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
91 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?
2
votes
1answer
134 views

Why can't people talk while inhaling?

Why do we have to exhale in order to talk? From looking on Wikipedia, it seems like it has something to do with the glottis, but I'm not clear on the mechanism that makes speech sound so different ...
3
votes
2answers
382 views

Why do humans have only two nipples?

If other animals have more than 2 nipples, then why do humans have only 2 nipples? Even my pet dog has more than 2 nipples.
2
votes
3answers
267 views

Is there a stem cell/ biogel method exist for muscle and tendon lengthening?

Is there a stem cell/ biogel method exist for muscle and tendon lengthening? It is known that height surgery is limit to six inches with two surgeries and three inches each, it is also true that ...
0
votes
1answer
995 views

What is the exact chemical composition of human body? [duplicate]

I've just watched Breaking Bad Season 01 Episode 03. In that Walter gives the chemical composition of human body. The conversation is as follows Walter White: Let's break it down. Hydrogen. What ...
6
votes
1answer
2k views

Is it biologically possible for an adult's eye color to change?

Can it be that the adult eye can change color? Specifically my question is about a unilateral color change, such that the color of one eye remains constant, while the other changes color over time. ...
0
votes
1answer
38 views

Exact location of E. coli in human body

E. coli lives in lower intestine. But exactly where can we find E. coli, and where is there none (or a really small amount) of it? I need the exact names of parts of the lower intestine where we can ...
0
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0answers
8 views

Function of Vermiform Appendix [duplicate]

Why is the Vermiform Appendix(a finger-like projection at the end of caecum of large intestine) called a vestigial organ even though it acts like a lymphoid organ?
2
votes
1answer
89 views

How small does a nanobot have to be to “swim through the brain” and access any neuron it wants to?

I read on this question What is in the space between neurons in a brain? that there is actually not much empty space in a brain. But my question is slightly different. Is there a visual demonstration ...
3
votes
1answer
75 views

Do human visual functions degenerate due to genetic factors or by external factors?

Does eyesight primarily deteriorate 'naturally' due to genetics (genomic/epigenomic factors), or due to external factors such as normal wear and tear, or disease? By normal wear and tear I include ...
2
votes
1answer
43 views

Relieving pain by massage

How come the pain in our body, primarily due to excessive physical exercises, vanishes after having a massage? What is the mechanism?
2
votes
1answer
36 views

Why is the vermis of the cerebellum associated with speech?

I've found multiple sources claiming that damage or impairment as a result of alcohol to the vermis of the cerebellum results in speech impairment. I find this a bit surprising, since the only areas I ...
18
votes
4answers
2k views

Why do we need red blood cells?

From what I know, the main function of red blood cells is hemoglobin transport. So, why do we need cells packed with hemoglobin: why can't it travel freely in the bloodstream? My own thoughts were: ...
0
votes
1answer
88 views

What's the evolutionary reason behind decussation?

A bunch of stuff in the human nervous system decussates. Optical information inputs from the eyes cross over in the optical chiasm. Multiple sensory and motor pathways cross-over before ascending the ...
0
votes
1answer
55 views

Can anyone remind me of the name for the inter-scapular space on the back?

It's one of those names which are often said not to exist, like philtrum. Thanks
3
votes
1answer
45 views

What are typical values for bone mass in humans?

I wonder what are typical bone mass values for adult males and females? And do they change significantly with workout and diet?
1
vote
0answers
53 views

Does a pregnant female body treat the fetus based on gender?

I have seen on a youtube video that the female body produces antigenes and antibodies when she is pregnant with a boy. But this behaviour is not produced when she is pregnant with a girl. These means ...
1
vote
0answers
11 views

How were the synaptic areas identified in the somatic sensation pathways?

I'm studying the somatic sensation pathways in neuro-anatomy and I was wondering what was the experimental procedure for identifying the number and location of the synapses in these pathways? ...
3
votes
1answer
177 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, ...
3
votes
2answers
85 views

What does it mean to have different “metabolism”?

We hear talk of different body types, and that it is more difficult for certain people to lose weight than others. On the other hand, when my physician recommends that I lose weight, they say that it ...
1
vote
1answer
57 views

Evolutionary support for parenting book “The happiest baby on the block”

The book by Dr Harvey Karp (MD) The Happiest Baby on the Block proposes that the duration of human gestation has evolved as a tradeoff between cranial size and development of the infant. He ...
4
votes
1answer
407 views

Why do I breathe out of BOTH nostrils?

After reading the question why do I only breathe out of one nostril I realized that breathing out of both isn't common. I have always breathed out of both, and when I get a stuffy nose, or a runny ...
142
votes
3answers
43k views

Why do I only breathe out of one nostril?

I was just sitting with my hand next to my nose and I realized that air was only coming out of the right nostril. Why is that? I would think I would use both, it seems much more efficient. Have I ...
6
votes
1answer
1k views

Chest muscle and female breast size

Do female chest size have anything to do with muscle? I know many female athlete and their average breast size is much bigger than normal female that does not tend to play sports. Do this have any ...
3
votes
2answers
447 views

Why has our nose evolved with the nostrils facing down?

For most animals, the whole bottom of their face sticks out and they have a snout with a mouth and nose at the end. But humans have a flat face and just a nose that sticks out. We used to have the ...
4
votes
2answers
691 views

What happens if a person has the right side of the body totally removed (including the brain)? [closed]

I guess humans could live without just the right lobe of the liver or the right brain. Could a person without the whole right side of body survive? The left brain controls the right side of the ...
8
votes
1answer
389 views

What happens to bones that do not heal?

I would like to know the steps the body takes to heal a broken bone and what happens if it cannot heal properly. I am not looking for advice or explanations on resting and not doing activity, I am ...
1
vote
1answer
168 views

Does a woman's G-spot actually exist? [closed]

Does a woman's G-spot actually exist? Are there any research studies? Links: G-spot (Gräfenberg spot) at Wikipedia U.S. gynaecologist says he has found the G-spot
4
votes
1answer
3k views

Difference between intervertebral and vertebral foramina

In the human spine, what is the difference between intervertebral and vertebral foramina? Is it just a matter of perspective and do they refer to the same thing or are they different?
2
votes
1answer
169 views

Is the human collarbone supposed to break?

I've read it in a book and have heard people mention it, but I can't find any documentation about it. But the point being made is this: The human collarbone acts as a shock absorber for impact on ...
5
votes
1answer
596 views

Why does the sacrum fuse together?

Everywhere I look describes how the 5 sacral vertebrae start fusing together during adolescence and are totally fused by the time you're 30 or so. But nobody seems to explain why this happens. It ...
5
votes
2answers
271 views

Where do the 31 spinal nerves start/meet?

Which part of the brain is the first place (from top to bottom) where all 31 pairs of spinal nerves (on each side) meet? Or if they all start at one place - where is that? Nominally, the beginning of ...
0
votes
1answer
574 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.
26
votes
1answer
3k views

Is humans' height ideal?

More or less we humans are around 1.70 meters tall. My question is, would it be possible to scale us? that is, is it in principle possible having humans 1 cm tall, or 10 meters tall or is there some ...
2
votes
1answer
72 views

Biology Analogy

In my book are given several paired analogies with me being asked to give reason for them. I could solve all of them except this: liver = thrifty house-keeper I mean, I do not understand why the ...
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0answers
80 views

Can human change its morphology or anatomy due to ecological changes?

According to Charles Darwin, as the surrounding environment changes, so changes the anatomy or morphology of a specific organism. But nowadays, humans have become very advanced in the technology and ...
2
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0answers
68 views

What causes headaches (biologically)? What does it mean directly? [closed]

Even though your brain can't feel pain, thingies in your head are installed to compensate for that. Once I thought your head starts to hurt when your brain is tired. I can't believe this any more. ...
2
votes
0answers
51 views

Questions regarding Scapulohumeral Rhythm

I'm actually an artist, but I wanted to ask this because it will help a lot in my figure drawings. My artistic anatomy teacher taught me about the Scapulohumeral Rhythm. He said that in during the ...
2
votes
1answer
3k views

Are Asian people shorter than Europeans?

People in different countries have different average heights. For example, Wikipedia's article on human height states that Australian men have an average height of 177.8 cm, and Australian women 163.8 ...
1
vote
1answer
72 views

Anatomy suffixes?

Here are some suffixes I want to know their meaning: -ium: trapezium (carpal bone) -ius: trapezius (column muscle) -ous: Talous and calcanous (tarsal bone) -alis: Acromialis, Ulnaris (shoulder ...
2
votes
1answer
354 views

Difference between flexion and contraction?

i asked this to my anatomy teacher and he said there is no difference but when it comes to specialy in body building when you say to flex their bicep they freeze their upper limb in order to do that ...
3
votes
0answers
123 views

Human female chest model or data representation?

I am looking for professionally used representation of female chest (I know how it sounds ;). Generally - a model comprehensive enough to effectively represent human chest, with focus on breasts. ...
3
votes
4answers
939 views

Bad Eyesight and Evolution

Why do many humans have bad eyesight, such as near-sightedness, which hampers performance in a wide variety of tasks? Shouldn't there be evolutionary pressure towards better eyesight?
1
vote
1answer
3k 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 ...
2
votes
1answer
46 views

Does digit 1 have an extensor sheath?

Extensor digitorum and extensor digiti minimi both insert into the extensor hoods of digits 2-5 (or just 5 in the case of e. digiti minimi). In every source that I can find, extensor pollicis longus ...
3
votes
1answer
138 views

What is the evolutionary cause for various finger lengths?

Why are the lengths the way they are with middle finger the longest?
2
votes
1answer
36 views

What are the criteria for determining the origin and end of muscle anatomically?

For example the pectoralis muscle starts from sternum region and ends on the acromion or coracoid process. Why you can't say that it starts acromion process and ends on the sternum?
2
votes
1answer
3k views

Function of the Auricle in heart

What is the function of the auricles (conical appendages through the atria) present in the heart? Do they have any other function than increasing the volume of blood the heart can hold?
2
votes
0answers
1k views

What is a lip? (upper lip and lower lip)

Everyone knows what a lip is but I'm asking from a technical and anatomical standpoint. Actually what we call "lip" is "vermilion" in medical terminology. But I want to ask if my understanding is ...
1
vote
1answer
52 views

Are bronchioles and alveoli covered by respiratory epithelium?

Which parts of respiratory apparatus are covered by respiratory epithelium and which are covered by other kinds of epithelium?