The integumentary system of man

The integumentary system of a person is the organs that form the inner and outer protective shell of his body. The largest of human organs has a surprisingly complex structure.

The integumentary system of man: the structure and functions

Skin is an outer layer of the body that protects it from loss of moisture, infection and mechanical shock. The area of its surface is on average 1.7 m ² . Skin is not just a boundary separating the external and internal environment, it is a full-fledged organ. Its life and health directly depend on its proper functioning.

Skin Structure

The epidermis is the very first outer layer of the skin. It consists of a multilayered epithelium. The cells of the inner part of the epithelium are constantly divided and multiply, and the outer cells become cornified and fall off. This process is continuous, leading to a complete renewal of the horny layer every week. Pigment melanin from the inner layer of the epidermis determines the skin color.

The epidermis borders on the dermis with a thin plate - the basal membrane. The outer papillary layer forms visible protrusions and furrows on the skin. There are holes in the glands, from which sweat flows along the grooves and moistens the skin. It is with the help of the dermis that the human integumentary system forms on the palms and soles of the feet an individual pattern that does not repeat and does not change over time.

For the elastic, elastic and dense skin meets the reticular layer, consisting of bundles of elastic, collagen and muscle fibers. In this layer of skin, hair roots and glands (sebaceous and sweat) are located.

The subcutaneous base is a loose connective tissue with fatty deposits. Their volumes depend on many factors:

• age;
• floor;
• Features of the body;
• heredity;
• Lifestyle;
• Ration;
• physical exercise.

The subcutaneous tissue with fatty tissue does not conduct heat well, therefore very thin people freeze more often full.

Secret glands

Sweat, dairy and sebaceous glands are skin derivatives. The integumentary system can contain up to 3 million sweat glands! Under normal conditions, they produce slightly more than a half-liter of sweat, with increased external temperature or active physical work-up to 3. Water makes up the bulk of sweat (98%), the remaining 2% - ammonia, urea, salts, uric acid, etc.

The sebaceous glands are distributed almost over the entire surface of the human body, except for the sole of the feet and palms. Their concentration in the area of face and head is especially high. The ducts excrete sebum consisting of wax, fat and hydrocarbon, directly into the hair follicles.

Nails and hair

Nails are special cells of the epidermis, formed into a solid plate, protecting the end of the fingers on the hands and feet. They grow slowly, and the speed does not change throughout life. Even pink color of the nail speaks about its high-grade nourishment and blood supply. When changing the color, you should revise 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 consists of a cerebral, cortical substance and a membrane. In the cortical layer, pigments, responsible for the hue of the hair, are laid. Hair follicles containing roots are deeply embedded in the dermis. All the hair follicles are formed in the womb of the mother. New bulbs in the process of life are not formed. The process of hair growth is wavy. The stage of active growth is replaced by rest, and vice versa. The average growth rate of a human hair is 0.1-0.3 mm per day.

Basic functions of the skin and its derivatives

It is here that the receptors responsible for touch and other response functions are located.

1. Protection is the first and basic function for the sake of 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 sharply pull back our hand after touching the boiling water. Mechanoreceptors are sensitive to touch, pressure and vibration. Thermoreceptors protect us from hypothermia and frostbite. Nociceptors are responsible for pain. Fatty tissue protects internal organs from severe mechanical damage. Melanin, formed in the basal layer of the skin under the influence of ultraviolet, protects the deepest structure of the skin.
2. Thermoregulation. Support for optimal body temperature is carried out by the skin in a variety of ways: sweating, narrowing and widening of blood vessels, accumulation of the fat layer, goosebumps.
3. Absorption. The integumentary system has the ability to absorb moisture. Various substances in the form of molecules enter the epidermis and enter the bloodstream through blood vessels. Thanks to this opportunity, people actively use creams, gels, masks, balms.
4. Allocation. Often the body needs to get rid of unwanted substances urgently, the human integument helps it. Secret organs are able to remove them from the body to the surface of the epidermis, together with sweat. And sebum, separated by sebaceous glands, moisturizes, lubricates the skin and hair, maintains its healthy appearance.
5. The production of vitamin D. It is formed when exposed to sunlight on the skin, through the blood vessels enters the blood. 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 quantities. Strong bones - the basis of any healthy body.

The human integumentary system - the age features

The most noticeable age feature of a person is a change in the color of the hair to light. This is due to the fact that with age, the hair follicle produces less melanin. The first white hair on the temples, gradually graying spreads throughout the head, and then throughout the body. No medicine, vitamins, supplements can stop the process if it is already running.

Over time, the appearance of the nails also varies greatly. They lose their transparency and elasticity, they become rigid, brittle and dull.

After 30 years, all skin structures undergo changes:

• Elastic fibers are destroyed;
• There is dryness, a feeling of tightness;
• Wrinkles become deeper and more noticeable;
• The skin is more and more delicate and irritable.

The integumentary system does not change immediately, it is a long-term physiological process that is irreversible. You can only temporarily suspend its external manifestations, carefully caring for your skin:

• Avoid direct sunlight;
• Do not take a bath too long;
• Do not use regular powder, tonal remedies;
• Moisten the epidermis with creams, tonics, lotions, masks.

And then your skin will be happy for a long time with its healthy and blooming appearance.