What cells cover the surface of the skin? Skin Structure

In this paper we propose to talk about whichcells cover the surface of the skin. What is the skin, and what layers does it consist of. To begin with, it performs many different functions, among which:

• aesthetic;
• protection against mechanical damage;
• protection against thermal damage;
• protection against biological damage;
• touch;
• enrichment with oxygen.

Agree, all this is necessary for ourlife activity. The skin consists of several layers: epidermis, dermis and hypodermis. Today we will especially pay attention to the uppermost layer - the epidermis. Consider the layers from which the epidermis is formed, its thickness, and for how long it is fully capable of renewing.

Epidermis

So which cells cover the surface of the skin? This cells are the layer of the epidermis. We see it, it is a horny layer. It is an inanimate shell, it eventually peels off, that is completely dies. In the epidermis there are absolutely no blood vessels. But in the depth of this layer are living cells. They divide and gradually make their way to the upper layer, the cells themselves die and turn into scales.

Under this layer, water can not practically fall,but fat-soluble substances penetrate almost without problems. Why is this happening? Membranes of cells consist of fats, they are able to dissolve others.

Cells of the epidermis

Like any other organs, our skin is made up of cells. Now we will analyze which cells cover the surface of the skin, that is, from what particles the epidermis is composed.

The first thing worth mentioning is keratinocytes, which produce keratin. They are divided into three groups:

• spiny;
• basal;
• granular.

Keratinocytes are always in motion, theyadvance along the layers of the epidermis, trying to get out into the upper layer. During this, a very strong protein, keratin, is produced. When they lose the nucleus, they become like a bag, now they are called corneocytes. When the cells reach the top, they will simply fall off, and the next keratinocyte will come to this place. This process occurs quickly in a young organism, and with age all processes slow down.

Thickness

We figured out what cells coversurface of the skin, but did not say anything about the thickness of the layer we are considering. It is not uniform everywhere. There are places where the thickness reaches two millimeters, and in some areas of our body it is equal to seven hundredth of a millimeter. The thinnest parts of the epidermis are equal to the thickness of the polyethylene film.

For example, compare the skin on the heels, arm andeyelids. Agree, everywhere the thickness is different. Moreover, on the heels the cornification is more pronounced, and the skin of the eyelids is always smooth and tender. Genital organs also have a very thin layer of epidermis (about 0.1 millimeters).

Update

We discussed the question of which cells are coveredsurface of the skin. The surrounding world is a fascinating subject, it allows to learn a lot of new and interesting things for children, to discover new boundaries of knowledge. This topic is also included in the course of study.

From the renewal of the skin depends our appearance, inday, a person loses about 10 billion cells, this process slows down over time. On average, a person sheds 20 kilograms of skin per year. The healthier and younger our skin, the more intensive the exchange of cells, the old ones peel off, the new ones are replaced. When the body grows old, the process slows down, so wrinkles appear. Together with the dead cells, many harmful substances also leave. It is the epidermis that prevents harmful bacteria from entering the body. The update takes place over a period of 21 days to three months, it all depends on age.

Layers of the epidermis

The question of which cells cover the surfaceskin, the 4th grade of the course of the surrounding world must necessarily include. After all, from the very childhood, people should know that the skin is our shield. If you do not take care of her, then the entire body will suffer.

One should also know that the epidermis also includes several layers:

• basal;
• prickly;
• grainy;
• brilliant;
• horny.

With all this, the stratum corneum consists of approximately15 levels. The upper layers of cells can be considered dead, because they do not have the ability to share, and the inner layers have a core, so they are alive. The very boundary separating the dead and living cells is in the spiny layer.