Skin under the microscope: features of the structure
The skin under the microscope has a rather complex structure. In this article, we consider the structural features of the integument of the body at the cellular level.
Why is the skin an organ?
Our skin is not just a layer of epithelium. It is formed by several types of tissues. You can verify this by examining the skin under a microscope. In the photo below, cells of different shapes and sizes differ distinctly.
Therefore, the skin is also the organ - the largest inthe human body. It can weigh up to 3 kg with an average thickness of 4 mm. The total skin area is 1.5-2 m squared. In different parts of the body its thickness varies. The thickest and coarse it is in places of greatest friction. For example, on the soles of the feet.
Human skin under the microscope
The skin consists of three layers. The outer one is called the epidermis. It includes the epithelial tissue. The middle layer is the most massive, formed by a dense connective tissue of elastic and collagen fibers. This structure allows us to carry out various movements. In this case, our cover is not torn, but stretched. The deepest layer of the skin consists of dense connective tissue bundles, between which are scattered fat cells. Let's consider each of them separately in the perspective of the relationship between structure and functions.
Examining the skin under a microscope, you canto find out that its outer layer consists of two types of cells. The first - dead and keratinized. They fit tightly together, forming a stratum corneum. His cells are continuously peeling off. At the same time, the skin does not become thinner. What is the secret? Under the stratum corneum of the epidermis is a growth. His cells are constantly divided, providing regeneration processes - skin repair.
The epidermis also determines the color of the skin. In its cells there is a coloring substance - a pigment melanin. It is his education that causes summer sunburn.
The middle layer is called the skin or dermis. Examining the skin under a microscope, you can see that it is here that most of its elements are located. These include receptors. These are special sensitive formations, capable of perceiving pain, cold, heat, touch.
In the dermis are located and sebaceous glands thatgive off a special fat. It softens the skin and hair, prevents the ingress of harmful substances into the body. Sweat glands have the form of glomeruli, the straightened part of which opens outwards with a hole. Sweat consists of water with solutions of mineral salts and urea.
Follicles, or hair follicles are also locatedin the middle layer. They are braided by capillaries, through which food and gas exchange occurs. Each hair connects with the muscle that lifts it. This is noticeable in a stressful situation. Under the influence of the nervous system, the muscles contract, so "the hair stands on end". This reaction is called piloerection. It has a protective value, because it reduces heat transfer through the skin.
This layer of skin is the deepest and most massive. It is a kind of supply of nutrients. Their body uses during fasting as a reserve. Subcutaneous fat also participates in heat exchange, protecting the body from hypothermia. An important role is played by cellulose during mechanical damage. In everyday life, we do not notice this, but it is possible to step on the feet only thanks to a layer of subcutaneous fat. Do not believe me? And you try to pass on the knees, the cups of which do not have such protection. It will be difficult to do this because of the strong friction and pain.
So, the skin under the microscope is a unique structure. It is formed by an epithelial and connective tissue, which will consist of several layers: epidermis, dermis and skin. The structure of each of them corresponds to the functions performed.