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.
526
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How could prehistoric humans survive without trimming their hair?
It is known that human hair, especially the hair on the head, can grow very long. This hinders the vision and seems to become a disadvantage to humans, especially when they are hunting.
I saw this ...
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0answers
35 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 ...
0
votes
0answers
20 views
Brain centers vs areas (and how they relate to nuclei)
I'm looking for a reputable source that can provide succinct definitions differentiating the following terms in the central nervous system (CNS; particularly in the brain):
Area
Center
Nucleus
...
2
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0answers
52 views
What determines walking direction in humans?
I've wondered about this for a while, without being able to come up with an answer.
Is there a body part that single-handedly determines the direction we're walking in? Is it a group of body parts ...
-4
votes
1answer
44 views
Can a person survive without platlets in the bloodstream? [closed]
Can a person survive without platlets or thrombocytes in the bloodstream, if I guarentee that the person is isolated and won't injure?
Any help will be appreciated. Thank you!
0
votes
1answer
38 views
What type of epithelium are the pancreatic Islets of Langerhans?
The human pancreas contains exocrine acinus cells (simple cuboidal epithelium) and Islets of Langerhans. Despite looking online I cannot identify what type of epithelium the Islets of Langerhans ...
0
votes
3answers
85 views
Why aren't the twin organs like both the eyes, ears, hands and legs lying both sides of a human body identical?
Both the eyes are not identical in geometrical shape and size i.e. physical appearances of both the eyes of a person are different from each other. The same difference is observable in both the hands, ...
3
votes
0answers
26 views
Are the foramina of Magendie and Luschka genuine defects of the ependymal epithelium?
Question:
Are the foramen Magendie (or the median aperture) and the two foramina Luschka (or the lateral apertures) genuine defects of the ependymal epithelium? So the ventricular lumen truly ...
0
votes
1answer
44 views
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-...
1
vote
2answers
26 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
votes
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 ...
0
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0answers
53 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 ...
1
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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 ...
1
vote
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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0answers
33 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
50 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?
0
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0answers
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 ...
0
votes
1answer
77 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 ...
0
votes
0answers
34 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 ...
14
votes
1answer
124 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&...
0
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0answers
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?
1
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0answers
18 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
vote
1answer
39 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
vote
1answer
27 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
votes
0answers
29 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
vote
0answers
46 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 ...
0
votes
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
vote
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
votes
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
54 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
199 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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votes
2answers
60 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?
0
votes
1answer
60 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 ...
0
votes
0answers
48 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
votes
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
votes
2answers
68 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?
1
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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
99 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, ...
-3
votes
1answer
80 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
420 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?
1
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0answers
176 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
votes
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?
1
vote
2answers
155 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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votes
1answer
72 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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votes
1answer
75 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 ...
1
vote
0answers
68 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
votes
1answer
182 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
votes
1answer
81 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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vote
0answers
33 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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votes
1answer
90 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 ...
