Human skin

Main article: Human body

Main article: Electrical activity of the skin

Skin structure

An incredible photograph of a random incision of layers of the epidermis and dermis. A rare look at the anatomy of tiny blood vessels under a layer of skin.

The skin consists of several layers:

• Epidermis
• Term
• Subcutaneous fat

Aqueous lipid acid mantle

The skin surface is covered with an aqueous lipid acid mantle, or Marchionini mantle, consisting of a mixture of sebum and sweat, to which organic acids are added - lactic, citric and other, formed as a result of biochemical processes occurring in the epidermis.

Sweat

Main article: Sweat

Sebum

Sebaceous gland activity cannot be changed

Advertising many cosmetics promises to regulate the activity of sebaceous glands and/or actively fight oily skin.

Don't believe it, it's outright nonsense! The sebaceous glands are very deep in the skin, on the second underground floor in the dermis. Not a single cream will penetrate there; even prescription-only special acne creams cannot affect the overabundance of sebum production.

Black dots

When there is a lot of sebum, it stagnates in the sebaceous gland, mixes in keratin scales and thickens. As a result, the follicle estuary expands, the sebaceous plug stretches the pores.

Black dots become visible on the surface of the skin - the sebaceous cork creates conditions for the appearance of open comedones, and its apex is the oxidized secretion of the sebaceous gland.

It is impossible to change the genetically embedded pore size, but it is important to prevent their further expansion.

Epidermis

The epidermis assumes the full impact of adverse environmental effects. The most "injured" areas of the skin - the palms and feet - are covered with a vast stratum corneum - the scales into which keratinocytes turn during their natural development, in other areas the severity of the stratum corneum is less.

Dermis and subcutaneous fat

Under the epidermis is the dermis (lat. Dermis - skin). It contains:

• blood and lymphatic vessels;
• sebaceous and sweat glands;
• hair follicles;
• macrophages and antigen presenting cells that trigger an immune response upon contact with foreign microorganisms.

Deeper under the dermis lies a layer of subcutaneous fat. It contains adipose tissue that has many important functions.

Skin functions

By convention, all numerous skin functions can be combined into three main ones: barrier, regulatory and sensory.

Barrier (protective) function

Skin is an indispensable organ that covers the human body, protecting it from external influences:

• toxic substances,
• microorganisms,
• sunlight,
• moisture,
• cold,
• high temperatures,
• mechanical damages.

Mechanical protection is provided by cells of the constantly renewing epidermis. Its stratum corneum, the most superficial, consists of strong dead scales.

Keratin, collagen and elastin ensure skin elasticity and strength.

In the lower (basal) layer of the epidermis are melanocytes - cells containing the pigment melanin, which protects the skin from ultraviolet radiation. Melanocytes can develop the most dangerous of skin tumors - melanoma.

Langerhans cells (the spiny layer of the epidermis) are responsible for immunity in the skin.

Sebaceous glands secrete a secret called sebum, which ensures skin elasticity and repels moisture.

Regulatory function

First of all, the skin is a powerful thermoregulation organ. When the ambient temperature decreases, the muscle fibers of the papillary layer of the dermis contract. This leads to a decrease in blood flow to all layers of the skin and a decrease in heat output. Hair cover also protects the body from hypothermia.

The evaporation of sweat leads to cooling of the body surface at high temperatures. Also, with later, a large amount of nitrogen exchange products and an excess of salts are released.

With an increase in temperature, reflex dilation of the skin vessels occurs, which increases the return of heat.

Subcutaneous fat fiber is a depot for storing supplies of fluids, nutrients and fat-soluble vitamins, including vitamin D. Also, part of the female sex hormones is formed here.

Touch function

In the epidermis are Merkel and Paccini cells, responsible for tactile sensations, forming skin sensitivity.

There are many nerve endings in the dermis, there are also receptors:

• cold,
• thermal,
• pain.

Reflex arcs begin in the skin, causing us to unknowingly pull our hand away from hot objects.

Scalp

The scalp is cared for by two types of fats: pore-borne sebum and barrier fats produced by the top layer of the skin (epidermis) during a long four-week process.

Fats displace unwanted pathogens.

Skin diseases

• Skin cancer
• Argyrosis - increased deposition of silver ions
• Rosacea - facial dilation and skin redness

Diagnosis of skin diseases

2023

For the first time, a tool for analyzing human skin health using a smartphone camera was built into the processor

On October 24, 2023, the German company trinamiX GmbH announced the first in the industry solution for smartphones and mobile devices, allowing you to obtain health data using skin scans. It is assumed that the technology will open up new opportunities in terms of diagnosing disorders and improving the quality of life. Read more here.

Flexible sensors designed to detect heavy metals in sweat

In late January 2023, researchers from the University of São Paulo in Brazil, along with colleagues from Germany and Sweden, unveiled a flexible sensor that can detect heavy metals in sweat. Read more here.

2022: Russia has created a technology for automatic analysis of skin conditions to detect neoplasms

In December 2022, the Samara National Research University named after S.P. Korolev announced the creation of a technology for non-invasive automatic analysis of the skin condition and a special portable installation for detecting neoplasms or acne. Read more here.

2021: Derm Assist service launch to identify skin diseases by photo

At the end of May 2021, Google launched the Derm Assist service, designed to determine skin diseases by photo based on artificial intelligence. Users only need to upload three well-lit images of problematic skin, hair or nails from different angles. The tool then asks a series of questions about the user's skin type, whether a problem is long ago, and other symptoms that help the tool narrow down capabilities. Read more here.

2017: iPhone taught to detect skin diseases with camera

In the fall of 2017, the VisualDx service received a new function: using the iPhone camera and machine learning algorithms, the application automatically detects the skin condition and issues a preliminary diagnosis. The program either detects diseases with high accuracy, or significantly narrows their circle, helping doctors and even patients themselves determine what they are sick with. Read more here.

Treatment of skin diseases

2024: High levels of cancer-causing chemical benzene found in dozens of acne remedies

In March 2024, it became known that high levels of the cancer-causing chemical benzene were found in dozens of acne remedies. Dangerous creams include Proactiv, Clearasil and Target products.

2023

Gloves began to be printed on a 3D printer for quick replacement of skin on the hands

In mid-February 2023, scientists from the Irving Medical Center at Columbia University presented a method for creating three-dimensional bioengineered skin grafts. Researchers have already created a skin glove that can be useful for replacing skin on the hands by simply putting it on your arm like a glove. Read more here.

A device has been released to treat skin diseases using radio frequencies

On February 6, 2023, Candela announced the release of the new Profound Matrix system for the treatment of skin diseases using radio frequencies. The complex is designed to correct, maintain and restore skin at various stages of its aging. Read more here.

Electrical activity of the skin

Main article: Electrical activity of the skin

Artificial skin

• Artificial skin in medicine