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.
532
questions
-3
votes
0answers
40 views
Why can't we see the cell inside the eye?
As we know that the cells have organelles like nucleus and mitochondria and these organelles present everywhere even in our eye, so how come that we can’t see the cells and organelles that present in ...
-1
votes
1answer
108 views
What is the difference between the cheeks and the near parts?
Linguistically, there should be the different property or feature between cheeks and the parts right near them for us to call cheeks “cheeks.” What is the main difference between cheeks and the other ...
1
vote
1answer
54 views
Is human skull size related to brain size?
Me and my dad have a disagreement about this. He thinks that if a person had a larger skull they would naturally have a larger brain. I think that he is assuming the evolutionary trend holds on an ...
1
vote
0answers
22 views
Are there any congenital anomalies that cause a lack of epicanthic folds in a child who would normally have them?
Wikipedia lists several medical conditions associated with epicanthic folds. Mount Sinai says that epicanthic folds in a baby who would not be expected to have them is a diagnostic tool that indicates ...
0
votes
0answers
13 views
In what layers of skin are free nerve endings found?
I found online that free nerve endings are found in the epidermis and dermis, but I couldn't find information on what specific layers of the epidermis these free nerve endings are found in like the ...
-1
votes
1answer
63 views
Why can't I swallow the entire (liquid) contents of my mouth at once?
I've tested this out using water - I manage to fit a certain amount of water in my mouth, but if I try to gulp it all at once, I fail: I feel like spitting the water out (gag reflex?) There's a ...
0
votes
0answers
33 views
The location of pulmonary valve in comparison with the aortic valve
According to most transverse diagrams of heart, the pulmonary valve, in comparison to the aortic valve, angles towards the left side a little bit. Take, for instance, the pulmonary valve is more ...
1
vote
1answer
52 views
Is it possible to see some renal pyramids in a transverse section those which cannot possibly be viewed in one longitudinal section at the same time?
This is just a random image I found on Google.
It is showing that, in cross-section, several renal pyramids can be viewed. Is it so?
According to the following longitudinal section of the kidney, I ...
0
votes
0answers
29 views
What is seperating one muscle from another in body?
I have been learning about gross anatomy and have been watching a lot of dissection videos online and this question has me a bit confused. I know that the human body have about 600 muscles. I know the ...
1
vote
0answers
17 views
Cell location co-ordinates [closed]
I have just had the nails on both my big toes removed. I am much happier. But it got me to thinking, as there is no 'root structure' from which the nail grows, is there an x,y,z, type co-ordinate ...
38
votes
2answers
5k views
Why do we have two kidneys but one liver?
Both the liver and the kidneys are involved in "cleaning" our blood. But why we have one liver and two kidneys? I can just as well imagine that we have two livers and one kidney. Is this ...
0
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0answers
38 views
Does Vasa deferens produce any secretion in the Human Body?
I got this doubt while attempting the following question:
...
2
votes
0answers
24 views
Motion of Fallopian tube fimbriae
The fimbriae at the ovary end of Fallopian tubes are described as "sweeping" eggs from ovaries into the tubes:
When ovulation is about to occur, the sex hormones activate the fimbriae, ...
0
votes
0answers
34 views
Why does bicep activate during dead hang?
Hanging from a bar causes my bicep to feel much harder than when simply holding my arm straight above my head relaxed, without a bar.
This was slightly surprising to me: I used to assume that since ...
1
vote
0answers
36 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
votes
0answers
57 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
50 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
110 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
90 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
30 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
56 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
30 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
votes
0answers
131 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
vote
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
34 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?)
...
0
votes
0answers
34 views
The position of the macula in comparison to the blind spot
Which is located in a higher postion? Macula or blind spot?
-6
votes
1answer
61 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
votes
0answers
22 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
100 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
71 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
131 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
votes
0answers
41 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
vote
0answers
20 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
42 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
33 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
35 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 ...
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
115 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
320 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 ...
-1
votes
2answers
104 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
74 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 ...
-2
votes
2answers
74 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
vote
0answers
43 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
112 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
132 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
791 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
vote
0answers
226 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 ...
