Anatomical and physiological features of term infants

Leather. Delicate, velvety to the touch, elastic, pink, there may be remnants of gun hair on the back and shoulder girdle. Its richness with blood vessels and capillaries, weak development of sweat glands and active sebaceous activity lead to rapid overheating or hypothermia of the child. He has an easily injured skin, which is also important to take into account. With improper care, there is diaper rash, pores easily penetrate infection and pustules develop. On the occiput, upper eyelids, between the eyebrows may be cyanotic or reddish-colored stains caused by vasodilation (telangiectasia), or pinpoint hemorrhages. Sometimes on the wings and back of the nose there are yellowish-white nodules (milia). All these phenomena disappear in the first months of life. In the region of the sacrum, there may also be an accumulation of skin pigment, "Mongolian spot". It remains noticeable for a long time, sometimes all life, however it is not a sign of any violations. Hair of a newborn is up to 2 cm in length, eyebrows and eyelashes are almost invisible, fingernails reach the fingertips.
Subcutaneous fatty tissue. Well developed, more dense than it will be in the future - in terms of the chemical composition it is now dominated by refractory fatty acids.
Bone system. Contains a few salts, giving it strength, so the bones easily bend when improper care of the child.
Infantional feature - the presence in the skull of the neocoenous areas - the so-called. Fontanel. Large, in the form of a diamond, is located in the area of ​​the connection of the parietal and frontal bones, the size is 1.8-2.6 x 2-3 cm. Small, in the form of a triangle, is located at the point of convergence of parietal and occipital bones and most children are closed at birth . Such a soft connection of the bones of the skull is of practical importance when the head passes through narrow generic pathways. Its regular deformation into an elongated "pear" is not terrible and should not cause "panic". The right outlines are a matter of time. Do not scare the parents and the conspicuous disproportion of the parts of the baby's body. Indeed, the head looks too large, because 1-2 cm more than the circumference of the chest, the arms are much longer than the legs. The existing disproportion is also a matter of time, which will correct everything.
The thorax is barrel-shaped: the ribs are arranged horizontally, not obliquely, as in the future. They consist mainly of cartilage, as well as the spine, which does not yet have physiological curves. They will have to be formed later, when the child starts to sit and stand.
Muscular system. Most of their increased tone - the arms are bent at the elbows, the legs are pressed to the stomach: the posture is uterine by the remaining inertia. The neck does not hold a head - its muscles are not strong. Handles and legs of the child "bitch" continuously, but purposeful movements and motor skills will come with the maturity of the nervous system.
Respiratory system. Mucous membranes of the respiratory tract are tender, contain more blood vessels, therefore, with infections, more often viral, swelling develops quickly, a large amount of mucus is released, which makes breathing very difficult. He is impeded by the anatomical narrowness of the nasal passages of the newborn, as well as of his trachea (respiratory throat) and bronchi. The auditory, or eustachian, tube is wider than in children older than age, which facilitates the penetration of infection and the development of otitis media (inflammation of the middle ear). But there is never an inflammation of the frontal sinus (frontitis) and the maxillary, or maxillary sinus (sinusitis), tk. They are still absent. The lungs are not sufficiently developed, the respiration is superficial and is mainly due to the diaphragm - the muscle located on the border of the thoracic and abdominal cavities. Therefore, respiration is easily disturbed by the accumulation of gases in the stomach and intestines, constipation, tugom swaddling, pushing the diaphragm upward. Hence the desire - to monitor the regular emptying of the intestine, not swaddling the child too tight.
Since, with its shallow breathing, the infant does not receive enough oxygen, he breathes often. The norm is 40-60 breaths-exhalations per minute, but this frequency increases even with insignificant load. Therefore, pay attention first of all to shortness of breath, which is accompanied by a feeling of lack of air and may be a sign of the disease.
The cardiovascular system. With the birth of the newborn changes in the circulatory system, initially functional - umbilical vessels and the vein stop their activity, and then the anatomical ones - the intrauterine channels of the blood flow are closed. With the first breath, a small circle of blood circulation is included in the work, passing through which the blood is saturated in the lung tissue with oxygen.
The pulse rate is 120-140 beats per minute, with feeding or crying increases to 160-200 beats. Arterial pressure at the beginning of the first month 66/36 mm Hg. St., And by the end of it - 80/45 mm Hg. Art.
The digestive system: immature in a functional sense, and as the metabolism is increased in newborns, it carries a heavy load - slight errors in the diet of the mother breastfeeding and the baby's diet can induce indigestion (dyspepsia).
The mucous membrane of the mouth is rich in blood vessels, thin, tender, easily vulnerable.
The language is big. On the mucous membrane of the lips there are so called. "Cushions" - small whitish elevations, separated by strips, perpendicular to the long lip (Palfundler-Lushka cushions); The mucosa forms a fold along the gums (Roben-Majito fold); Elasticity of the cheeks impart a so-called. Bisch lumps are the accumulations of adipose tissue located in the thickness of the cheeks. They are available both in healthy and in those born with hypotrophy - eating disorder, accompanied by a decrease in body weight. With the transition of hypotrophy into a severe form, the body loses almost all the fatty tissue, except Bishu's lumps. Digestive glands, including salivary glands, have not yet developed: very few saliva are released in the first days.
Muscles that block the entrance from the esophagus into the stomach are also underdeveloped - this leads to frequent ungovernable regurgitation. To prevent it from feeding, you need to hold the child for about 20 minutes on your hands, vertically, leaning against your chest. Initially, the stomach holds about 10 ml of liquid, by the end of the first month its capacity increases to 90-100 ml.
The muscles of the intestine are still little trained and the progress of food on it is slowed down.
Therefore, newborns are so tormented by accumulations of gases formed during the digestion of milk and bloating - flatulence.
There are often constipation. Stool in the first 1-3 days of life (called "meconium") have a characteristic viscous consistency of a dark green color, there is practically no smell. Meconium is formed from amniotic fluid, mucus, bile, which enter the stomach and 1 intestine of the fetus. According to the presence of these secretions in the first hours after birth, it is judged that the child has no defects in the development of the esophagus, stomach, intestine, anal anus. Obstruction of the organs requires immediate surgical intervention.
During the first 10-20 hours of life, the intestinal tract of the child is almost sterile, then begins to colonize it with the bacterial flora necessary for digesting food. Changed and the type of stool - appears kal - the mass of yellow color, consisting of 1/3 of saliva, gastric, intestinal juices and 1/3 of the remainder of food. In this, the work of the digestive glands is also noticeable.
The largest of them, which is also a protective barrier to the body on the path of toxic compounds - the liver - is relatively high in infants. But in healthy, the edge of the liver can protrude from under the lowest rib (at the border of the chest and abdomen) by no more than 2 cm.
Genitourinary system. By the time of birth, the kidneys, ureters, bladder are formed quite well. However, the severe stress experienced by the child during childbirth short-term disturbs metabolism. In areas where urine is formed, the deposition of uric acid crystals occurs and the function of the kidneys is somewhat reduced for the first few days. The child urinates only 5-6 times a day. From the 2nd week the metabolism gradually stabilizes, the number of urination increases to 20-25 times in knocking. This frequency is normal for the first months, given the relatively small volume and insufficient dilatability of the walls of the bladder. The external genitalia are formed. In boys, the testicles are most often lowered into the scrotum, but if they are in the lower part of the abdomen, they can descend independently in the first 3 years.
In girls, large labia cover small.
Metabolism. The need for carbohydrates has been increased, the absorption of fats and their deposition in tissues have been intensified. The water-salt balance is easily disturbed: the daily requirement for a liquid is 150-165 ml / kg.
Hooding. In newborns, the main focus of hematopoiesis is the red bone marrow of all bones, additional - the liver, spleen, lymph nodes. The spleen is about the size of the palm of the child, the lower edge of it is in the projection of the left costal arch (the lowest protruding rib on the border of the chest and abdomen). Lymph nodes, as a rule, can not be detected during examination, their protective function is reduced.
Endocrine system. The adrenal glands carry the greatest load of all the glands and part of their cells die, which determines the course of certain border states (see Section Transitional States). The thymus, which plays a protective role, is relatively large at birth, and subsequently decreases in size. The thyroid and parathyroid glands, the pituitary gland, continue to develop after birth. Pancreas, involved in digestion and taking part in the metabolism of carbohydrates (produces hormone insulin) at the time of birth functions well.
Nervous system. Immature. The convolutions of the brain are barely indicated. Stronger developed in those departments where there are vital centers responsible for breathing, heart work, digestion, etc. In infancy sleep most of the day, waking up only from hunger and unpleasant sensations. Congenital reflexes, such as sucking, swallowing, grasping, blinking, etc., are well expressed, and by the 7th-10th day of life, the so-called. Conditioned reflexes, a reaction to the taste of food, a certain posture, usually associated with feeding, to his hour the child soon begins to wake up himself.
Sense organs. In the first weeks, the sense of smell almost do not smell, only extremely loud sound can awaken, only a very bright light disturbs. The child's unintelligible look does not linger on anything, many have physiological strabismus due to weakness of the eye muscles, involuntary movements of the eyeballs - nystagmus. Up to 2 months he cries without tears - tear glands do not produce a liquid. He is helped to learn the world while only taste sensations, touch and temperature sensitivity. But about the two-month period, you can not say that he is "blind and deaf." True sign - stubbornly looks at the ringing bright rattle.
Immunity. Some factors that play a protective role in the body are produced in utero. Some of the immune substances the child receives from a mother with colostrum, in which their concentration is very high, and with breast milk, where their content is much lower, but in sufficient quantity. But in general, the immune system is imperfect, the child is wounded in terms of infection.
Physical and psychomotor development. For 4 weeks the child adds 600,800 g in weight, 3-4 cm in growth. Already for 4-5 hours a day he is awake, making attempts to smile, raise his head, lying on his stomach.
Classes: communicating, affectionately talking with him, singing, at first straightened up, and then leaning towards his face. Walk around the bed, which teaches children to focus and watch the sound.
Before each feeding and sleeping lay on the stomach.
Recommended toys: large, bright, but not multicolored, which tire. Attractive simple form, rattle. Suspend at a distance of 70 cm from the chest, slowly move from side to side and ring them.