc). Therefore, I am ...
2
votes
2answers
81 views

Skull size of Homo naledi

I want to 3D print the skull of the newly discovered Homo naledi. The printing data can be found here: http://morphosource.org/index.php/Detail/MediaDetail/Show/media_id/7300 Where can I find the ...