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.
522
questions
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1answer
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Evolutionary selection pressure for human hair patterns?
Are there hypotheses or conjectures that postulate any selection pressures or benefits that account for the patterns of non-pubic human hair? Particularly:
Humans do not grow notable (i.e., non-...
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0answers
29 views
Does any tendon in humans receive a high amount of blood supply? Or is the property of not receiving a large blood supply a constant across tendons?
I read on https://www.physiocomestoyou.co.uk/blog/all-you-need-to-know-about-tendons/ (mirror):
[Tendons] do not have a large blood supply.
Does any tendon in the human body receive a high amount of ...
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2answers
23 views
In human anatomy / biomechanics, what is the motion called when the arm swings sideways so the elbow moves in an arc of 90 degrees?
In human anatomy / biomechanics, what is the motion called when the arm swings sideways so the elbow moves in an arc of 90 degrees?
So e.g. if a person was to elbow somebody behind them , or if ...
2
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0answers
20 views
The exact points of muscle attachment and the “equal and opposite force” that skeletal muscles apply
I've been trying to make a simple simulation of the human body executing some motions in Mathematica (the details are irrelevant), but I need to know some more information about muscles and how they ...
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0answers
29 views
What is the average foot size to height ratio? [closed]
Simply put, I am trying to find the average height to foot-size ratio. I could not find the answer on the internet without having to go through a lot of shoe-size conversions and pages that seemed to ...
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0answers
17 views
Do all tendons have either a synovial sheath (a.k.a. true sheath) or a paratenon (a.k.a. false sheath)?
I have read the following {1}:
According to their envelope, tendons can be divided into tendons within a synovial sheath (i.e., sheathed tendons) and paratenon-covered tendons.
This means that all ...
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0answers
10 views
Flexor/extensor group in lower arm and limb bud rotation
Have the flexor and extensor groups in the lower arm have rotated laterally 90° towards the humerus epicondyles independently of the rest of the lower arm? The pre-axial and post-axial veins are still ...
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0answers
32 views
What is the thinnest spot on the ilium called?
Is there a specific name for the spot on the human iliac fossa where the bone is the thinnest? (Or, is there a name for the thickness measurement of that spot, e.g. the left/right _________ is 2.1mm?)
...
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31 views
The position of the macula in comparison to the blind spot
Which is located in a higher postion? Macula or blind spot?
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1answer
44 views
Animal species anatomy [closed]
https://en.wikipedia.org/wiki/Animal
Do all animal species have two lungs and two kidneys similar to human beings?
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17 views
Is there empty space left in the skull after the second set of human teeth grow out? What happens to it? [duplicate]
Reading about teeth on this website, I came across this link and picture of a human child skull, where we can see how both sets of teeth are placed.
It made me wonder: after the second set of teeth ...
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1answer
64 views
Can a hinge joint technically allow rotatory motion?
Let's use a hinge joint and pivot joint as examples.
When talking about the difference between them in terms of movements permitted, I see that on any websites and textbooks, the term 'rotation' is ...
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0answers
32 views
Is there any ethnicity difference in average pupil size?
I have seen some articles claim African Americans have smaller average pupils than whites while Asians have larger pupils. Is it true?
link:
Y. Li, D. Huang; Pupil Size and Iris Thickness Difference ...
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0answers
80 views
Do patella bones form in people born with the inability to walk?
The patella is a sesamoid bone that typically doesn't completely from and ossify until ~3-6 years of age (e.g., Source). My long-standing understanding (supported by a claim in Saladin's college A&...
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40 views
Is the diaphragm made of two muscles?
Is there a 'crural' and 'costal' parts of the diaphragm as suggested in this paper or is it just a single muscle?
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0answers
16 views
How do Human Skin Creases Vary?
I am studying human gross anatomy in order to produce an anatomically correct CGI model of the human body. As part of this, I'm attempting to understand the different features that define the ...
1
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1answer
38 views
Why proprioceptive fibres (of CN V) have their cell bodies in mesencephalic trigeminal nucleus?
It's seen that GSA (General Somatic Afferent) fibres (of CN V) have their cell bodies in trigeminal ganglion. But the proprioceptive fibres' peripheral processes terminate at mesencephalic trigeminal ...
1
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1answer
24 views
Pectoralis muscles as push muscles vs pull muscles
Pectoralis muscles are the adductors, flexors of arm in addition to medial rotators of arm. How does this action translate in to acting as helping in push ups or in bench press?
I am having trouble ...
2
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0answers
25 views
Clarification for the anatomical terminology of the cerebellum
I've been trying to find descriptions for some of the fissures found on the inferior surface of the cerebellum, and so far the only source I've been able to find that provides an adequate description ...
1
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0answers
45 views
Phantom Limb | Is that even possible?
I am fascinated by the fact that an amputee can control their robotic arm by thinking of the actions they would normally execute when the limb was present.
The mind sends signals to the nerve endings ...
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0answers
15 views
Repartition of tendon sheaths in humans
As a medical student I have been taught that tendon sheaths are found predominantly in the wrists, hands and ankles. However, I learned recently that tenosynovitis often affect the biceps brachii. It ...
1
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0answers
15 views
Can the eye determine which type of defocus is presented to it?
I have a question regarding myopic and hyperopic defocus.
My question is, is the eye able to determine which type of defocus is presented to it and if so what mechanisms allow it to distinguish ...
16
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1answer
3k views
Why are the pulmonary vein and artery not like the rest of circulatory system?
I'm learning anatomy. What I learnt is that we have arteries that have oxygenated blood which appears red in color, and branch blood to arterioles to deliver blood to cells via capillaries from where ...
2
votes
1answer
50 views
is there a limit to how much humans can taste?
kind of a weird question, sorry, but i was wondering--is there a threshold at which our taste buds become overwhelmed? if i, say, put some supersweet compound in my mouth, would there be a point at ...
2
votes
1answer
136 views
Can the human eye axial length decrease?
I just have a quick question regarding the axial length of the eyeball.
I understand that the axial length of the eyeball grows up until your around 20 years of age which is why hypermetropia ...
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2answers
52 views
What's the difference between the terms “muscle” and “muscle organ”?
Foundational Model of Anatomy distinguishes between Muscle organ and Muscle. What's the difference between the two?
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1answer
59 views
Can the shoulder bones grow after the growth plates have fused?
Body builders have broad shoulders. If one start lifting weights after one's growth plates have fused, can one still increase the width of one's shoulders? If yes, does that mean shoulder bones can ...
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0answers
47 views
Where can I find anthropometric data for different ethnicities?
I get that this is a sensitive topic, but please trust me, the very reason I'm asking is because I want to represent a people properly.
There's a video game where peoples of different ethnic ...
0
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0answers
10 views
Why are the retina layers arranged the way they are? [duplicate]
The retina layers are arranged in such a way that light has to pass through several layers before hitting the photosensitive cells. Won't this be much better if the photosensitive cells made up the ...
-2
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2answers
66 views
If black absorbs light, then why did Africans evolve black skin? Wouldn't that make the heat worse? [duplicate]
Wouldn't it have been more adaptive to develop light skin and so reflect incoming light?
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0answers
41 views
Profile of a human foot
I am not sure if this is the right place to ask this question, so please let me know in case it is not. My question is just out of curiosity.
What is the reason for curved human foot profile?
First ...
4
votes
1answer
94 views
What is the function of epiglottis?
The last time I came across this question was when I was in high school. And the explanation I was given is that epiglottis works like a valve, it prevents foods from getting into the windpipe. Still, ...
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1answer
71 views
Why do humans have flat faces, as compared to chimps?
Apparently adult, particularly older human faces resemble infantile chimps more tham they resemble any other adult hominid.
And adult humans even have as many body hair follicles as infantile chimps. ...
8
votes
1answer
284 views
Is the 6th rib attached to 7th rib, and 7th rib to 8th?
I'm just confused between a lot of pics that draw the thoracic cage in their way. what are these white things that I've shown?
or why the 7th rib is attached to the 8th?
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0answers
125 views
Why do arteries have a small lumen? [closed]
My biology textbook says that arteries have a small lumen relative to the thickness of their walls. I understand why they need thick walls, to withstand high pressure and stretch etc. But when ...
0
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0answers
10 views
Is superior surface of bladder covered with visceral peritoneum OR parietal peritoneum?
As above. I am confused about the definitions here. Is it the case that every time the peritoneum touches an organ it becomes visceral peritoneum?
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2answers
116 views
Are “sympathetic nerves” the same as “cardiopulmonary splanchnic” nerves?
I've gathered from a number of sources (e.g., Patel (2015), Wikipedia, and here) that the sympathetic nerves leaving the sympathetic trunk to innervate the heart and lungs are called "cardiopulmonary ...
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1answer
69 views
Why is a penis an organ?
According to Wikipedia an "An organ is a group of tissues with similar functions". I don't know anything about anatomy but it doesn't seem to me that a penis can be delimited somewhere to form a "...
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1answer
63 views
How can a joint extend or flex?
The idea of a joint flexing or extending doesn't make sense to me, I can see how a leg or an arm might extend or flex but how does a joint extend or flex ?
"The hip joint is most stable when it is ...
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0answers
60 views
Why doesn't the spinal cord get thicker the further up we go?
The cervical and lumbar enlargements exist on the spinal cord as a result of the increased nerve input/output required for the arms and legs respectively.
However, I don't understand how the ...
0
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1answer
131 views
Is the human iris concave or convex?
Most drawing and 3D modeling tutorials show the iris to be concave. But all the diagrams I Googled show the iris is at best flat, otherwise even a little convex (discounting the optical distortion in ...
0
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1answer
76 views
Why is the thyroid gland in the neck?
The neck seems like an odd place for it. All other neck anatomy must interface between the head and abdomen (trachea, esophagus, circulation, spine etc).
Surprisingly I have not been able to find ...
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0answers
32 views
Origins of the body mechanics theory
In physical therapy and occasionally in sports coaching, there's often a precise description of the mechanics of what happens during the movement (which muscles are engaged, which joint moves where ...
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1answer
89 views
Is the backward positioning of photoreceptors bad design?
(Several questions have been asked about this topic but most are quite old and there has been at least one study since then that has attempted to answer this in a new way)
Since photoreceptors are ...
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1answer
88 views
Genes associated with human female breast size
What are the genes associated with female breast size and natural variation thereof in human beings?
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0answers
314 views
What are the differences between internal organs between sub-saharan Africans and Northern Europeans
Lets take as examples a typical Norwegian and a typical Nigerian.
In terms of human anatonomy the outer differences are more obvious e.g. (on average)
White skin vs dark skin
Pointy nose vs broad ...
1
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1answer
40 views
Does cartilage connect to other cartilage?
In the definition of a Ligament in Oxford states:
A short band of tough, flexible fibrous connective tissue which
connects two bones or cartilages or holds together a joint.
the wording of "two" ...
4
votes
1answer
98 views
True anatomical/physiological explanation for “metaphysis” etymology
The anatomy textbook1 I use for my students states that the prefix meta- means "between:"
The metaphyses (me-TAF-i-sez; meta = between; singular is metaphysis) are the regions between the diaphysis ...
1
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1answer
59 views
Why is there disagreement on the number of surfaces of the human heart?
I am finding that some state that there are 5 and some that say that there are 3.
For example, "Cardiology: An Integrated Approach" that was published in 2018 states that
There are 3 surfaces of ...
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0answers
20 views
What's the function of vitelline circulation in human embryo?
Why do we need a vitelline circulation if we already develop a placenta to gather all the nutrients we need?
Is it an evolutionary remain?
