Anatomo-physiological features of skin, subcutaneous fatty layer, muscular and skeletal system. associate professor Kantemirova M.G.

Features of the skin of newborns : Insufficient pigment synthesis and the lack of keratohyoline – more pale skin Thin epidermis with poor developed corneum (horny) and spinosum layer Basal membrane is not well developed and can separate easily. The ph of the newborn’s skin is near neutral. Derma is not well developed, it’s structure is predominately cellular, fibers not enough developed. Derma can traumatized easily. Respiratory function are completely developed in newborns and higher than in adults Absorptive function is higher than in adults Excretory function are not completely developed Thermoregulation is poor, newborns are prone to over cooling and overheating Protective function are poor developed The skin in newborns is dryer than in adults Sensitive function are completely developed in newborns

Frequent skin changes in newborns Physiological jaundice Erythema neonatorum Erythema toxicum Peeling of skin Mongolian blue spots Milia Mottled skin

Primary lesions Macules – flat, nonpalpable areas of color change of skin (café-au- lait sports, vitiligo, mongolian spots …) Papules – raised skin lesions of less than 0,5 cm in diameter Nodules – elevated skin lesions larger than 0,5 cm in diameter Plaques – well-circumscribed, broad-based lesions often formed by coalescence of number of papules (psoriasis) Vesicle – elevated skin lesions, fluid containing of <1 cm diameters (chicken pox) Bullae – vesicle larger than 1 cm Pustules – vesicles with purulent content or pus (pyoderma) Purpura – hemorrhagic rash, cannot be blanched by pressure with a finger (petechiae, ecchymoses, ecchymotic elevated skin patches)

Secondary lesions Scales shedding of excess of normal and abnormal horny layer of skin Crusts Excoriations – linear losses of skin due to scrathing Ulcers (vascular insufficiency or burn) Fissures – linear clefts deep in thickened or inflamed skin Lichenification - thickening of skin with exaggeration of skin markings (allergic, infective) due to chronic rubbing Atrophy Eczematous skin lesions – inflammatory lesion witn erythema and vesiculation, than –scaling, crusting, lichenification Hyperkeratosis

Skin appendages in newborns The presence of lanugo Full term newborn’s nails rich the edge of the distal phalanx Sebaceous glands are well developed and function except ones on the palms and soles Sweat glands developed well except for the excretory ducts, so not functioning well

FEATURES OF THE SUBCUTANEOUS FATTY LAYER IN INFANTS The fat cells are small and contain the nuclei. The amount of subcutaneous fat relatively more than in adults. There are almost no accumulation of fatty tissue in the cavities. The preservation of sites of the embryonic adipose tissue (extramedullary hematopoiesis). The presence of brown fat. The predominance of refractory fat

Features of muscular system Skeletal muscle in the newborn anatomically shaped and well developed. Muscle mass is much smaller than an adult. By age 15 years muscle mass is 32-33% (40-44% of adults) Muscles in infants thinner and weaker, muscle surface is smoother, more distinct in years. Fascia in neonates is thin, friable, easily separated from the muscle. Poor development of the tendon and weak connection with periosteum of the cranial bones - predispose to the formation of hematomas in childbirth. Skeletal muscle in infants have fewer contractile proteins, the presence of fetal forms of myosin. At the prenatal period- low excitability of skeletal muscle. Newborn muscles do not relax, even during sleep ( the muscles takes part in heat production, metabolic exchanges, stimulation of muscle tissue) The muscles of the trunk are better developed The prevalence of flexor muscles tone. A large number of nuclei.

Primary teeth erupt from 6 months. For an approximate determination of the number of teeth in a given age we can use the following formula: x = n - 4, where x - the number of milk (primary) teeth, n - the child's age in months. Change of milk teeth to permanent starts with years. To determine the approximate number of the permanent teeth - use the formula x = 4n - 20, where x - the number of permanent teeth n - number of child’s years,..,