The integumentary system of a person is the organs that form the inner and outer protective shell of his body. The largest of the human organs has a surprisingly complex structure.
The human integumentary system: structure and functions
Skin is the outer layer of the body that protects it from moisture loss, infection and mechanical shock. Its surface area averages 1.7 m2. The skin is not just a boundary between the external and internal environment, it is a full-fledged organ. Human life and he alth directly depend on its proper functioning.
Skin structure
The epidermis is the very first outer layer of the skin. Consists of stratified epithelium. The cells of the inner part of the epithelium are constantly dividing and multiplying, while the cells of the outer part become keratinized and fall off. This process is continuous, leading to a complete renewal of the stratum corneum every week. The melanin pigment from the inner layer of the epidermis determines skin color.
The epidermis borders on the dermis with a thin plate - the basement membrane. The outer papillary layer forms visible protrusions and grooves on the skin. Here are the openings of the glands, from which sweat flows along the grooves and moisturizes the skin. It is with the help of the dermis that the human integumentary system forms on the palms andthe soles of the feet have an individual pattern that does not repeat or change over time.
For elastic, elastic and dense skin meets the mesh layer, consisting of bundles of elastic, collagen and muscle fibers. This layer of skin contains hair roots and glands (sebaceous and sweat glands).
Subcutaneous base - loose connective tissue with fatty deposits. Their volumes depend on many factors:
- age;
- gender;
- body features;
- heredity;
- lifestyle;
- diet;
- physical activity.
The subcutaneous tissue with adipose tissue does not conduct heat well, so very thin people get cold more often than full ones.
Secret glands
Sweat, mammary and sebaceous glands are derivatives of the skin. The integumentary system can contain up to 3 million sweat glands! Under normal conditions, they produce a little more than half a liter of sweat, at elevated external temperatures or active physical work - up to 3. Water makes up most of the sweat (98%), the remaining 2% is ammonia, urea, s alts, uric acid, etc.
The sebaceous glands are distributed over almost the entire surface of the human body, except for the soles of the feet and palms. Their concentration is especially high in the area of the face and head. The ducts carry sebum, which consists of wax, fat and hydrocarbon, directly into the hair follicles.
Nails and hair
Nails are special cells of the epidermis, formed into a hard plate that protects the ends of the fingers and toes. They grow slowly, and the speed does not change throughout life. The uniform pink color of the nail indicates its proper nutrition and blood supply. When changing color, you should review your daily menu, enrich it with vitamins and minerals.
Hair covers the most vulnerable parts of the human body with keratinized fibers of epidermal cells. Hair is made up of a medulla, cortex, and sheath. The cortical layer contains pigments that are responsible for the shade of the hair. Hair follicles containing roots are buried deep in the dermis. All hair follicles are formed in the womb. New bulbs in the process of life are not formed. The process of hair growth is undulating. The stage of active growth is replaced by rest, and vice versa. The average human hair growth rate is 0.1-0.3 mm per day.
The main functions of the skin and its derivatives
This is where the receptors responsible for touch and other response functions are located.
- Protection is the first and main function for which the entire human integumentary system functions. The organs are closed from any external influence by a reliable shield. Nerve endings on the skin warn of danger. It is they who make us jerk our hand sharply after touching boiling water. Mechanoreceptors are sensitive to touch, pressure, and vibration. Thermoreceptors protect us from hypothermia and frostbite. Nocireceptors are responsible for pain sensation. Adipose tissue protects internal organs from severe mechanical damage. Melanin formed in the basal layerskin under the influence of ultraviolet light, protects the deepest structures of the skin.
- Temperature control. Maintaining optimal body temperature is carried out by the skin in many ways: sweating, constriction and expansion of blood vessels, accumulation of fat layer, goosebumps.
- Absorption. The integumentary system has the ability to absorb moisture. Various substances in the form of molecules enter the epidermis and through the blood vessels enter the human blood. Thanks to this opportunity, a person actively uses creams, gels, masks, balms.
- Select. Often the body urgently needs to get rid of unwanted substances, the human integumentary system helps it in this. Secretory organs are able to remove them from the body to the surface of the epidermis along with sweat. And sebum, secreted by the sebaceous glands, moisturizes, lubricates the skin and hairline, maintains its he althy appearance.
- Production of vitamin D. It is formed when exposed to sunlight on the skin, through the blood vessels enters the bloodstream. Vitamin D is necessary for the body to maintain the normal functioning of the skeletal system. It helps calcium to be absorbed in the body in the right amounts. Strong bones are the foundation of any he althy body.
Human integumentary system - age features
The most noticeable age-related feature of a person is a change in hair color to light. This is because with age, the hair follicle produces less melanin. Hair whitens firstcover on the temples, gradually gray hair spreads over the entire head, then throughout the body. No drugs, vitamins, supplements can stop the process if it is already running.
Over time, the appearance of nails also changes a lot. They lose their transparency and elasticity, become hard, brittle and dull.
After 30, all skin structures undergo changes:
- elastic fibers break down;
- appears dryness, feeling of tightness;
- wrinkles are getting deeper and more noticeable;
- skin increasingly thin and irritable.
The integumentary system does not change immediately, it is a long physiological process that is irreversible. You can only temporarily stop its external manifestations by carefully caring for your skin:
- avoid direct sunlight;
- don't take a bath for too long;
- do not use regular powder, foundation;
- moisturize the epidermis with creams, tonics, lotions, masks.
And then your skin will delight for a long time with its he althy and blooming appearance.
