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Questions tagged [human-anatomy]

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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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 ...
3
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1answer
104 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 ...
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2answers
3k 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? ...
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2answers
5k 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 ...
6
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1answer
311 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 ...
8
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1answer
2k views

Are males taller than females in humans?

Is there any scientific evidence that in humans males are taller than females? And if so, what is the reason that they are taller (please include genes or hormones that accounts for human growth and ...
3
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1answer
3k 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 ...
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0answers
226 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 ...
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1answer
5k 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 ...
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1answer
636 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?
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0answers
642 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 ...
2
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1answer
796 views

How fast is the patellar reflex?

I have found a lot of content on the patellar reflex, but I cannot find any studies on how fast the reflex is, from onset of stimulus to innervation of muscles. Does anyone know of either a study or ...
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1answer
241 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 ...
2
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1answer
5k 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? ...
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1answer
11k 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.
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1answer
179 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 ...
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0answers
85 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
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2answers
262 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 ...
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0answers
685 views

What factors limit a shape and size of an organ [closed]

We all know that anatomy deals with structure of human system. I am interested in knowing the factors that determine the shape and size of each organs in the body. For example, we know that kidneys ...
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3answers
369 views

Symmetry of species [duplicate]

I've got a silly question, sorry for that. I know, that we probably have no the right answer and the current answer could be "that's evolution, external conditions". I'd like to speculate, why most of ...
4
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1answer
350 views

Are there testosterone receptors in female mammary tissue?

Does female mammary tissue have receptors for testosterone hormones? Do male hormones influence female mammary glands, as female hormones influenced the male mammary tissue, such as in gynecomastia?
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1answer
5k views

Why do we have two eyes? [duplicate]

Humans, animals and birds all have two eyes. Why? In addition to why two instead of one, why aren't there more than two?
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0answers
65 views

is there a difference in meaning between the terms “bone architecture” and “bone structure”?

I'm wondering whether "bone architecture" and "bone structure" mean the same thing, or whether they refer to two different concepts. In this article - http://rheumatology.oxfordjournals.org/content/...
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0answers
73 views

Why can't men produce milk, just like women? [duplicate]

This might seem a bit weird, but why can only women produce milk? Wouldn't it be more beneficial to our species if all humans could produce it? I can't think of any reason only one gender would need ...
3
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1answer
15k views

How large is the variability in human bone thickness, and is “big boned” a real thing or not?

My girlfriend is arguing that there are "big boned" people, I read some articles that there is no such thing but she still didn't believe in me because she saw some articles too that big boned people ...
2
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1answer
4k views

Why does the kidney of a cow have lobules, why the kidney of a human hasn't any?

The kidney of a cow has lobules, while the kidney of a human hasn't any. I can't think of any reason why it would be good for a kidney to have lobules. It would be good if the kidney needed to have a ...
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1answer
227 views

How may the age of a child be estimated when required to do so, in video-graphic evidence?

How may it be possible to roughly conclude that a subject in a select piece of video-graphic evidence presented, is in fact a child, i.e. without the subject being, physically examined? Is it ...
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1answer
208 views

Which organs need to have fluid compartments in order to develop properly?

I am a student, slightly struggling with the new concept of fluid compartments. I know that there are two main types of fluid compartment, extra and intracellular fluid. I also read that most organs ...
2
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0answers
4k 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, ...
4
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1answer
172 views

Unable to identify a muscle of the anterior thorax

I was watching an YouTube Anatomy Video which goes over the major muscles of the anterior superficial thorax. There is a structure present throughout the video which goes unmentioned, and I can't seem ...
3
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1answer
822 views

Effects of HRT on transgender(M to F) physiology and athleticism.

I often heard of athletes in the Olympics who would be accussed of having an advantage because they were intersexed. Now I know transgenderism and being intersexed are not the same thing, but they ...
7
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1answer
2k views

What is the function of the human eye white?

If you have a look at the eyes of most animals, you never see the white part unless the eyes are averted. In contrast, humans always have the whites visible because the iris is quite small. The only ...
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0answers
75 views

Front versus back in animal anatomy [closed]

Throughout various species, there seems to be a clear distinction between the front and the back. The musculature of the front, when engaged, closes or curls up the body, protecting it, while the ...
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1answer
77 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 ...
3
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1answer
814 views

Why is one testicle larger than the other?

Why is one testicle generally larger in humans? Just due to asymmetric development, or is there a hypothesis as to some utility it serves? I read that the different heights may be attributed to ...
3
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1answer
140 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 ...
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0answers
98 views

How do we sneeze?

When a stimulus triggers the sneezing pathway, known as the trigenimal nerve network, how do the droplets from a sneeze get created within the nose? What affects the size of these droplets?
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0answers
166 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 ...
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2answers
2k 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 ...
3
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1answer
714 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
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1answer
373 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 ...
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1answer
3k 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. ...
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0answers
121 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 ...
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0answers
494 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 ...
5
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1answer
1k 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 ...
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1answer
1k 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
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1answer
2k 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 ...
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1answer
710 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 ...
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1answer
231 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 ...
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1answer
392 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 ...