Questions tagged [skin]

The skin, part of the integumentary system.

Filter by
Sorted by
Tagged with
0
votes
0answers
6 views

How does expansion of the skin via mitosis influence the density of its specialised nerve endings

I did find a reddit question Do nerves & nerve endings expand with skin or does skin expansion causes loss of nerve density where a user references the study Assessment of Epidermal Nerve Fibers: ...
19
votes
3answers
2k views

Why does UV radiation from the Sun cause skin cancer?

What is the specific mechanism makes non-ionizing UVA and UVB radiation carcinogenic? Can lower energy light, like visible light, be carcinogenic because of this mechanism, or is there some kind of ...
1
vote
0answers
70 views

Why are many skin depigmenting agents toxic to the body?

Coming from a developing country, I know many people who regularly use these creams to lighten their skin and some of them have developed liver and kidney problems as a result. I know that many ...
2
votes
1answer
490 views

Why are all human beings not black in color?

Archaeologists and historians strongly claim human beings originated from the African continent, where the default color is black for humans. Why are all human beings not black in color?
2
votes
1answer
39 views

How do humans detect temperature differentials on the skin?

I just read this question on Physics SE about how the body detects cold or warm surfaces. As someone who already understands how heat flux devices like thin film gauges and thermocouples work (by ...
1
vote
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 ...
2
votes
0answers
25 views

Constitutive Dark Skin vs Facultative Tanned Skin

Most can easily spot the difference between a tanned and dark person. But from my research, the only difference is in the size and concentration of melanin (Jablonski). But this continues to increase ...
-1
votes
1answer
52 views

How is boiling oil tolerated by some people?

There are people who can withstand exposure to extreme heat with no apparent side effects. One such person is Kann Trichan, a Thai street vendor who dips his bare hands in hot oil. An old TV show ...
1
vote
0answers
29 views

How does salicylic acid work on acne?

There are claims that salicylic acid has an effect on acne. I have done preliminary research and found multiple sources saying: "Salicylic acid [can] help prevent future breakouts." - https:...
1
vote
1answer
65 views

By what physiological mechanism do we not feel microbes (bacteria, etc.) living on our skin?

Background I know our bodies have a handful of ways to threshold our awareness of sensory stimuli: Neural density Sensory acuity I assume really tiny stimuli could fit between receptors e.g., ...
0
votes
1answer
51 views

How far can free radicals from UV radiation diffuse through the skin?

UV radiation damages DNA through two separate mechanisms. Direct damage occurs when a photon is absorbed by DNA. Indirect damage occurs when a photon is absorbed by a chromophore, and the excited ...
0
votes
1answer
36 views

Are facial 'cleansing' products 'effective' on human skin, and if so, what is their mechanism of action? [closed]

All major supermarkets and beauty stores stock some form of facial cleansing products. They come in the form of scrubs, gels, and lotions which vary in application (from in shower, to apply daily ...
4
votes
1answer
120 views

Why does hair turn white but not skin?

From my understanding melanocyte stem cells (McSCs) stop being produced and we have a finite reserve that gets depleted with time. They're at the origin of melanocytes that create hair and skin ...
0
votes
0answers
85 views

Do we as humans develop tolerance to deodorants or antiperspirants?

Do we as humans develop tolerance to deodorants or antiperspirants? In particular when they contain isobutane, isopropyl, palmitate, isododecane, dimethicone, coconut oil, magnesium oxide, allantoin, ...
8
votes
1answer
918 views

How does skin healing work?

I stacked my bike and split my head right open. About three weeks later the scab falls off and the skin is sealed over, like magic! How does it all work? How does the brain know that part of the ...
0
votes
0answers
27 views

Do pyrocalciferol and isopyrocalciferol form in vertebrate skin?

I heard that pyrocalciferol and isopyrocalciferol can only be formed above 100°C/212°F, yet some images in the web depict them as forming in vertebrate skin. So, I wonder if pyrocalciferol and ...
5
votes
2answers
2k views

Why do we like to touch fluffy things?

I read this article but it didn't explain much. Is the fact people like to cuddle pets with fur connected anyhow with our past when our ancestors had fur as well - and therefore could evolve an ...
8
votes
3answers
12k views

Why are bald heads so “shiny”?

Why do males with baldness have shiny skin on their head, whereas we don't experience such "shiny skin" in other parts of body without hair.
14
votes
2answers
2k views

Can UV radiation be safe for the skin?

It is well known that UV radiation can damage the DNA and generally harm our skin. We also know that UV radiation helps on the production of melanin and Vitamin D. From what I could find, the DNA ...
5
votes
1answer
4k views

Can viruses pass through sweat pores?

I have read somewhere that viruses and other microbes can not penetrate skin but what about sweat pores? Can viruses pass through these pores?
1
vote
0answers
95 views

How hot water burn works?

At age of 6 I accidentally dipped my hand into a boiling indian curry(Sambar) which was in a large pot. I got a Boiling Water Burn(Just like in the picture but with a little more radius) in my hand ...
3
votes
1answer
743 views

Why hand washing causes skin to dry?

This seems counter intuitive: dry hands mean low humidity, so why when humidity is increased, by washing hands, they become even more dry, eventually? In particular, why such hand dryness is usually ...
1
vote
1answer
10k views

Consequence of touching Formaldehyde

I accidently touched formaldehyde some days ago. Skin on my hand got dehydrated as if I had placed it in salt solution. I washed it with water and it returned to normal state after 5 minutes. But now ...
4
votes
0answers
54 views

Evolution of scratching

Is scratching (aka the scratching reflex) thought to be inherited from a single vertebrate ancestor or is it something that evolved several times e.g. in birds, mammals etc., i.e. is it a case of ...
0
votes
0answers
30 views

What part of the skin is damaged under sun exposure?

How exactly does extensive sun exposure lead to skin damage and increase cancer risk. In which part of the skin is the sun doing the most damage. Is it in the epidermis or beneath ? I would like to ...
1
vote
0answers
88 views

What are the (statistically) normal pH levels in the most-outer part of human sexual organs?

What are the (statistically) normal pH values of the outer skin/epidermis of human sex organs (groin/crotch) in the male and female? e.g male testes, female vulva, male glans, the enveloping epiderm, ...
2
votes
0answers
47 views

Oil absorbed into human skin — where does it go?

For example, I apply petrolatum to my dry hands twice a day as in winter I am usually in a 20-30% RH environment. Within an hour, the petrolatum seems entirely absorbed. According to [1], ...
2
votes
2answers
2k views

Do skin mites reproduce on human face during night?

I've seen this circulating on social networks: I was wondering to what extent is it true. Do skin mites really get on the skin surface to reproduce? Why is it so?
0
votes
1answer
143 views

How are fingerprints formed?

I know what influences the fingerprints to be unique always. But what actually process is taken to make these as we grow?
15
votes
2answers
54k views

How hot can a beverage get without burning the tongue?

What is the maximum temperature that a beverage can be without burning the tongue? I suspect there's a maximum temperature that the surface tissue of a tongue can withstand without being damaged (...
0
votes
1answer
515 views

Is there any difference between fascia and skin ?Are both the different names of the same thing?

Skin is the outermost layer of the body ,and it consists of two layers; epidermis and the second layer the dermis .There is another layer the (third layer) beneath the dermis called superficial fascia ...
4
votes
1answer
98 views

Skin Colour in “Northern” Regions of The earth

Question: Netflix has recently produced a two-part miniseries, The Evolution of US, that examines the evolution of "man". The topic of of human skin colour was covered and it was stated that 'lighter ...
8
votes
1answer
319 views

Do “scars” in humans replace all the skin layers or only some layers?

When someone has a cut or surgical incision that results in a "scar", is the scar tissue replacing all 3 layers of the skin (epidermis, dermis, hypodermis)? Or only the first one or two of them?
0
votes
1answer
39 views

why finger of hands and feet become wrinkled due to to water? [duplicate]

Mostly due to bathing or washing clothes our finger become wrinkled what was the reason behind it??
1
vote
1answer
47 views

Skin (histology)

Our instructor share this image with us. She didn't specify much. She only said it was a skin sample. Could you tell me what is the thing that was pointed at with the blue arrow? I believe that I ...
1
vote
0answers
178 views

What is the evolutionary advantage of getting hard nipples when being aroused? Why can they even be stimulated sexually?

I try to understand the evolutionary advantages of the body reactions of nipples and penises/vaginas. I'm confused, because I can explain the evolutionary advantage in a logical & consistent way ...
4
votes
1answer
2k views

What percentage of human capillaries are located in the skin?

As in the subject line, what percentage of capillaries in a human (expressed in terms of total length, I suppose) are located in the skin, as opposed to internal organs? Google scholar has not turned ...
1
vote
1answer
47 views

Which kind of drugs get absorbed through epidermis?

Some drugs such as nicotine can be administered through skin. I thought the layers of skin are designed to prevent in-flow of any chemical/germs. Not all drugs get absorbed in this fashion. So do ...
3
votes
0answers
53 views

How are animal patterns encoded in the dna?

After seeing the patterns on the feathers of a argusianus argus pheasant (shown below), I am curious where is the information that encodes a pattern for a particular bird, and what form is this ...
0
votes
1answer
78 views

Why do scabs itch?

I have noticed that scabs formed over wounds itch a lot. And if the scab comes off then the skin rarely completely heals and a scar is left. Assuming scabs are important for the healing of skin ,...
0
votes
1answer
1k views

What counts as a 'breach of the skin' for infections(like rabies) that spread via wounds?

I've been looking at several sources on how the virus spreads and they all mention that the skin has to be broken, but does it mean broken to the naked eye? A minor scratch where the skin appears ...
7
votes
1answer
16k views

My hand was stabbed with a pencil tip 10 years ago - why is the graphite still visible?

I, and multiple people that I know, have permanent marks (up to 30 years) from a graphite pencil puncturing the skin. The palm of my hand still shows a very clear mark where my hand was punctured by a ...
0
votes
0answers
39 views

Is swimming pool water actually a weak topical medication?

I was inspired by this question. Given that the chlorine levels in swimming pool water are so high that they can seriously harm amphibians, it seems logical that the water should also kill various ...
1
vote
0answers
64 views

Are there wounds which never completely heal?

I have a cut on a knuckle which occasionally opens (usually during winter), to disappear after some time (it is usually fine during the summer). This is going on for years now and yes, I will show ...
0
votes
1answer
390 views

What kind of factors determine how someone looks according to their race or ethnicity?

From what I read, race is considered the biology, the physical traits inherited by ancestry. Ethnicity and nationality have to do with social construct and cultural identity. This is almost the same ...
9
votes
1answer
654 views

How and why do skin tags develop?

WebMD writes: Skin tags are small, soft pieces of skin that stick out on a thin stem. They most often appear on the neck, armpits, upper trunk, and body folds. The cause of skin tags is not known. ...
3
votes
1answer
1k views

Why does UVA penetrate deeper than UVB, though it's weaker?

Even though UVA radiation ranges in longer wavelengths (315–400 nm) than UVB (280–315 nm) and thus is less energetic, UVA is able to penetrate deeper into the skin and even reach the dermis. Why is ...
1
vote
0answers
128 views

Can skin acclimatize to a the humidity level?

When the outdoor temperature is low, the absolute humidity is low because cold air holds less water. When the heat is turned up indoors the relative humidity decreases and during days with cold ...
3
votes
0answers
156 views

Mammalian scales

Many small mammals have scaly skin on their tails and sometimes limbs. The examples can be found among rodents (rats, degu, scaly-tailed squirrels), insectivores (shrews, desmans), oppossums, musky ...
4
votes
1answer
643 views

Function of Smooth Muscles in the skin

I understand that the overall function is voluntary movement, but is it the same in the skin? Is the main function in the skin movement or is there a greater function? Could anyone could provide this ...