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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Are there certain symmetric-pair muscles that are slightly bigger and NOT due to handedness?
Ok, hear me out, I was just thinking about an article in Nature I read in the past titled "Scrotal asymmetry in man and in ancient sculpture"$^{\dagger}$ and more recently an entire medical textbook ...
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Anatomical Angle Made by the Fingers of an Extended Palm
Does the angle made by the fingers (excluding the thumb) of an extended palm (as shown in the figure below) have a name (such as the Lovibond or Cobb angle, for instance) ?
I have already checked ...
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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 ...
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Do cells in healing ligaments or tendons have deformation processes? If so, what are they?
I am trying to better understand how non-muscle tissue in the muscuoloskeletal system heals. Specifically, I am interested in how ligaments or tendons heal once torn.
I read the following text:
...
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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 ...
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Can drugs be administered through penis?
I was reading this paper on routes of drug administration and noticed that it mentioned intravaginal drug administration. It looks like this is a good way to take drugs because there are a lot of ...
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Medical terminology for asymmetrically-shaped paired body parts?
Some people have different sized feet [source], a limb that is slightly longer than the contralateral (on other side of the body) limb [source], or other instances of paired body parts being different ...
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How do duplicate brain regions (ex: left/right amygdaloid body) operate together?
I frequently hear talk about parts of the brain like "Amygdala" or "Hypothalamus", so I looked them up in an app called "essential anatomy". What I see is that there's mirror symmetry, and most of ...
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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 ...
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Changes in spongy urethra during tumescence
How does the columnar cells of spongy urethra expand during tumescence(erection of penis)?
If we assume that the urethra has the length, long enough to sustain tumescence without expansion of cells, ...
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Do any non-human species have packed abs?
The classic "six-pack abs" in humans is due to tendons stretched across the abdominal muscles and low body fat. Do any other animals have a similar arrangement of tendons that could result in visible "...
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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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Skin extra sensitive to heat after burn
I just got my finger burnt (first degree burn $\Rightarrow$ I didn't even bother to bear the wound). It didn't hurt much, even when I pressed the wound.
However, when exposed to heat (hot water, but ...
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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.
...
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Can exercise strengthen tendons and ligaments?
Is is possible to strengthen tendons using exercise to prevent injury, for example preventing shoulder dislocation?
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In endochondral bone formation, why does only hyaline cartilage get ossified to form bone?
There are three types of cartilage: hyaline, fibrous and elastic cartilage.
Fibrous cartilage does not have perichondrium...so it does not take part in ossification because perichondrium needs to ...
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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, ...
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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 ...
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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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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 ...
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ATP and Muscle Contraction
I have a question regarding how molecular interactions manifest in physical actions - such as hanging from a bar. To the best of my understanding, when it comes to the contraction of muscles, ATP is ...
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Is the tendon width determined by genetic predisposition, and if so, is genetics the sole factor?
Tendons' widths vary widely across humans. E.g.:
{1}: "the mean patellar tendon width was 26.10mm (SD = 3.31; range 18.33mm-33.33mm)"
{2}: "Size of the patellar tendon width, measured at the same ...
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How can we usually "trust a fart" not to be liquid or solid?
Jack Nicholson's character Edward Cole in the movie The Bucket List said ...and never trust a fart, and a search for Al Roker leakage White House will clear up any doubts what that's all about.
How ...
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Why doesn't peritoneal dialysate leak through the fallopian tubes?
It is my understanding that the female peritoneum does not form a closed (potential) space due to its puncture by the uterine tubes. If that is indeed the case, why is peritoneal dialysis in women not ...
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Average width of the male body
I've been looking for the average width (at widest point) of the average American male body but couldn't find it anywhere so far.
When I say "widest point", I mean that if you draw a rectangle (that ...
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Describing the location of the thalamic adhesion in simple English
I'm trying to describe the location of the thalamic adhesion as part of a personal project. I can't reference pictures, and I need to be as precise as possible without using convenient anatomical ...
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Exhaustion of skeletal muscle and ligaments
I read somewhere that while doing lifting back should be straight(means normal curve), so that erectors muscle in back do the work but it gets tired easily. Hence we form curve on our back like when ...
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Alpha-gamma co-activation
I am having trouble visualizing/grasping the necessity of alpha-gamma co-activation. My understanding is the following:
When an external load causes stretching of the sensory muscle spindles, the 1a ...
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What causes the blue color seen in baboons?
Based off of this question from Worldbuilding SE.
In that question, I talked about how the scrotum and buttocks of various animals have a blue color because of thick deposits of collagen in those ...
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Is there any evolutionary significance of downward facing nostrils in human beings?
The nostrils in apes and monkeys are almost at the front, but in humans nostrils (external nares) face downwards. Also a lot of non-primate mammals like goats have nostrils at the front.
Is it the ...
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Why does the clavicle ossify intramembraneously?
The clavicle is the only long bone which ossifies as a membrane bone. I studied this process, but I can't find the reason why it features intramembraneous ossification?
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Are differing shapes of the acromion congenital or acquired?
In the human body, the acromion is located here:
There exist different shapes of acromion, at least 3:
The frequency varies according to the acromion type:
Some clinicians consider that there exist ...
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How to contract sternocleidomastoid muscle by thought?
If I do not turn my head, how can I contract ( or tighten) the sternocleidomastoid muscle ( like we can intensely tighten muscle in limbs)?
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Does human skeletal muscle fascia grow new additional collagen in response to increases in skeletal muscle size?
For example, if a human skeletal muscle is growing repeatedly due to periodic weightlifting, does the fascia eventually respond to the increasing volume by growing more quantities of collagen or other ...
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Does the humeroradial joint move medially/laterally?
The humeroradial joint is a ball-and-socket joint that, if unrestricted, would allow for movement around all possible axes. However (as succinctly stated from Wikipedia):
the annular ligament, by ...
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Would a transparent iris serve its purpose?
The function of the iris is to regulate the aperture of the pupil. How does the iris obstruct light? Is it due to the pigment present in it? Or is it just due to the sheer presence of it?
I am doing ...
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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 ...
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Physiologically, how can stress/anxiety cause neuropathy?
According to the Mayo Clinic, stress/anxiety can cause "pins and needles" (neuropathy) sensations all over the body.
But how can this be? My understanding of the sensory pathway is that sensory ...
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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 ...
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Size of classical liver lobule across species
A classical liver lobule is made up of a central vein and the portal triads. A typical human liver weighs around 3 lbs. , while a typical bovine liver weighs around 12 lbs. I was wondering if anyone ...
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Why do humans have digestive system present at front and kidneys back?
Outlet of digestive system is present at back of the body but its digestive system at front.
Outlet of urinary system is present at front of the body but its system present at back.
Why do humans ...
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Movement of the Ribcage during movements of the Thoracic Spine
I want to find a rough relation between the angle of rotation of the thoracic spine and the corresponding segmental movements in the skeleton of the ribcage. I have come across some research which ...
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How does blood flow to and from the brain when a choke is applied to one side of the neck
In the sport of Brazilian Jiu-Jitsu and Submission wrestling there are some chokes that only target one side of the neck, meaning only one of the carotid arteries. In the context of blood flow, how is ...
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Is there any meaningful ratio between the width of a vertebra and its height and depth?
Given the location (i.e. their entry points, but not their trajectories) of two pedicle screws, we are trying to come up with a way to approximate the sagittal distance of the vertebral foramen to the ...
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Which of dB or dBA are more useful for predicting damage to hearing?
With no information about noise other than its loudness measured in decibels or in A-weighted decibels, which can be used to more accurately predict how much hearing damage may be caused?
Even though ...
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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 ...
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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
...
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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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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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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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