10 Characteristics of the Skin

We explain what skin is, its structure and thickness. We also explain its characteristics and its ability to self-repair.

What is Skin?

The skin is the largest organ in the human bodyIn an adult, this organ can reach almost 2 square meters. It is composed of two layers: the epidermis and the dermis. Below these two layers is a layer (subcutaneous layer) called hypodermis.

In the innermost part of the skin, cells are formed which gradually move towards the outer layers, losing their core and becoming loaded with keratin. In this way they can form a protective layer for the body. However, this layer is constantly being renewed.

The significant loss of a portion of skin can lead to death.

See also: Nuclear membrane.

Skin characteristics:

  1. Layers

As we have said above, the skin is made up of 2 layers.

  • Epidermis. It is the outermost and thinnest layer of the skin. This layer is completely replaced every 2 or 3 weeks. It is subdivided into different strata or layers:
    • Horny layer. It consists of about 15 or 20 layers of horny cells. The outermost layer of this is fragile and contains old cells that are shed from the skin, giving way to the arrival of new cells.
    • Lucid layer. It is formed by a single row of flattened cells without a nucleus.
    • Granular layer. In these layers are found the cells with a high protein content in the cytoplasm.
    • Basal layer. The cells that compose it have a cylindrical and cubic shape and have great elasticity.
    • Spiny layer. They are polygonal-shaped cells with a central nucleus and are surrounded by basal cells.
  • Dermis. It is the layer that continues to the epidermis. It is formed by a network of protein fibers, mostly of collagenThe dermis is strong and thick but, at the same time, it is flexible, thanks to the elastina protein that contains. This, in turn, is divided into:
    • Papillary dermis. It has constant contact and exchange with the epidermis.
    • Reticular dermis. It is the deepest and thickest layer of the dermis.

  1. Hypodermis

As mentioned above The hypodermis is located beneath the dermis.between the skin and the muscles. Technically, it is not a layer of skin but rather a subcutaneous layer.

Genetically speaking, This hypodermis is thicker in women than in men.. It is made up of adipocytes that store fat. Basically, the hypodermis is responsible for storing fat, serves as an energy reservoir and is a thermal insulator for the body.

  1. Hydrolipidic film

This movie It is found in the skin layer, made up of water and fat.This film provides elasticity and protects the skin from bacteria and fungi. Its pH is slightly acidic: between 5.4 and 5.9. It is this acidity (composed of bacterial flora) that makes it a protective layer for microbes.

  1. Thickness

The thickness of the skin will vary depending on the area of ​​the body it covers. Thus, In the face or hands area it is 0.02 mm and in the feet it can reach between 1 and 5 mm. In the areas around the eyes and on the eyelids it can reach a thickness of 0.004 mm. On average, the skin is 0.01 mm thick.

  1. Flexibility and waterproofing

The skin It is flexible thanks to the elastin that possesses the dermisHowever, over the years this elasticity can be lost, giving rise to the well-known skin wrinkles.

Besides The skin is impermeable, that is, it prevents the passage of fluids. and substances thus protecting the internal organs of the body.

  1. Thermostat

One of the distinctive features of the skin is that serves as a regulator of body temperature. Thus, and through sweating of the skin, it can allow the exit of water through the sweat glands.

  1. The function of melanin

Melanin is the substance responsible for the color of our skin and hairAs the years go by, melanin production can be altered. This is why at a certain age grey hair or spots on the hands and face begin to appear.

  1. The importance of hair on the skin

Hair on the skin helps with body temperature regulation functions, maintaining humidity and avoiding damage from external agents such as UV rays, environmental pollution or germs that may be present in the air. On the other hand, the sensory function is expressed through the sense of touch.

  1. Calcium fixation

Vitamin D, which is essential for the health of the body, can only be fixed through contact between the skin and the sun’s rays. In this way, The skin is involved in the synthesis of vitamin D.

  1. Self-repair capability

When the skin has been damaged by some factor, it has the ability to regenerate itself. This It occurs as cells travel from the hypodermisthey release their nucleus and reach the outer layer of the dermis where they take the place of old cells (which are shed from the skin) and give rise to new cells.

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