Does the skin have protective function?

Does the skin have protective function?

Does the skin have protective function? There are three kinds of skin: white, yellow and black, and the structure of human skin is the same. The average person's skin is composed of epidermis, dermis and subcutaneous tissue, so it is very important to maintain the stratum corneum. So does the skin have a protective function?

Does the skin have protective function? 1 Skin has a protective function and has many functions:

1, the skin has barrier function. The skin has certain elasticity and can resist the impact and extrusion of external forces. The structure of skin also has a certain protective effect on the damage of physical effects such as current and light. The skin surface is weakly acidic and has a certain buffering ability to acid and alkali.

The dense structure of epidermis also has protective effect on biological damage. In addition, the stratum corneum of the skin has the property of semi-permeable membrane, which can prevent the loss of nutrients and electrolytes in the body.

2, the skin can absorb substances through the stratum corneum, sebaceous glands of hair follicles and sweat glands, and has the absorption function.

3, the skin can feel cold, warm, painful, itchy, tactile and other feelings.

4. The eccrine glands, apocrine glands, sebaceous glands and other appendages of the skin all have the functions of secretion and excretion.

5. The skin can transmit the information of ambient temperature to the center through the temperature sensor, and can also be used as an effector of body temperature to regulate body temperature.

6. Skin participates in the metabolism of sugar, protein, lipid, water and electrolyte, and melanin.

7. The skin also has important immune function.

Does the skin have protective function? 1. Protection function

Skin covers the surface of the body and is the natural protective barrier of the human body. The stratum corneum in the skin can prevent the loss of nutrients and water in the body and prevent the invasion of various harmful substances; The soft anti-fat layer can effectively buffer the impact of external mechanical forces, thus protecting the human body. In addition, the pigment cells in the skin can absorb ultraviolet rays and protect the human body from the sun.

Second, sensory function.

We have different feelings, such as "pain, touch, cold, heat, pressure and itching", which come from many nerve endings in the skin. When environmental changes or external stimuli have adverse effects on the body, these feelings are like the early warning mechanism of the body, reminding us to take timely measures to prevent all kinds of violations.

Third, the thermoregulatory function.

The fat layer in the skin plays an important role in maintaining body temperature. Moreover, the skin can also dissipate heat through the contraction and expansion of capillaries, the reduction and increase of sweat secretion, and physical means such as conduction and evaporation, so as to adjust the body temperature to adapt to the changes of external temperature.

Four, absorption, secretion and excretion function

Skin is not an absolute barrier that is completely impermeable, but also has the functions of absorption, secretion and excretion. Some water, fat-soluble substances, heavy metals (such as mercury, lead, arsenic, copper, etc. ) and salts can enter the body through pores, sweat pores, sebaceous pores and epidermal cell gaps.

Sweat secretion and sebum excretion can not only excrete waste in human body, but also form an emulsified skin film on the skin surface after mixing them, which can moisturize the stratum corneum and prevent chapped skin.

Verb (abbreviation of verb) immune function

Skin is the largest immune organ of human body, which contains a variety of immune cells and immune factors. It is also the starting organ of human immune response and the place where immune effects are carried out. Skin can protect human body from foreign pathogens, and identifying, labeling and killing abnormal cells and aging cells is also very important for human health.

Does the skin have protective function? Human skin is divided into epidermis and dermis, which has the functions of protection, feeling, secretion, excretion and breathing.

First, the epidermis

Epidermis is the outermost layer of skin, with an average thickness of 0.2 mm. According to the different development stages and morphological characteristics of cells, it can be divided into five layers from outside to inside.

1, stratum corneum: composed of several layers of keratinocytes, containing keratin. It can resist friction and prevent body fluids from leaking out and chemicals from invading. Keratin has strong water absorption, and the water content is generally not lower than 10% to maintain the softness of skin. If it is lower than this value, the skin will be dry and scaly or chapped.

2. Transparent layer: It consists of 2-3 layers of flat transparent cells, the nucleus disappears and contains keratin. It can prevent the penetration of water, electrolyte and chemicals, so it is also called barrier zone.

3. Granular layer: composed of 2-4 layers of flat spindle cells, containing a large number of basophilic transparent keratinocytes. When spindle cells in granular layer increase, it is called granular layer hypertrophy, which is often accompanied by hyperkeratosis; The granular layer disappears, often accompanied by poor keratinization.

4. Spine cell layer: It consists of 4-8 layers of polygonal spines, which gradually flatten from bottom to top, and cells are connected with each other through desmosomes, forming a so-called intercellular bridge.

5. Basal layer: It consists of a layer of columnar cells arranged in a grid. The cells in this layer divide constantly, move up gradually, keratinize and deform to form other layers of epidermis, and finally keratinize and fall off. There is a kind of melanocyte from neural crest between basal cells, accounting for 4% ~ 10% of the whole basal cells, which can produce melanin and determine the depth of skin color.

Second, the dermis, derived from mesodermal leaves, consists of fibers, matrix and cells.

1, fiber: collagen fiber, elastic fiber and reticular fiber. Collagen fibers are the main components of dermis, accounting for about 95%, and they are assembled into bundles. In addition to giving skin elasticity, it also constitutes a scaffold for skin and its appendages.

2. Matrix: It is an amorphous and uniform colloidal substance filled between fiber bundles and cells, which provides material support for various skin components and places for substance metabolism.

3. Cells: mainly fibroblasts, which can produce collagen fibers, elastic fibers and matrix; Tissue cells are a part of reticuloendothelial system, which have the ability to devour microorganisms, metabolites, pigment particles and foreign bodies, and play an effective role in removing them.

Mast cells exist in dermis and subcutaneous tissue, and the number of mast cells is the largest in dermal papillary layer. The granules in its cytoplasm can store and release histamine and heparin.

Acne and the like, if caught by hand, are prone to secondary infection, and if the skin is infected to the epidermis, it generally does not scar; If it is infected with dermis, it may scar.

Does the skin have protective function? Skin has five basic functions: protecting, regulating body temperature, feeling, excreting and absorbing.

1, protection function

Skin is like a tough impermeable membrane, full of elasticity and tension, which completely covers the body surface, playing a good barrier role and protecting the body from various external injuries, including physical, mechanical, chemical, biological and other external injuries.

Under normal circumstances, our skin is weakly acidic, which can help prevent bacteria and viruses from multiplying on the body surface. The cuticle of the outer skin can also prevent excessive evaporation and distribution of water, protect the skin from being too dry due to water loss, and thus keep the skin moist. At the same time, the cuticle can resist the erosion of weak acids and bases and prevent the penetration of chemicals and water.

2, the function of regulating body temperature

The human body can maintain a constant temperature of about 37℃, mainly by the adjustment of the skin. When the outside temperature is high, the skin blood vessels dilate, and sweat glands secrete a lot of sweat to prevent the body temperature from rising with the outside temperature; When the outside temperature is low, the skin blood vessels contract and sweat secretion decreases, thus preventing the body from emitting heat and maintaining a constant temperature.

3. Sensory function

The body feels various external stimuli through the sensory function of the skin. There are abundant sensory nerve endings in the dermis of the skin, which can accept cold sensation, warm sensation, tactile sensation, pain sensation, pressure sensation and various compound sensations such as body, wet, dry, soft and hard. In addition, the skin can also produce a variety of nerve reflexes to protect the body from harm.

4. Excretion function

There are sweat glands and sebaceous glands on the skin, and excretion mainly plays a role through them. Sweat glands function like kidneys, which can excrete water and metabolic wastes in the body; Sebaceous glands secrete sebum, and fatty acids in sebum have bactericidal effect, and also have the functions of forming sebum film and lubricating skin and hair.

5, absorption function

The skin completes the absorption function through pores. The intact skin is impermeable to water, but lipid-like solutes can be selectively absorbed, and the main way of absorption is pores, which is why many drugs and cosmetics can be absorbed through the skin.

However, once the pores are blocked and inflamed, skin problems such as blackheads, acne, and closed mouths will be formed, and even the pores are large, resulting in the skin being unable to absorb nutrients.

Many fairies choose mud film when solving the problem of how to clean up clogged pores. Indeed, many mud films have the function of adsorbing oil, and some mud films also have the function of exfoliating, which is naturally a good choice for cleaning pores.

However, it should be noted that the mud film is both absorbent and irritating, so fairies should control the frequency of using the mud film. Generally speaking, once or twice a week can fully meet daily needs.