Is Skin Really The Biggest Organ?

Outer covering of the body

This article is about skin in humans. For other mammals, see Pare.

Peel
Epidermis, dermis, and subcutis, showing a hair follicle, gland, and sebaceous gland
Details
System	Integumentary system
Identifiers
Latin	cutis
MeSH	D012867
TA98	A16.0.00.002
TA2	7041
TH	H3.12.00.ane.00001
FMA	7163
Anatomical terminology [edit on Wikidata]

The human being peel is the outer roofing of the body and is the largest organ of the integumentary system. The peel has upwards to 7 layers of ectodermal tissue guarding muscles, bones, ligaments and internal organs. Human peel is like to nigh of the other mammals' skin, and it is very similar to grunter skin. Though almost all human skin is covered with hair follicles, it tin can announced hairless. There are 2 general types of peel, hairy and glabrous skin (hairless). The adjective cutaneous literally means "of the skin" (from Latin cutis, peel).

Because it interfaces with the environs, pare plays an important immunity function in protecting the body against pathogens and excessive water loss. Its other functions are insulation, temperature regulation, awareness, synthesis of vitamin D, and the protection of vitamin B folates. Severely damaged pare will endeavour to heal by forming scar tissue. This is often discoloured and depigmented.

In humans, peel pigmentation (affected by melanin) varies among populations, and peel type tin can range from dry to non-dry out and from oily to not-oily. Such peel variety provides a rich and diverse habitat for bacteria that number roughly 1000 species from 19 phyla, present on the human skin.

Construction [edit]

Human pare shares anatomical, physiological, biochemical and immunological properties with other mammalian lines, especially pig skin.^{[1] [2]} Pig skin shares like epidermal and dermal thickness ratios to homo skin;^{[1] [2]} pig and human being pare share similar pilus follicle and blood vessel patterns;^{[one] [2]} biochemically the dermal collagen and elastic content is similar in pig and human skin;^{[i] [ii]} and pig skin and human skin have like physical responses to diverse growth factors.^{[i] [2]}

Peel has mesodermal cells, pigmentation, such as melanin provided by melanocytes, which absorb some of the potentially unsafe ultraviolet radiation (UV) in sunlight. It also contains DNA repair enzymes that help opposite UV impairment, such that people defective the genes for these enzymes endure loftier rates of skin cancer. One form predominantly produced by UV low-cal, cancerous melanoma, is particularly invasive, causing information technology to spread chop-chop, and can oft be mortiferous. Man pare pigmentation varies among populations in a striking manner. This has led to the classification of people(s) on the footing of skin colour.^[3]

In terms of surface surface area, the skin is the second largest organ in the human body (the within of the pocket-size intestine is 15 to twenty times larger). For the average adult human, the pare has a surface surface area of from 1.5–two.0 square metres (sixteen–22 sq ft). The thickness of the skin varies considerably over all parts of the body, and between men and women and the young and the old. An example is the skin on the forearm which is on average 1.three mm in the male and i.26 mm in the female.^[4] Ane average square inch (6.v cm²) of skin holds 650 sweat glands, xx blood vessels, 60,000 melanocytes, and more than 1,000 nervus endings.^{[v] [ amend source needed ]} The boilerplate human pare prison cell is near 30 micrometres (μm) in diameter, only there are variants. A skin cell usually ranges from 25–40 μm^two, depending on a variety of factors.

Skin is equanimous of three chief layers: the epidermis, the dermis and the hypodermis.^[four]

Layers, Receptors, and Appendages of Human Skin

Epidermis [edit]

Epidermis, "epi" coming from the Greek significant "over" or "upon", is the outermost layer of the skin. It forms the waterproof, protective wrap over the body'due south surface which also serves as a bulwark to infection and is made up of stratified squamous epithelium with an underlying basal lamina.

The epidermis contains no blood vessels, and cells in the deepest layers are nourished nearly exclusively by diffused oxygen from the surrounding air^[6] and to a far bottom degree by blood capillaries extending to the outer layers of the dermis. The main type of cells that make upwardly the epidermis are Merkel cells, keratinocytes, with melanocytes and Langerhans cells also present. The epidermis tin can be further subdivided into the post-obit strata (commencement with the outermost layer): corneum, lucidum (only in palms of hands and bottoms of feet), granulosum, spinosum, and basale. Cells are formed through mitosis at the basale layer. The girl cells (come across prison cell division) move up the strata changing shape and limerick as they die due to isolation from their blood source. The cytoplasm is released and the protein keratin is inserted. They eventually reach the corneum and slough off (desquamation). This process is called "keratinization". This keratinized layer of pare is responsible for keeping h2o in the body and keeping other harmful chemicals and pathogens out, making skin a natural bulwark to infection.^[7]

second project of a 3D October-tomogram of the pare at the fingertip, depicting the stratum corneum (~500 µm thick) with the stratum disjunctum on top and the stratum lucidum in the center. At the lesser are the superficial parts of the dermis. The sweat ducts are conspicuously visible. (See also: Rotating 3D Version)

The epidermis contains no blood vessels and is nourished by diffusion from the dermis. The master type of cells that brand up the epidermis are keratinocytes, melanocytes, Langerhans cells, and Merkel cells. The epidermis helps the skin regulate body temperature.

Layers [edit]

The skin has upwardly to seven layers of ectodermal tissue and guards the underlying muscles, bones, ligaments and internal organs.^[8] The epidermis is divided into several layers, where cells are formed through mitosis at the innermost layers. They move up the strata changing shape and limerick as they differentiate and go filled with keratin. After reaching the top layer stratum corneum they are somewhen 'sloughed off', or desquamated. This process is called keratinization and takes place within weeks.

It was previously believed that the stratum corneum was "a simple, biologically inactive, outer epidermal layer comprising a fibrillar lattice of dead keratin".^[nine] It is at present understood that this is not true, and that the stratum corneum should exist considered to exist a live tissue.^[10] While information technology is truthful that the stratum corneum is mainly composed of terminally differentiated keratinocytes chosen corneocytes that are anucleated, these cells remain alive and metabolically functional until desquamated.^{[ citation needed ]}

Sublayers [edit]

The epidermis is divided into the post-obit 5 sublayers or strata:

• Stratum corneum
• Stratum lucidum
• Stratum granulosum
• Stratum spinosum
• Stratum basale (also chosen "stratum germinativum")

Blood capillaries are found beneath the epidermis and are linked to an arteriole and a venule. Arterial shunt vessels may bypass the network in ears, the nose and fingertips.

Genes and proteins expressed in the epidermis [edit]

Virtually 70% of all man poly peptide-coding genes are expressed in the skin.^{[11] [12]} Nigh 500 genes have an elevated design of expression in the skin. In that location are less than 100 genes that are specific for the skin, and these are expressed in the epidermis.^[13] An analysis of the corresponding proteins bear witness that these are mainly expressed in keratinocytes and accept functions related to squamous differentiation and cornification.

Dermis [edit]

The dermis is the layer of skin beneath the epidermis that consists of connective tissue and cushions the body from stress and strain. The dermis is tightly connected to the epidermis by a basement membrane. It also harbours many nerve endings that provide the sense of touch and oestrus. Information technology contains the pilus follicles, sweat glands, sebaceous glands, apocrine glands, lymphatic vessels and claret vessels. The claret vessels in the dermis provide nourishment and waste matter removal from its ain cells as well every bit from the stratum basale of the epidermis.

The dermis is structurally divided into 2 areas: a superficial area adjacent to the epidermis, called the papillary region, and a deep thicker area known as the reticular region.

Papillary region [edit]

The papillary region is equanimous of loose areolar connective tissue. It is named for its finger-similar projections called papillae, which extend toward the epidermis. The papillae provide the dermis with a "bumpy" surface that interdigitates with the epidermis, strengthening the connection betwixt the two layers of skin.

In the palms, fingers, soles, and toes, the influence of the papillae projecting into the epidermis forms contours in the skin'southward surface. These epidermal ridges occur in patterns (run across: fingerprint) that are genetically and epigenetically adamant and are therefore unique to the individual, making it possible to employ fingerprints or footprints as a means of identification.

Reticular region [edit]

The reticular region lies deep in the papillary region and is commonly much thicker. It is composed of dumbo irregular connective tissue, and receives its name from the dumbo concentration of collagenous, elastic, and reticular fibres that weave throughout it. These protein fibres give the dermis its properties of strength, extensibility, and elasticity.

Also located within the reticular region are the roots of the hairs, sebaceous glands, sweat glands, receptors, nails, and claret vessels.

Tattoo ink is held in the dermis. Stretch marks, often from pregnancy and obesity, are as well located in the dermis.

Subcutaneous tissue [edit]

The subcutaneous tissue (also hypodermis and subcutis) is not part of the skin, merely lies below the dermis of the cutis. Its purpose is to adhere the skin to underlying bone and muscle as well as supplying it with claret vessels and nerves. Information technology consists of loose connective tissue, adipose tissue and elastin. The main cell types are fibroblasts, macrophages and adipocytes (subcutaneous tissue contains fifty% of body fat). Fat serves as padding and insulation for the body.

Cross-section [edit]

Skin layers, of both hairy and hairless skin

Development [edit]

Pare colour [edit]

Human being pare shows high skin colour diversity from the darkest dark-brown to the lightest pinkish-white hues. Human skin shows higher variation in colour than any other single mammalian species and is the issue of natural selection. Pare pigmentation in humans evolved to primarily regulate the amount of ultraviolet radiation (UVR) penetrating the skin, decision-making its biochemical furnishings.^[14]

The actual skin color of unlike humans is affected past many substances, although the single most important substance determining human skin colour is the pigment melanin. Melanin is produced inside the pare in cells called melanocytes and it is the primary determinant of the skin color of darker-skinned humans. The skin colour of people with lite skin is determined mainly by the bluish-white connective tissue under the dermis and by the haemoglobin circulating in the veins of the dermis. The red color underlying the pare becomes more than visible, especially in the confront, when, as upshot of physical practise or the stimulation of the nervous system (anger, fear), arterioles amplify.^[15]

There are at least five different pigments that decide the colour of the pare.^{[16] [17]} These pigments are present at unlike levels and places.

• Melanin: Information technology is chocolate-brown in colour and present in the basal layer of the epidermis.
• Melanoid: Information technology resembles melanin but is present diffusely throughout the epidermis.
• Carotene: This pigment is yellow to orange in color. Information technology is present in the stratum corneum and fat cells of dermis and superficial fascia.
• Hemoglobin (also spelled haemoglobin): It is found in blood and is non a paint of the skin but develops a majestic colour.
• Oxyhemoglobin: Information technology is also found in blood and is non a pigment of the skin. It develops a red colour.

There is a correlation betwixt the geographic distribution of UV radiation (UVR) and the distribution of indigenous pare pigmentation around the world. Areas that highlight higher amounts of UVR reflect darker-skinned populations, mostly located nearer towards the equator. Areas that are far from the tropics and closer to the poles accept lower concentration of UVR, which is reflected in lighter-skinned populations.^[18]

In the same population it has been observed that developed human females are considerably lighter in skin pigmentation than males. Females need more calcium during pregnancy and lactation, and vitamin D which is synthesized from sunlight helps in absorbing calcium. For this reason it is idea that females may accept evolved to have lighter skin in order to assist their bodies absorb more than calcium.^[nineteen]

The Fitzpatrick calibration^{[xx] [21]} is a numerical classification schema for man skin colour adult in 1975 as a fashion to classify the typical response of different types of pare to ultraviolet (UV) low-cal:

I	Always burns, never tans	Pale, Off-white, Freckles
2	Normally burns, sometimes tans	Fair
Iii	May burn down, unremarkably tans	Lite Brown
IV	Rarely burns, always tans	Olive brown
V	Moderate constitutional pigmentation	Brown
VI	Marked constitutional pigmentation	Black

Ageing [edit]

As skin ages, it becomes thinner and more easily damaged. Intensifying this consequence is the decreasing ability of skin to heal itself every bit a person ages.

Among other things, skin ageing is noted by a subtract in volume and elasticity. There are many internal and external causes to skin ageing. For case, ageing skin receives less blood flow and lower glandular activity.

A validated comprehensive grading scale has categorized the clinical findings of pare ageing as laxity (sagging), rhytids (wrinkles), and the various facets of photoageing, including erythema (redness), and telangiectasia, dyspigmentation (brown discolouration), solar elastosis (yellowing), keratoses (abnormal growths) and poor texture.^[22]

Cortisol causes degradation of collagen,^[23] accelerating skin ageing.^[24]

Anti-ageing supplements are used to treat peel ageing.^{[ citation needed ]}

Photoageing [edit]

Photoageing has two chief concerns: an increased run a risk for skin cancer and the appearance of damaged peel. In younger peel, sunday damage will heal faster since the cells in the epidermis have a faster turnover charge per unit, while in the older population the pare becomes thinner and the epidermis turnover rate for cell repair is lower, which may result in the dermis layer being damaged.^[25]

Types [edit]

This section needs expansion. You lot can aid by adding to it. (March 2022)

Though nigh man skin is covered with hair follicles, some parts can exist hairless. There are two general types of skin, hairy and glabrous pare (hairless).^[26] The describing word cutaneous ways "of the peel" (from Latin cutis, skin).^[27]

Functions [edit]

Pare performs the following functions:

1. Protection: an anatomical barrier from pathogens and damage between the internal and external environment in bodily defence; Langerhans cells in the peel are part of the adaptive immune system.^{[seven] [28]} Perspiration contains lysozyme that break the bonds within the cell walls of bacteria.^[29]
2. Sensation: contains a variety of nerve endings that react to heat and cold, touch, pressure, vibration, and tissue injury; see somatosensory organization and haptics.
3. Oestrus regulation: the peel contains a claret supply far greater than its requirements which allows precise control of energy loss by radiations, convection and conduction. Dilated blood vessels increase perfusion and oestrus loss, while constricted vessels greatly reduce cutaneous claret flow and conserve heat.
4. Command of evaporation: the skin provides a relatively dry out and semi-impermeable bulwark to fluid loss.^[28] Loss of this function contributes to the massive fluid loss in burns.
5. Aesthetics and advice: others see our skin and tin can assess our mood, physical state and attractiveness.
6. Storage and synthesis: acts equally a storage centre for lipids and water, as well every bit a means of synthesis of vitamin D by action of UV on certain parts of the pare.
7. Excretion: sweat contains urea, however its concentration is 1/130th that of urine, hence excretion by sweating is at almost a secondary office to temperature regulation.
8. Absorption: the cells comprising the outermost 0.25–0.twoscore mm of the skin are "most exclusively supplied by external oxygen", although the "contribution to total respiration is negligible".^[vi] In addition, medicine can be administered through the skin, by ointments or by means of adhesive patch, such every bit the nicotine patch or iontophoresis. The pare is an important site of ship in many other organisms.
9. Water resistance: The skin acts every bit a h2o-resistant barrier so essential nutrients are not done out of the trunk.^[28]

Pare flora [edit]

The man skin is a rich surroundings for microbes.^{[thirty] [31]} Around g species of leaner from xix bacterial phyla accept been found.^{[31] [30]} Most come up from only four phyla: Actinomycetota (51.8%), Bacillota (24.four%), Pseudomonadota (16.5%), and Bacteroidota (6.3%). Propionibacteria and Staphylococci species were the principal species in sebaceous areas. There are three main ecological areas: moist, dry out and sebaceous. In moist places on the body Corynebacteria together with Staphylococci dominate. In dry areas, at that place is a mixture of species but dominated by Betaproteobacteria and Flavobacteriales. Ecologically, sebaceous areas had greater species richness than moist and dry ones. The areas with least similarity between people in species were the spaces between fingers, the spaces between toes, axillae, and umbilical cord stump. Most similarly were beside the nostril, nares (inside the nostril), and on the back.

Reflecting upon the diversity of the human skin researchers on the human skin microbiome have observed: "hairy, moist underarms lie a curt distance from smooth dry forearms, but these two niches are likely equally ecologically dissimilar as rainforests are to deserts."^[30]

The NIH conducted the Human Microbiome Projection to characterize the human microbiota which includes that on the skin and the role of this microbiome in health and illness.^[32]

Microorganisms like Staphylococcus epidermidis colonize the skin surface. The density of skin flora depends on region of the skin. The disinfected skin surface gets recolonized from bacteria residing in the deeper areas of the hair follicle, gut and urogenital openings.

Clinical significance [edit]

Diseases of the peel include pare infections and skin neoplasms (including peel cancer). Dermatology is the branch of medicine that deals with conditions of the peel.^[26]

The pare is as well valuable for diagnosis of other conditions, since many medical signs show through the pare. Skin colour affects the visibility of these signs, a source of misdiagnosis in unaware medical personnel.^{[33] [34]}

Society and culture [edit]

Hygiene and skin intendance [edit]

The pare supports its own ecosystems of microorganisms, including yeasts and bacteria, which cannot exist removed by any amount of cleaning. Estimates place the number of individual bacteria on the surface of six.5 square centimetres (ane sq in) of human peel at 50 million, though this figure varies greatly over the boilerplate 1.9 square metres (20 sq ft) of man skin. Oily surfaces, such equally the face, may contain over 78 million bacteria per square centimetre (500 million per square inch). Despite these vast quantities, all of the bacteria institute on the skin's surface would fit into a book the size of a pea.^[35] In full general, the microorganisms keep one another in check and are function of a healthy skin. When the balance is disturbed, there may be an overgrowth and infection, such as when antibiotics impale microbes, resulting in an overgrowth of yeast. The skin is continuous with the inner epithelial lining of the body at the orifices, each of which supports its own complement of microbes.

Cosmetics should be used advisedly on the skin because these may cause allergic reactions. Each flavour requires suitable clothing in order to facilitate the evaporation of the sweat. Sunlight, h2o and air play an of import part in keeping the skin healthy.

Oily skin [edit]

Oily peel is caused by over-active sebaceous glands, that produce a substance called sebum, a naturally healthy skin lubricant.^{[8] [36]} A high glycemic-index diet and dairy products (except for cheese) consumption increase IGF-1 generation, which in plough increases sebum product.^[36] Overwashing the skin does non cause sebum overproduction simply may crusade dryness.^[36]

When the skin produces excessive sebum, information technology becomes heavy and thick in texture, known as oily skin.^[36] Oily skin is typified by shininess, blemishes and pimples.^[viii] The oily-skin type is non necessarily bad, since such pare is less prone to wrinkling, or other signs of ageing,^[8] because the oil helps to go along needed wet locked into the epidermis (outermost layer of skin). The negative attribute of the oily-skin type is that oily complexions are specially susceptible to clogged pores, blackheads, and buildup of expressionless skin cells on the surface of the skin.^[eight] Oily skin can be sallow and rough in texture and tends to have large, clearly visible pores everywhere, except around the eyes and neck.^[eight]

Permeability [edit]

Homo skin has a depression permeability; that is, most foreign substances are unable to penetrate and diffuse through the pare. Peel'south outermost layer, the stratum corneum, is an effective barrier to most inorganic nanosized particles.^{[37] [38]} This protects the body from external particles such as toxins by not allowing them to come up into contact with internal tissues. Notwithstanding, in some cases it is desirable to permit particles entry to the torso through the skin. Potential medical applications of such particle transfer has prompted developments in nanomedicine and biology to increase skin permeability. I application of transcutaneous particle delivery could be to locate and care for cancer. Nanomedical researchers seek to target the epidermis and other layers of agile cell sectionalisation where nanoparticles tin can interact directly with cells that have lost their growth-command mechanisms (cancer cells). Such straight interaction could be used to more accurately diagnose backdrop of specific tumours or to treat them by delivering drugs with cellular specificity.

Nanoparticles [edit]

Nanoparticles 40 nm in diameter and smaller have been successful in penetrating the pare.^{[39] [40] [41]} Research confirms that nanoparticles larger than twoscore nm do not penetrate the skin by the stratum corneum.^[39] Most particles that practice penetrate will diffuse through skin cells, but some will travel downwardly hair follicles and reach the dermis layer.

The permeability of skin relative to different shapes of nanoparticles has likewise been studied. Research has shown that spherical particles have a better ability to penetrate the pare compared to oblong (ellipsoidal) particles considering spheres are symmetric in all three spatial dimensions.^[41] One study compared the two shapes and recorded data that showed spherical particles located deep in the epidermis and dermis whereas oblong particles were mainly found in the stratum corneum and epidermal layers.^[42] Nanorods are used in experiments because of their unique fluorescent backdrop but have shown mediocre penetration.

Nanoparticles of different materials take shown peel's permeability limitations. In many experiments, gold nanoparticles 40 nm in diameter or smaller are used and have shown to penetrate to the epidermis. Titanium oxide (TiO₂), zinc oxide (ZnO), and silverish nanoparticles are ineffective in penetrating the skin past the stratum corneum.^{[38] [43]} Cadmium selenide (CdSe) quantum dots take proven to penetrate very finer when they accept certain properties. Because CdSe is toxic to living organisms, the particle must exist covered in a surface group. An experiment comparing the permeability of quantum dots coated in polyethylene glycol (PEG), PEG-amine, and carboxylic acid concluded the PEG and PEG-amine surface groups immune for the greatest penetration of particles. The carboxylic acid coated particles did not penetrate past the stratum corneum.^[42]

Increasing permeability [edit]

Scientists previously believed that the skin was an effective barrier to inorganic particles. Damage from mechanical stressors was believed to exist the just mode to increase its permeability.^[44]

Recently, simpler and more effective methods for increasing skin permeability have been adult. Ultraviolet radiation (UVR) slightly damages the surface of skin and causes a fourth dimension-dependent defect allowing easier penetration of nanoparticles.^[45] The UVR's high energy causes a restructuring of cells, weakening the boundary between the stratum corneum and the epidermal layer.^{[45] [44]} The damage of the skin is typically measured past the transepidermal water loss (TEWL), though it may have three–five days for the TEWL to reach its elevation value. When the TEWL reaches its highest value, the maximum density of nanoparticles is able to permeate the skin. While the issue of increased permeability after UVR exposure can lead to an increase in the number of particles that permeate the skin, the specific permeability of skin after UVR exposure relative to particles of different sizes and materials has non been determined.^[45]

There are other methods to increase nanoparticle penetration past skin damage: tape stripping is the process in which tape is applied to skin so lifted to remove the summit layer of peel; skin chafe is done by shaving the top 5–10 μm off the surface of the peel; chemical enhancement applies chemicals such as polyvinylpyrrolidone (PVP), dimethyl sulfoxide (DMSO), and oleic acid to the surface of the peel to increase permeability;^{[46] [47]} electroporation increases pare permeability by the awarding of curt pulses of electric fields. The pulses are high voltage and on the order of milliseconds when applied. Charged molecules penetrate the peel more frequently than neutral molecules after the skin has been exposed to electric field pulses. Results accept shown molecules on the order of 100 μm to hands permeate electroporated skin.^[47]

Applications [edit]

A large area of involvement in nanomedicine is the transdermal patch considering of the possibility of a painless awarding of therapeutic agents with very few side effects. Transdermal patches accept been express to administrate a modest number of drugs, such as nicotine, because of the limitations in permeability of the skin. Development of techniques that increase skin permeability has led to more drugs that tin exist applied via transdermal patches and more options for patients.^[47]

Increasing the permeability of pare allows nanoparticles to penetrate and target cancer cells. Nanoparticles forth with multi-modal imaging techniques have been used as a manner to diagnose cancer not-invasively. Skin with high permeability allowed quantum dots with an antibody fastened to the surface for active targeting to successfully penetrate and identify cancerous tumours in mice. Tumour targeting is beneficial because the particles tin be excited using fluorescence microscopy and emit low-cal free energy and heat that will destroy cancer cells.^[48]

Sunblock and sunscreen [edit]

Sunblock and sunscreen are different important skin-care products though both offer full protection from the sun.^{[49] [50]}

Sunblock—Sunblock is opaque and stronger than sunscreen, since it is able to block most of the UVA/UVB rays and radiation from the sun, and does not need to exist reapplied several times in a twenty-four hour period. Titanium dioxide and zinc oxide are 2 of the important ingredients in sunblock.^[51]

Sunscreen—Sunscreen is more than transparent in one case applied to the skin and also has the ability to protect against UVA/UVB rays, although the sunscreen'due south ingredients have the ability to break downwardly at a faster rate one time exposed to sunlight, and some of the radiation is able to penetrate to the skin. In guild for sunscreen to be more effective it is necessary to consistently reapply and use one with a higher sunday protection factor.

Diet [edit]

Vitamin A, as well known as retinoids, benefits the skin by normalizing keratinization, downregulating sebum production which contributes to acne, and reversing and treating photodamage, striae, and cellulite.

Vitamin D and analogues are used to downregulate the cutaneous immune system and epithelial proliferation while promoting differentiation.

Vitamin C is an antioxidant that regulates collagen synthesis, forms barrier lipids, regenerates vitamin Due east, and provides photoprotection.

Vitamin E is a membrane antioxidant that protects against oxidative damage and also provides protection against harmful UV rays. ^[52]

Several scientific studies confirmed that changes in baseline nutritional status affects peel condition. ^[53]

The Mayo Dispensary lists foods they state help the pare: fruits and vegetables, whole-grains, dark leafy greens, nuts, and seeds.^[54]

Run across also [edit]

• Acrid mantle
• Anthropodermic bibliopegy
• Artificial skin
• Callus, thick expanse of skin
• List of cutaneous atmospheric condition
• Cutaneous structure evolution
• Fingerprint, skin on fingertips
• Hyperpigmentation, about backlog skin color
• Intertriginous
• Meissner's corpuscle
• Pacinian corpuscle
• Polyphenol antioxidant
• Skin cancer
• Skin lesion
• Pare repair

References [edit]

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2. ^ ^{a b c d due east} Liu J, Kim D, Brown L, Madsen T, Bouchard GF. "Comparison of Human, Porcine and Rodent Wound Healing With New Miniature Swine Study Data" (PDF). sinclairresearch.com. Sinclair Research Centre, Auxvasse, MO, USA; Veterinary Medical Diagnostic Laboratory, Columbia, MO, USA. Retrieved 27 Jan 2018. Sus scrofa peel is anatomically, physiologically, biochemically and immunologically similar to homo skin
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16. ^ Handbook of General Beefcake past B. D. Chaurasia. ISBN 978-81-239-1654-5
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External links [edit]

Expect up human skin in Wiktionary, the free dictionary.

• Media related to Man skin at Wikimedia Commons
• MedlinePlus Peel Atmospheric condition National Library of Medicine retrieved 12 November 2013.

Source: https://en.wikipedia.org/wiki/Human_skin

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