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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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DNA Dead skin cells

If the stratum corneum is anucleated, dead cells - how is it that we are able to get DNA from buccal cheek swabs? Are we grabbing more than just the stratum corneum with the swab (eg. the underlying ...
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2answers
763 views

Special visceral efferent

Why are special visceral efferent nerves are named as such? They are supplying motor impulses to muscles of pharyngeal arch, which are both skeletal(facial) and visceral(laryngeal) 1, so why only ...
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0answers
308 views

What are those brown scars in the eyes? [closed]

I have recently realised that one of my friends had brown scars or marks inside his eyes. He says that he doesn't know what they are and has been there since young. What could this possibly be ? Are ...
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1answer
942 views

What is the ratio of head to waist and waist to floor of the human anatomy?

I'm trying to find the ratio of upper body to lower body. That is, the ratio of the length of the waist to the head over the length of the waist to the floor. It's been harder to track down a ...
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1answer
2k views

What is head of a bone?

For most of the long bones head is the proximal end, but for metacarpals and Ulna, head is the distal end. Why are their distal ends called as heads? What's the criteria for calling an end as head ...
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1answer
655 views

Why did humans get rid of their tail in the evolution?

Most mammals seem to have tails. Even human embryos start out with a tail. But here we are with nothing but a tail bone that hurts when we trip over backwards. What is it good for? Why don't humans ...
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0answers
173 views

What are the absolute facial features which features sexual dimorphism in humans?

Apart from beard and moustache, is there any facial feature that would help to distinguish between men and women? It is said that men have square, rectangular or oblong face and women have oval,...
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1answer
23 views

How much smaller is the diffusivity of a molecule in the retina as opposed to the vitreous of the eye?

I'm interested in the diffusivity of macromolecules inside the mammalian retina, relative to the vitreous. For example is the diffusion coefficient for a macromolecule (protein, 50-150 kDa for ...
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1answer
106 views

Testosterone level in body with activites

Does ejaculation lower level of testosterone in body, Conflicting reports on internet, a firm answer would help a lot?
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2answers
5k views

Are tendons and ligaments classified under the muscular or bone system?

Are tendons and ligaments classified under muscular system or bone system? Basically they are not bones or muscles and that's why I have doubt.
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0answers
210 views

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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489 views

Do all body organs grow in proportion during the period of physical development?

It is obvious that during childhood and puberty, the human body grows uniformly or proportionally so that a child's arm length, for example, is shorter than an adult's arm length but is proportional ...
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0answers
198 views

Does the vagus nerve supply the human thoracic diaphragm?

The vagus nerve (CN X) passes through the oesophageal hiatus of the diaphragm at the vertebral level T10. But does the vagus nerve actually offer any nerve supply to the diaphragm?
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1answer
7k views

Why does the ring finger not move independently?

Why is it that we need to move little finger in order to move ring finger with it? For example, put your palm on a table and fold your middle finger inside. You won't be able to move your ring finger ...
8
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1answer
270 views

Why the smell of sweat greatly varies across the body?

Having only two types of sweat glands (eccrine, apocrine) I would expect the sweat odor "spectrum" to be very "narrow". However, the smell of sweat greatly varies between scalp, arms, armpits, groin ...
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2answers
122 views

Comprehensive biology or anatomy wordbank

I teach A&P for bio non majors. I have a special needs student whose accommodation requires a word bank for any anatomy identification questions I have on the exam. I would like to present the ...
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0answers
82 views

Limit of muscle atrophy [closed]

I read that lack of action leads to muscle atrophy , I experienced same when I had a cast for hand fracture. So how far this atrophy go, who decides minimum size of muscle due to lack of activity, for ...
9
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1answer
407 views

Can skeletal morphology change in adults?

I'm just a curious layman, so be gentle. I read around that things like the cranial1 and pelvic2 morphology change with age, but I also read seemingly contradictory information that bones are '...
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1answer
121 views

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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2answers
221 views

Did the capacity to be “knocked out” arise because it conferred an evolutionary advantage?

From first principles, it seems surprising that a blow to the head would cause unconsciousness rather than just impaired function. I've heard a lot of analogies to computers -- "Your brain has to ...
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2answers
261 views

What is a concussion?

When I was a kid and someone got a concussion, I seem to remember people telling me that it was when your brain impacts the side of your skull, accelerating fast enough to do so despite the ...
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1answer
244 views

growth limit on muscle

Is there any biological limit on muscle growth in human body, one can keep pushing body and keep growing more and more muscle but somewhere it must become diffcult for body to sustain those cells ...
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0answers
56 views

Mental Symphysis

Why dow we consider mandibular symphysis(symphysis menti) as type of Amphiarthrosis that too of symphysis variety, eventhough it lacks movement and cartilage at joint? Why don't we consider as ...
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1answer
38 views

Arteries used for inserting catheter

For catheter purpose, femoral and subclavian arteries are mostly used as starting point. Why? Are there other arteries which are used for the purpose?
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1answer
1k views

What is the name for the opening in the mouth for the nasal passages?

Is there a proper anatomical name for the opening in the soft palette where the nasal passages enter the mouth?
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39 views

Do cells in healing ligaments 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 ligaments heal once torn. I read the following text: If the muscle ...
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1answer
1k views

Do Japanese have a different pelvis position than Europeans?

I was watching a show that made the claim that European women's pelvis is tilted more forward compared to Japanese women's which places their butts higher up. Is this information accurate?
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43 views

Bone fracture cause [closed]

I had bone fracture twice in the same arm. So I had first bone fracture in right forearm with 45 degree break on two bones, after 3 months of that fracture while I was climbing a slope I fell and I ...
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0answers
402 views

Why are sutural bones more common in lambdoid suture? [closed]

Why are sutural bones (Wormian bones) are more commonly present at lambdoid suture? Is the tortuous nature of lambdoid suture a reason for that? Evidences for my claim: They(sutural bones) occur ...
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1answer
782 views

Ear ossicles a part of Skull?

Is there anything special about not considering ear ossicles as a part of skull? I could not understand the reasoning behind such classification.
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0answers
673 views

What's so special about Chassaignac tubercle?

1-How does massaging of carotid artery at chassaignac tubercle( anterior tubercle of transverse process of C6 vertebra ) can relieve the symptoms of Supraventricular Tachycardia? My attempt: I think ...
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1answer
160 views

Reference to hypothesis about breast sexual attractiveness?

Some time ago there was a hypothesis published,suggesting evolution made breasts mimic buttocks for either primitive men being attracted to women when they started to walk on two legs, or to ...
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1answer
67 views

What makes a rotator cuff tear symptomatic in humans?

The majority of rotator cuff tears is asymptomatic {1}. What makes a rotator cuff tear symptomatic or asymptomatic in humans? References: {1} Minagawa, Hiroshi, Nobuyuki Yamamoto, Hidekazu Abe, ...
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0answers
459 views

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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0answers
144 views

Significance of lip end curve

What is significance of curve at point where lips meet, how it is determined and what effects it has on attraction and other factors? For some people it is a downward curve, for others it's an upward ...
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1answer
190 views

What is the course of inter auricular line?

BACKGROUND: The interauricular line is the line connecting two auricles. I wish to know the exact route through which this line passes. I want to be sure whether it passes through the parietal ...
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2answers
650 views

Are there genetic causes underlying the difference in circumference of the upper arm and foream?

Is there any genetic reason for the difference in size between the upper arm and lower arm (i.e., the forearm)? In most women, it seems that the upper arm is larger in circumference than the forearm. ...
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0answers
194 views

Why is central tendon of diaphragm called a tendon?

Why is central tendon of diaphragm called a tendon when it does not connect diaphragm to any bone?
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1answer
1k views

What is the depression between bridge of nose and brow called?

In a human being, what is the depression often found between the bridge of the nose and the brow called?
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1answer
95 views

When is an anatomic entity named “laterale” vs. “lateralis”?

I'm trying to learn the latin names of anatomical entities and I have a hard time remembering whether it's "Os cuneiforme laterale" or "Os cuneiforme lateralis". In that case it's "laterale". But in ...
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1answer
4k views

Coracoid vs. Coronoid - Etymology/Naming Choice?

The word coracoid (e.g., coracoid process of scapula) literally means "resembling a crow/raven" or "of the form of a crow/raven." In this case, I assume, resembling the hooked characteristic of a ...
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0answers
77 views

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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4answers
866 views

Why heart beats increase when we are in a state of tension even though it is a disadvantage?

Suppose a poisonous snake bites you; this will likely cause hypertension, and it will result in your heart rate increasing dramatically. Because of the high rate of heart beats, your body will make ...
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1answer
220 views

Why all human beings not black in color?

Archaeologist & Historians strongly claiming Human beings originated from African continent, Where default color is Black for humans. Why all human beings not black in color?
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2answers
10k views

What is the function of epidermal ridges on human fingers (that produce fingerprints)?

What function is served by the epidermal or capillary ridges on human fingers, the supposedly unique impressions of which are known as fingerprints?
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2answers
145 views

Why do doctors use a new thread for each stitch?

Why do doctors use a new thread of the same kind for each stitch instead of using a single thread for the entire stitch?
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2answers
9k views

Why do we have more sweat glands in our palms?

Why is it that we have more sweat glands in areas such as the palms of our hands and the soles of our feet? I just learned that there are more there but I am curious as to why that is.
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1answer
879 views

How can we move our lips even though they don't have any bones? [closed]

How can we move our lips even though they don't have any bones? We can move everything if it is attached to the bones. Example: Legs & Arms. otherwise we can't move it.
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1answer
1k views

Do men with an African ethnic background have larger penises in comparison to men of European ethnic background? If so, why? [closed]

Do men with an African ethnic background have, on average, a larger penis than their European counterparts?
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0answers
525 views

How nasal hairs filter particles of micron size?

This book says: The larger particles (> 10 μm diameter) are filtered by hair in the nostrils If we see the anatomy of nasal hairs and its density in the nostrils then it seems that its impossible ...