Subcutaneous fatty tissue anatomical and physiological features. Anatomical and physiological features of the skin, subcutaneous fat tissue

Leather.In a child, especially in the 1st year of life, the skin has a number of morphological and functional features that largely distinguish it from the skin of adults. These differences make it possible to understand and explain the frequency of skin lesions and the characteristics of their course at an early age. A healthy child has smooth, velvety, pale pink skin. It is well supplied with blood due to the developed capillary network. The blood vessels are wide and easily permeable. The stratum corneum is thin and consists of 2-3 layers of loosely interconnected and constantly sloughing cells. The main (germinal) layer is well developed. This is associated with the high ability of the child’s skin to recover (regenerate). The dermis consists of papillary and reticular layers, in which the connective base and muscle fibers are developed. The basement membrane, located between the epidermis and the dermis, is represented by loose fiber and does not provide a strong connection to the main layers of the skin, which leads to easy separation of the epidermis and exposure of the dermis during skin diseases. Functions of the skin. Due to the morphological immaturity of its skin protective the function is insufficient - the skin is extremely vulnerable and prone to maceration, susceptible to the harmful effects of chemical irritants, easily infected, often serving as an entry point for infection. Therefore, when caring for a child, mothers and staff must observe the strictest cleanliness and asepsis, and avoid the use of ointments containing irritating and easily absorbed substances at an early age. Also imperfect thermoregulatory skin function. Due to the insufficient development of the thermoregulatory function of the central nervous system and the intense release of heat and moisture through the skin surface, children of the 1st year of life do not maintain a constant body temperature well: the child easily overheats or becomes hypothermic. Sweat glands are involved in thermoregulation of the body. However, in the first days of life, due to the immaturity of the sweating centers of the brain, they do not function, their ducts are poorly developed, and the lumens are closed by epithelial cells. Sweating begins at 3-4 months and appears at a higher temperature than in older children. Given the insufficient heat-regulating function of the skin, the child should be protected from both cooling and overheating. excretory The function of the skin is quite developed due to the thin epidermis, good blood circulation and the relatively large surface of the skin. Respiratory function of the skin at an early age is more significant than in adults. Full functioning of the skin as a respiratory organ can be ensured only with careful care of the child with regular hygienic baths. Vitamin synthesis occurs in the skin under the influence of ultraviolet rays D , which plays an important role in phosphorus-calcium metabolism, especially in children of the 1st year of life. For execution vitamin-forming functions, it is necessary to follow a daily routine with sufficient time for the child to spend time in the fresh air. The skin of a newborn is covered with vernix. It facilitates the passage of the child through the mother's birth canal and protects it from external influences. The lubricant contains the secretion of the sebaceous glands, which begin to function during fetal development. Significant secretion of the sebaceous glands during the newborn period can lead to the appearance of seborrhea (“baby cap”) on the scalp and whitish-yellow spots on the nose and cheeks. The hair on a newborn's head is usually well developed, but due to the lack of a core, the hair is very soft. After 6-8 weeks they fall out and are replaced by new ones. The thin vellus hair that covers the child's body in the first months of life is later replaced by permanent hair. Subcutaneous fat tissue. In full-term babies, it is well developed and grows rapidly in the first 6 months of life. In newborns it is better expressed on the cheeks, upper and lower extremities and worse on the stomach. The composition of fat in young children differs in chemical composition from fat in adults. It contains more solid fatty acids with a high melting point. As a result, the subcutaneous fat layer can become dense as the child cools and conditions such as sclerema and scleredema develop. The composition of adipose tissue depends not only on the age of the child, but also on its location. This explains the natural sequence in the accumulation and disappearance of fat as body weight increases or decreases. The subcutaneous fat layer first disappears on the abdomen, then on the torso, limbs, and last of all on the face. The increase in the mass of adipose tissue in the 1st year of life occurs due to an increase in the number of fat cells. Therefore, systematic overfeeding of infants can lead to persistent and severe obesity in the future.

The degree of development of subcutaneous fat is determined by palpation (palpation) and consists of measuring the thickness of the skin fold formed when the skin is grasped with the thumb and forefinger.

In the area of ​​the lower third of the shoulder along the back surface;

On the anterior abdominal wall at the level of the navel along the edge of the rectus abdominis muscles;

At the level of the angles of the shoulder blades;

At the level of the costal arches;

On the front of the thigh.

With a skin fold thickness of 1-2 cm, the development of the subcutaneous fat layer is considered normal, less than 1 cm - reduced, more than 2 cm - increased.

Attention is also paid to the nature of the distribution of the subcutaneous fat layer. Normally, it is distributed evenly (the thickness of the skin fold is almost the same in different parts of the body). If the subcutaneous fat layer is unevenly distributed, it is necessary to indicate the areas of increased fat deposition.

9. Edema: varieties according to origin and mechanism of development. Characteristics of cardiac and renal edema. Methods for detecting edema.

Edema is an excessive accumulation of fluid in body tissues and serous cavities, manifested by an increase in tissue volume or a decrease in the capacity of serous cavities and a disorder in the function of edematous tissues and organs.

Swelling can be local (local) or general (widespread).

There are several degrees of edema:

Hidden edema: not detected by examination and palpation, but detected by weighing the patient, monitoring his diuresis and the McClure-Aldrich test.

Pastiness: when pressing with a finger on the inner surface of the leg, a small pit remains, which is detected mainly by touch.

Explicit (pronounced) swelling: the defiguration of joints and tissues is clearly visible and when pressed with a finger, a clearly visible hole remains.

Massive, widespread edema (anasarca): accumulation of fluid not only in the subcutaneous fatty tissue of the torso and limbs, but also in the serous cavities (hydrothorax, ascites, hydropericardium).

The main reasons for the development of edematous syndrome:

1) increase in venous (hydrostatic) pressure - hydrodynamic edema;

2) decrease in oncotic (colloid-osmotic) pressure - hypoproteinemic edema;

3) disturbance of electrolyte metabolism;

4) damage to the capillary wall;

5) impaired lymphatic drainage;

6) drug-induced edema (minerolocorticoids, sex hormones, non-steroidal anti-inflammatory drugs);

7) endocrine edema (hypothyroidism).

Edema of cardiac origin. U In a patient with heart failure, edema is always localized symmetrically. First, swelling of the feet and ankles forms, which can completely disappear after a night's rest. Swelling increases towards the end of the day. As heart failure progresses, the legs and then the thighs swell. In bedridden patients, swelling of the lumbosacral region appears. The skin over the swelling is tense, cold, and cyanotic. The swelling is dense; when pressed with a finger, a hole remains. As heart failure progresses, ascites and hydrothorox may appear. Trophic changes in the skin in the shin area are often detected in the form of increased pigmentation, depletion, cracking, and the appearance of ulcers.

Edema of renal origin.

Renal edema is of two types:

1) nephritic edema - forms quickly and is localized mainly on the face, less often on the upper and lower extremities; First of all, tissues rich in blood vessels and loose fiber swell;

2) nephrotic edema is one of the manifestations of nephrotic syndrome, which is characterized by hypoproteinemia, dysproteinemia, hypoalbuminemia, hyperlipidemia, massive proteinuria (more than 3 g/day); nephrotic edema develops gradually, first the face swells after a night's rest, then the legs, lower back, and anterior abdominal wall swell; ascites, hydrothorax, and anasarca may occur.

Renal edema is pale, soft, dough-like, sometimes shiny, and easily movable.

Methods for detecting edema:

1) inspection;

2) palpation;

3) daily determination of body weight, measurement of diuresis and comparison with the volume of fluid consumed;

4) test for hydrophilicity of McClure-Aldrich tissues.

Technique and normal parameters of the test for tissue hydrophilicity: 0.2 ml of physiological NaCl solution is injected intradermally into the area of ​​the inner surface of the forearm. With a pronounced tendency to edema, the blister resolves within 30-40 minutes instead of 60-90 minutes normally.

Leather consists of epidermis and dermis. The epidermis has a very delicate, thin (from 2 - 3 layers of keratinized cells), constantly sloughing off epithelial and actively growing main (germinal) layers.

The dermis (the skin itself) consists of papillary and reticular layers, in which the connective tissue base and muscle fibers are very poorly developed. The basement membrane between the epidermis and dermis is represented by loose fiber. As a result, in newborns the epidermis is easily separated from the dermis (de-squamative erythroderma).

The skin of a newborn and infant is rich in blood vessels with a dense network of wide capillaries, which gives the skin a bright, then soft pink color. The sebaceous glands are well developed and function intensively already in utero, forming a cheesy lubricant that covers the child’s body at birth. The sweat glands are formed, but sweating begins at 3-4 months, which is due to the imperfection of the thermoregulation center.

The hair on a newborn's head falls out easily and is replaced several times during the first year of life. The shoulders and back are covered with fluff, which is more pronounced in premature babies.

The protective function of the skin is insufficient due to the very thin epidermis and rich blood supply. These same skin features ensure good respiratory function, which is necessary when hypoxia occurs.

The child does not regulate his heat exchange well and easily becomes overcooled or overheated. At 3 - 4 months, thermoregulation and excretory functions are normalized. The skin is involved in the formation of pigment and vitamin D3 under the influence of ultraviolet radiation.

Excessive skin irritation with poor care (wet, dirty diapers) can cause anxiety in the child, sleep disturbances and the subsequent formation of persistent inhibitory processes in the central nervous system, disruption of its neurotrophic function and the development of dystrophy.

Subcutaneous fatty cellulose(PZhK). Begins to form in the 5th month of intrauterine life. The composition of fatty acids in infants is similar to the composition of fats in human milk: a larger amount of solid (palmitic and stearic) acids and a smaller amount of liquid oleic acid. This creates the possibility of direct (bypassing digestion) utilization of fat from mother's milk. The predominance of the content of solid fatty acids also ensures a denser tissue turgor in children of the first year of life and a tendency to the formation of local compactions and swelling of the skin and subcutaneous fatty tissue (sclerema, scleredema of newborns). Brown (brown) adipose tissue is located in the tissue of the chest, mediastinum, around large vessels and internal organs. It provides a higher level of heat production in newborns. More fat is deposited on the face, where the fatty bodies of the cheeks (Bisha's bodies) contain a lot of solid fatty acids, on the buttocks, thighs, and abdomen (the content of liquid acids predominates here). Subcutaneous fat disappears first on the abdomen and chest, then on the limbs and lastly on the face.

Lymph nodes. Bookmark in the 2nd month of intrauterine life. From this time (and until the end of life), their hematopoietic function is carried out - the production of lymphocytes. The nodes develop up to 12 - 14 years of age, followed by involution during puberty. Lymph nodes consist of parenchymal (lymphoid) tissue with large sinuses and are limited by a very delicate and thin capsule. Elements of the reticular and connective tissue stroma of the node (trabeculae, septa) and capsule are practically absent. Insufficient differentiation of immunocompetent cells of the lymph nodes. For these reasons, aloho has a protective (barrier) function. At the age of 1 - 3 years, the lymph nodes are quite well developed and respond to the introduction of the pathogen with a local inflammatory reaction.

By the age of 12-13, the structure and function of the lymph nodes correspond to those of an adult. They delay and suppress the pathogenic flora that has penetrated into them without visible changes or by briefly increasing in size and subsequently normalizing.

The thickness of the various layers of skin in children under three years of age is 1.5-3 times less than in adults, and only by the age of 7 does it reach the level of an adult.

The epidermal cells in children are relatively far apart from each other, and its structure is loose. The stratum corneum in newborns is thin and consists of 2-3 layers of easily listenable cells. The granular layer is poorly developed, which determines the significant transparency of the skin of newborns and its pink color. The basal layer is well developed, but in the first months of life, due to the low function of melanocytes, the skin background is lighter.

A distinctive feature of the skin of children, especially newborns, is the weak connection of the epidermis with the dermis, which is primarily caused by the insufficient number and poor development of anchor fibers. In various diseases, the epidermis easily peels off from the dermis, which leads to the formation of blisters.

The surface of a newborn's skin is covered with a secretion with weak bactericidal activity, since its pH is close to neutral, but by the end of the first month of life the pH decreases significantly.

In the skin of newborns and children of the first year of life, a network of wide capillaries is well developed. Subsequently, the number of wide capillaries gradually decreases, and the number of long and narrow ones increases.

The nerve endings of the skin are not sufficiently developed at the time of birth, but are functionally sound and cause pain, tactile and temperature sensitivity.

The skin of a child in the first year of life, due to its structural features, biochemical composition and good vascularization, is soft, velvety and elastic. In general, it is thin, smooth, its surface is drier than that of adults, and is prone to peeling. The entire surface of the skin and hair is covered with a water-lipid layer, or mantle, which protects the skin from adverse environmental factors, slows down and prevents the absorption and effects of chemicals, serves as a site for the formation of provitamin D, and has antibacterial properties.

Sebaceous glands

The sebaceous glands begin to function in the prenatal period; their secretion forms a cheesy lubricant that covers the surface of the fetal skin. The lubricant protects the skin from the effects of amniotic fluid and facilitates the passage of the fetus through the birth canal.

The sebaceous glands function actively in the first year of life, then their secretion decreases, but increases again during puberty. In adolescents, they are often clogged with horny plugs, which leads to the development of acne.

Sweat glands

By the time of birth, eccrine sweat glands are not fully formed, their excretory ducts are underdeveloped and closed by epithelial cells. Sweating begins at 3-4 weeks of age. During the first 3-4 months, the glands do not function fully. In young children (up to 3 years of age), sweating occurs at a higher temperature than in older children. As the sweat glands, the autonomic nervous system, and the thermoregulation center in the brain mature, the sweating process improves and its threshold decreases. By 5-7 years, the glands are fully formed, and adequate sweating occurs at 7-8 years.

Apocrine sweat glands begin to function only with the onset of puberty.

Primary hair is replaced by vellus hair before or shortly after birth (with the exception of eyebrows, eyelashes and scalp). The hair of full-term newborns does not have a core, and the hair follicle is not developed enough, which does not allow the formation of a boil with a purulent core. The skin, especially on the shoulders and back, is covered with vellus hair (lanugo), which is much more noticeable in premature babies.

Eyebrows and eyelashes are poorly developed, but their growth intensifies later. Hair development completes during puberty.

The nails of full-term newborns are well developed and reach the tips of the fingers. In the first days of life, nail growth is temporarily delayed and a so-called physiological feature is formed on the nail plate. At the 3rd month of life, it reaches the free edge of the nail.

SKIN RESEARCH METHOD

To assess the condition of the skin, questioning, examination, palpation and special tests are carried out.

INQUIRY AND INSPECTION

Whenever possible, the child is examined in natural daylight. The skin is examined sequentially from top to bottom: scalp, neck, natural folds, groin and buttock areas, palms, soles, interdigital spaces. During the examination they evaluate:

Skin color and its uniformity;

Humidity;

Cleanliness (no rashes or other pathological elements, such as peeling, scratching, hemorrhages);

The state of the vascular system of the skin, in particular the localization and severity of the venous pattern;

Integrity of the skin;

Condition of skin appendages (hair and nails).

Skin rashes

Skin rashes (morphological elements) can affect various layers of the skin, as well as its appendages (sweat and sebaceous glands, hair follicles).

Primary morphological elements appear on unchanged skin. They are divided into cavitary (spot, papule, node, etc.) and cavitary with serous, hemorrhagic or purulent contents (vesicle, bladder, abscess) (Table 5-3, Fig. 5-2-5-P).

The color of the skin depends on its thickness and transparency, the amount of normal and pathological pigments it contains, the degree of development, the depth and plethora of skin vessels, the content of lib and unit volume of crop and the degree of saturation of lib with oxygen. Depending on race and ethnicity, a child's normal skin color may be pale pink or varying shades of yellow, red, brown, and black. Pathological changes in skin color in children include pallor, hyperemia, and nianosis. jaundice and pigmentation

The moisture content of the skin is indicated by its shine: normally the surface of the skin is moderately shiny, with high humidity the skin is very shiny and often covered with drops of sweat: excessively dry skin is matte, rough

If pathological elements are detected on the skin, it is necessary to clarify;

Time of their appearance;

connection with any factors (food, medicinal, chemical, etc.):

The existence of similar symptoms in the past, their evolution (and changes in skin color and the nature of the rash):

Morphological type (see below):

Size (in millimeters or centimeters):

Number of elements (single elements, light rash, the elements of which can be counted upon examination, abundant - multiple elements that cannot be counted):

Shape (round, oval, irregular, star-shaped, ring-shaped, etc.):

Color (for example, during inflammation, ischemia occurs);

Localization and prevalence (indicate all parts of the body that have a rash, predominantly the head, torso, flexor or extensor surfaces of the extremities, skin folds, etc.):

Skin background in the area of ​​the rash (for example, hyperemic):

Stages and dynamics of development of rash elements: - features of secondary elements remaining after

fading of the rash (peeling, hyper- or gynopigmentation, crusts and etc.)

Secondary morphological elements appear as a result of the evolution of primary ones (Table 5-4).

Condition of skin appendages

When examining the hair, pay attention to the uniformity of growth, I determine! correspondence of the degree of hair development and its distribution on the body to the age and gender of the child. Assess the appearance of the hair (it should be shiny with straight ends) and the condition of the scalp.

When examining nails, pay attention to the shape, color, transparency, thickness and integrity of the nail plates. Healthy nails are pink in color, have smooth surfaces and edges, and adhere tightly to the nail bed. The periungual ridge should not be hyperemphasized and painful.

PALPATION

Palpation of the skin is carried out sequentially from top to bottom, and in areas of damage - with extreme caution. Humidity, temperature and elasticity of the skin are assessed.

Humidity is determined by stroking the skin of symmetrical areas of the body, including the skin of the palms, feet, armpits and groin areas.

5.2. SUBCUTANEOUS ADIPOSE FIBER

Adipose tissue consists predominantly of white fat, found in many tissues, and a small amount of brown fat (in adults, located in the mediastinum, along the aorta and under the skin in the interscapular area). In brown fat cells there is a natural mechanism for uncoupling oxidative phosphorylation: the energy released during the hydrolysis of triglycerides and the metabolism of fatty acids is not used for the synthesis of adenosine triphosphate, but is converted into heat.

ANAT0M0-PHYSI0L0GICAL FEATURES OF SUBCUTANEOUS ADIPOSE FIBER

At the end of the prenatal period and in the first year of life, the mass of adipose tissue increases as a result of an increase in both the number and size of fat cells (by 9 months of life, the mass of one cell increases 5 times). The thickness of subcutaneous fat increases noticeably from birth to 9 months, and then gradually decreases (by the age of 5, on average, it decreases by 2 times). The smallest thickness is noted at 6-9 years.

During puberty, the thickness of the subcutaneous fat layer increases again. In teenage girls, up to 70% of the fat is located in the subcutaneous tissue (which gives them a round shape), while in boys the subcutaneous layer accounts for only 50% of the total fat.

TECHNIQUE FOR STUDYING SUBSCUTANEOUS ADIPOSE FIBER

The condition of subcutaneous fat is assessed by inspection and palpation.

DEGREE OF DEVELOPMENT

The degree of development of subcutaneous fatty tissue is assessed by the thickness of the skin fold, measured in various parts of the body (Fig. 5-40):

On the stomach;

On the chest (at the edge of the sternum);

On the back (under the shoulder blades);

On the limbs.

For an approximate practical assessment, you can limit yourself to studying 1-2 folds.

Submitted by A.F. Tura, the average thickness of the fold on the abdomen is:

In newborns - 0.6 cm;

At 6 months - 1.3 cm;

At 1 year - 1.5 cm;

At 2-3 years - 0.8 cm;

At 4-9 years old - 0.7 cm;

At 10-15 years old - 0.8 cm.

Lymph nodes are oval formations of various sizes, located in groups at the confluence of large lymphatic vessels.

Axillary lymph nodes are located in the axillary fossae and collect lymph from the skin of the upper limb (with the exception of 111. IV and V fingers and the inner surface of the hand).

Thoracic lymph nodes are located medially from the anterior axillary line under the lower edge of the pectoralis major muscle; they collect lymph from the skin of the chest, from the parietal pleura, partly from the lungs and from the mammary glands.

The ulnar (cubital) lymph nodes are located in the philtrum of the biceps mouse. Collect lymph from II I. IV. V fingers and inner surface of the hand.

Inguinal lymph nodes are located along the inguinal ligament and collect lymph from the skin of the lower extremities, lower part and abdomen, buttocks, perineum, genitals and anus.

The popliteal lymph nodes are located in the popliteal fossae and collect lymph from the skin of the foot.

Research methodology

Questioning reveals:

Increased size of lymph nodes;

The appearance of pain and redness in the area of ​​the lymph nodes;

How long ago these complaints appeared;

Possible causes preceding the appearance of these complaints (infections and other provoking factors);

Concomitant conditions (presence of fever, weight loss, symptoms of intoxication, etc.).

The examination reveals:

Significantly enlarged lymph nodes;

Signs of inflammation are skin hyperemia and swelling of the subcutaneous fat tissue above the lymph node.

Palpation allows you to evaluate the characteristic changes in the lymph nodes.

* Size of lymph nodes. Normally, the diameter of the lymph node is 0.3-0.5 cm (the size of a pea). There are six degrees of lymph node enlargement:

Grade I - lymph node the size of a millet grain;

Degree )