Bitterness in the mouth after. How to get rid of bitterness in the mouth

During childhood there is an intensive maturation of the child's body, in particular the maturation of his nervous system and brain. During the first seven years of life, the mass of the brain increases by about 3.5 times, its structure changes, and functions improve. Brain maturation is very important for mental development: thanks to it, the possibilities of assimilation increase various activities, the child's working capacity increases, conditions are created that allow for more systematic and purposeful training and education.

The course of maturation depends on whether the child receives enough external impressions, do adults create the conditions of education necessary for active work brain. Science has proven that areas of the brain that are not exercised cease to mature normally and may even atrophy (lose the ability to function). This is especially evident in early stages development.

The maturing organism is the most fertile ground for education. We know what impression the events that take place in childhood make on us, what influence they sometimes have on the whole later life. Training, about

taught in childhood is more important for the development of mental qualities than adult education.

Natural prerequisites - the structure of the body, its functions, its maturation - the basis for mental development; without these prerequisites, development cannot take place, but the genotype does not fully determine what kind of mental qualities appear in a person. Development depends on the genotype, living conditions and upbringing, as well as on the internal position of the person himself.

Social experience is the source of mental development, from which the child, through an intermediary (adult), receives material for the formation of mental qualities and personality traits. An adult person himself uses social experience for the purpose of self-improvement.

Age (biological and social). Age stages of mental development are not identical biological development. They are of historical origin. Of course, childhood, understood in the sense physical development man, the time required for his growth, is a natural, a natural phenomenon. But the duration of the period of childhood, when the child does not participate in social labor, but only prepares for such participation, and the forms that this preparation takes, depend on socio-historical conditions.

Data on how childhood passes among peoples at different stages of social development show that the lower this stage, the earlier the growing person is included in adult types of labor. In a primitive culture, children literally from the moment they start walking work together with adults. Childhood as we know it appeared only when the work of adults became inaccessible to the child, began to demand great pre-training. It was singled out by mankind as a period of preparation for life, for adult activities during which the child must acquire necessary knowledge, skills, mental qualities and personality traits. And every age stage called upon to play a special role in this preparation.

The role of the school is to give the child the knowledge and skills necessary to different types specific human activity(work on different areas social production, science, culture), and develop the appropriate mental qualities. The significance of the period from birth to entry into school lies in the preparation of more general, initial human knowledge and skills, mental qualities and personality traits that every person needs for life in society. These include mastery of speech, the use of household items, the development of orientation in space and time, the development human forms perception, thinking, imagination, etc., for

laying the foundations of relationships with other people, initial familiarization with works of literature and art.

In accordance with these tasks, on the one hand, and the capabilities of each age group- on the other hand, society gives children a certain place among people, develops a system of requirements for them, a range of their rights and obligations.

Naturally, as children's abilities grow, these rights and obligations become more serious, in particular, the degree of independence assigned to the child and the degree of responsibility for his actions increase.

Adults organize the lives of children, build upbringing in accordance with the place assigned to the child by society. Society determines the adults' ideas about what can be required and expected from a child at each age stage.

The attitude of the child to the world around him, the range of his duties and interests, in turn, depend on the place he occupies among other people, the system of requirements, expectations and influences on the part of adults. If a baby is characterized by a need for constant emotional communication with an adult, then this means that the whole life of the baby is entirely determined by the adult, and is determined not by any indirect, but by the most direct and immediate way: in this case, an almost continuous physical contact when an adult swaddles a child, feeds him, gives him a toy, supports him during his first attempts to walk, etc.

Arising in early childhood the need for cooperation with an adult, interest in the immediate subject environment are related to the fact that, given the growing capabilities of the child, adults change the nature of communication with him, move on to communication about certain objects and actions. They begin to demand from the child a certain independence in servicing himself, which is impossible without mastering the methods of using objects.

The emerging needs to join the actions and relationships of adults, the exit of interests beyond the immediate environment and, at the same time, their focus on the process of activity itself (and not on its result) - all this distinguishes a preschooler and finds expression in role-playing game. These features reflect the duality of the place occupied by children preschool age among other people. On the one hand, the child is expected to understand human actions, distinguish between good and evil, and consciously comply with the rules of behavior. On the other hand, all the vital needs of the child are satisfied by adults, the child does not bear serious obligations, adults do not make any significant demands on the results of his actions.

Going to school is a turning point in a child's life. The sphere of application of mental activity is changing - the game is replaced by teaching. From the first day at school, new requirements are imposed on the student, corresponding to learning activities. According to these requirements, yesterday's preschooler must be organized, succeeding in the assimilation of knowledge; he must learn the rights and duties corresponding to the new position in society.

A distinctive feature of the position of the student is that his study is a mandatory, socially significant activity. For her, the student must be responsible to the teacher, family, himself. The life of a student is subject to a system of rules that are the same for all students. The main rule is the acquisition of knowledge that he must learn for the future, for the future.

Modern living conditions (in an environment of socio-economic crisis) have created new problems: 1) economic, which at the level of schoolchildren act as the problem "Children and money"; 2) ideological - the choice of position in relation to religion; at the level of children and adolescence it is the problem of "Children and Religion"; 3) moral - the instability of legal and moral criteria, which at the level of adolescence and youth act as problems "Children and AIDS", " Early pregnancy" etc.

Social conditions also determine value orientations, occupation and emotional well-being of adults.

Pregnancy- this is physiological process in which a new organism develops in the uterus, resulting from fertilization. Pregnancy lasts an average of 40 weeks (10 obstetric months).

In the intrauterine development of a child, two periods are distinguished:

Embryonic(up to 8 weeks of pregnancy inclusive). At this time, the embryo is called an embryo and acquires the features characteristic of a person;
Fetal(from 9 weeks to birth). At this time, the embryo is called a fetus.

The growth of the child, the formation of his organs and systems goes naturally in different periods prenatal development, which is subject to the genetic code embedded in the germ cells and fixed in the process of human evolution.

Embryo development in the first obstetric month (1-4 weeks)

First week (1-7 days)

Pregnancy starts from the moment fertilization- mature fusion male cell(sperm) and female egg. This process usually occurs in the ampulla of the fallopian tube. After a few hours, the fertilized egg begins to divide exponentially and descends fallopian tube into the uterine cavity (this path takes up to five days).

As a result of division it turns out multicellular organism , which looks like a blackberry (in Latin "morus"), which is why the embryo at this stage is called morula. Approximately on the 7th day, the morula is introduced into the wall of the uterus (implantation). Villi outer cells the embryo connects with the blood vessels of the uterus, subsequently the placenta is formed from them. Other outer cells of the morula give rise to the development of the umbilical cord and membranes. From internal cells after some time, various tissues and organs of the fetus will develop.

Information At the time of implantation, a woman may have small bloody issues from the genital tract. Such secretions are physiological and do not require treatment.

Second week (8-14 days)

The outer cells of the morula grow tightly into the lining of the uterus. At the fetus the formation of the umbilical cord, placenta, as well as neural tube, from which it subsequently develops nervous system fetus.

Third week (15-21 days)

The third week of pregnancy is a difficult and important period.. At that time important organs and systems begin to form fetus: the rudiments of the respiratory, digestive, circulatory, nervous and excretory systems. In the place where the fetal head will soon appear, a wide plate is formed, which will give rise to the brain. On day 21, the baby's heart begins to beat.

Fourth week (22-28 days)

This week fetal organ laying continues. The rudiments of the intestines, liver, kidneys and lungs are already present. The heart begins to work more intensively and pumps more and more blood through the circulatory system.

From the beginning of the fourth week in the embryo body wrinkles appear, and appears rudiment of the spine(chord).

Ends by day 25 neural tube formation.

By the end of the week (approximately 27-28 days) formed muscular system, spine, which divides the embryo into two symmetrical halves, and upper and lower limbs.

During this period begins formation of pits on the head, which will later become the eyes of the fetus.

Development of the embryo in the second obstetric month (5-8 weeks)

Fifth week (29-35 days)

During this period, the embryo weighs about 0.4 grams, length 1.5-2.5 mm.

Formation begins the following bodies and systems:

Digestive system: liver and pancreas;
Respiratory system: larynx, trachea, lungs;
Circulatory system;
reproductive system: precursors of germ cells are formed;
sense organs: eye and inner ear formation continues;
Nervous system: the formation of brain regions begins.

At that time a faint umbilical cord appears. The formation of limbs continues, the first rudiments of nails appear.

On the face formed upper lip and nasal cavities.

Sixth week (36-42 days)

Length embryo during this period is about 4-5mm.

Starts in the sixth week placenta formation. At this time, it is just beginning to function, the blood circulation between it and the embryo has not yet been formed.

Continues formation brain and its departments. At the sixth week, when performing an encephalogram, it is already possible to fix signals from the fetal brain.

Begins facial muscle formation. The eyes of the fetus are already more pronounced and uncovered by the eyelids, which are just beginning to form.

During this period, they begin upper limbs change: they lengthen and the rudiments of hands and fingers appear. The lower limbs are still in their infancy.

Changes are coming important organs :

Heart. The division into chambers is completed: ventricles and atria;
urinary system. Formed primary kidneys, the development of the ureters begins;
Digestive system. The formation of departments begins gastrointestinal tract: stomach, small and large intestines. By this period, the liver and pancreas had practically completed their development;

Seventh week (43-49 days)

The seventh week is significant in that the final the formation of the umbilical cord is completed and uteroplacental circulation is established. Now the breathing and nutrition of the fetus will be carried out due to the circulation of blood through the vessels of the umbilical cord and placenta.

The embryo is still bent in an arcuate manner; there is a small tail on the pelvic part of the body. The size of the head is at least the entire half of the embryo. The length from the crown to the sacrum grows by the end of the week up to 13-15 mm.

Continues development upper limbs . The fingers are clearly visible, but their separation from each other has not yet occurred. The child begins to perform spontaneous hand movements in response to stimuli.

Good eyes formed, already covered with eyelids that protect them from drying out. The child can open his mouth.

There is a laying of the nasal fold and nose, two paired elevations are formed on the sides of the head, from which they will begin to develop ear shells.

Intensive development of the brain and its parts.

Eighth week (50-56 days)

The body of the embryo begins to straighten, length from the crown of the head to the coccyx is 15 mm at the beginning of the week and 20-21 mm on day 56.

Continues formation of important organs and systems: digestive system, heart, lungs, brain, urinary system, reproductive system(boys develop testicles). The organs of hearing are developing.

By the end of the eighth week the face of the child becomes familiar to a person: well-defined eyes, covered with eyelids, nose, auricles, lip formation ends.

Intensive growth of the head, upper and lower horses is noted. features, ossification develops long bones arms and legs and skull. Fingers are clearly visible, there is no skin membrane between them.

Additionally 8th week ends embryonic period development and fetal begins. The embryo from this time is called the fetus.

Fetal development in the third obstetric month (9-12 weeks)

Ninth week (57-63 days)

At the beginning of the ninth week coccygeal-parietal size fetus is about 22 mm, by the end of the week - 31 mm.

going on improvement of the vessels of the placenta which improves uteroplacental blood flow.

Development of the musculoskeletal system continues. The process of ossification begins, the joints of the toes and hands are formed. The fruit begins to make active movements, can pinch fingers. The head is lowered, the chin is closely pressed to the chest.

Changes occur in the cardiovascular system. The heart makes up to 150 beats per minute and pumps blood through its blood vessels. The composition of blood is still very different from the blood of an adult: it consists only of red blood cells.

Continues further growth and development of the brain, structures of the cerebellum are formed.

Organs develop rapidly endocrine system in particular, the adrenal glands, which produce important hormones.

Improved cartilage tissue : auricles, cartilages of the larynx, vocal cords are being formed.

Tenth week (64-70 days)

By the end of the tenth week fruit length from coccyx to crown is 35-40 mm.

Buttocks begin to develop, the previously existing tail disappears. The fetus is in the uterus in a fairly free position in a half-bent state.

The development of the nervous system continues. Now the fetus performs not only chaotic movements, but also reflex ones in response to a stimulus. When accidentally touching the walls of the uterus, the child makes movements in response: he turns his head, bends or unbends his arms and legs, pushes himself to the side. The size of the fetus is still very small, and the woman cannot yet feel these movements.

The sucking reflex develops, the child begins reflex movements of the lips.

Diaphragm development completes, which will take Active participation in breath.

Eleventh week (71-77 days)

By the end of this week coccygeal-parietal size fetus increases to 4-5 cm.

The body of the fetus remains disproportionate: small body big sizes heads, long arms and short legs, bent at all joints and pressed to the stomach.

The placenta has already reached sufficient development and copes with its functions: provides oxygen to the fetus and nutrients and outputs carbon dioxide and exchange products.

going on further formation fetal eye: at this time, the iris develops, which will later determine the color of the eyes. The eyes are well developed, semi-lidded or wide open.

Twelfth week (78-84 days)

Coccygeal-parietal size fetus is 50-60 mm.

Goes distinctly the development of the genital organs according to the female or male type.

going on further improvement digestive system. The intestines are elongated and fit in loops, as in an adult. Its periodic contractions begin - peristalsis. The fetus begins to make swallowing movements, swallowing amniotic fluid.

The development and improvement of the fetal nervous system continues. The brain is small, but exactly repeats all the structures of the brain of an adult. The cerebral hemispheres and other departments are well developed. Reflex movements are improved: the fetus can squeeze and unclench its fingers into a fist, captures thumb and actively sucks it.

In the blood of the fetus not only erythrocytes are already present, but the production of white blood cells- leukocytes.

At this time the child single respiratory movements begin to register. Before birth, the fetus cannot breathe, its lungs do not function, but it makes rhythmic movements of the chest, imitating breathing.

By the end of the week, the fetus eyebrows and eyelashes appear, the neck is clearly visible.

Fetal development in the fourth obstetric month (13-16 weeks)

13 weeks (85-91 days)

Coccygeal-parietal size by the end of the week is 70-75 mm. The proportions of the body begin to change: the upper and lower limbs and torso lengthen, the size of the head is no longer so large in relation to the body.

Improvement of the digestive and nervous systems continues. Germs of milk teeth begin to appear under the upper and lower jaws.

The face is fully formed, clearly visible auricles, nose and eyes (completely closed for centuries).

14 weeks (92-98 days)

Coccygeal-parietal size by the end of the fourteenth week increases up to 8-9 cm. The proportions of the body continue to change to more familiar ones. The forehead, nose, cheeks and chin are well defined on the face. The first hair appears on the head (very thin and colorless). The surface of the body is covered with fluffy hairs, which retain the lubrication of the skin and thus perform protective functions.

Improved musculoskeletal system fetus. Bones become stronger. intensifies physical activity: the fetus can roll over, bend, make swimming movements.

Completed kidney development Bladder and ureters. The kidneys begin to excrete urine, which mixes with the amniotic fluid.

: pancreatic cells begin to work, producing insulin, and pituitary cells.

There are changes in the genitals. Boys develop prostate, in girls, the ovaries migrate into the pelvic cavity. At the fourteenth week, with a good sensitive ultrasound machine, it is already possible to determine the sex of the child.

Fifteenth week (99-105 days)

Coccygeal-parietal size of the fetus is about 10 cm, fruit weight - 70-75 grams. The head still remains quite large, but the growth of the arms, legs and torso begins to outpace it.

Improved circulatory system . In a child in the fourth month, it is already possible to determine the blood type and Rh factor. Blood vessels (veins, arteries, capillaries) grow in length, their walls become stronger.

The production of original feces (meconium) begins. This is due to the ingestion of amniotic fluid, which enters the stomach, then into the intestines and fills it.

Fully formed fingers and toes, they have an individual pattern.

Sixteenth week (106-112 days)

The weight of the fetus increases to 100 grams, the coccygeal-parietal size - up to 12 cm.

By the end of the sixteenth week, the fetus is already fully formed., he has all the organs and systems. The kidneys are actively working, every hour no a large number of urine.

Fetal skin is very thin, subcutaneous adipose tissue practically absent, so blood vessels shine through the skin. The skin looks bright red, covered with downy hairs and grease. Eyebrows and eyelashes are well defined. Nails are formed, but they cover only the edge of the nail phalanx.

Mimic muscles are formed, and the fetus begins to "grimace": a frown of eyebrows is observed, a semblance of a smile.

Fetal development in the fifth obstetric month (17-20 weeks)

Seventeenth week (113-119 days)

The weight of the fetus is 120-150 grams, the coccygeal-parietal size is 14-15 cm.

The skin remains very thin, but under it, subcutaneous fatty tissue begins to develop. The development of milk teeth, which are covered with dentin, continues. Under them, the germs of permanent teeth begin to form.

Reaction to sound stimuli. From this week, you can say for sure that the child began to hear. When strong sharp sounds appear, the fetus begins to move actively.

Fetal position changes. The head is raised and is almost in vertical position. Hands bent in elbow joints, fingers almost all the time clenched into a fist. Periodically, the child begins to suck his thumb.

Becomes distinct heartbeat. From now on, the doctor can listen to him with a stethoscope.

Eighteenth week (120-126 days)

The weight of the child is about 200 grams, length - up to 20 cm.

The formation of sleep and wakefulness begins. Most of the time the fetus sleeps, movements stop for this time.

At this time, a woman may already begin to feel the movement of the child, especially when repeated pregnancies. The first movements are felt as gentle jolts. A woman can feel more active movements during excitement, stress, which is reflected in emotional state child. At this time, the norm is about ten episodes of fetal movement per day.

Nineteenth week (127-133 days)

The weight of the child increases to 250-300 grams, body length - up to 22-23 cm. The proportions of the body change: the head lags behind the body in growth, arms and legs begin to lengthen.

Movements become more frequent and noticeable. They can be felt not only by the woman herself, but also by other people, putting their hand to their stomach. Primigravida at this time can only begin to feel movements.

Improves the endocrine system: the pancreas, pituitary, adrenals, gonads, thyroid and parathyroid glands are actively functioning.

The composition of the blood has changed: in addition to erythrocytes and leukocytes, there are monocytes and lymphocytes in the blood. The spleen begins to take part in hematopoiesis.

Twentieth week (134-140 days)

Body length increases to 23-25 cm, weight - up to 340 grams.

Fetal skin is still thin, covered with a protective lubricant and fluffy hairs that can persist until the very birth. Intensively develops subcutaneous adipose tissue.

Well formed eyes, at twenty weeks the blink reflex begins to appear.

Improved movement coordination: the child confidently brings his finger to his mouth and begins to suck it. Expressed facial expressions: the fetus can close his eyes, smile, frown.

This week, all women feel the movements regardless of the number of pregnancies. Movement activity changes throughout the day. When irritants appear loud sounds, stuffy room) the child begins to move very violently and actively.

Fetal development in the sixth obstetric month (21-24 weeks)

Twenty-first week (141-147 days)

Body weight grows up to 380 grams, fetal length - up to 27 cm.

Layer subcutaneous tissue increases. The skin of the fetus is wrinkled, with many folds.

Fetal movements become more and more active and tangible. The fetus moves freely in the uterine cavity: lies down with its head or buttocks, across the uterus. It can pull the umbilical cord, push off with hands and feet from the walls of the uterus.

Changes in sleep and wake patterns. Now the fetus spends less time sleeping (16-20 hours).

Twenty-second week (148-154 days)

At week 22, the size of the fetus increases to 28 cm, weight - up to 450-500 grams. The size of the head becomes proportional to the trunk and limbs. The legs are almost all the time in a bent state.

Fully formed fetal spine: it has all the vertebrae, ligaments and joints. The process of strengthening bones continues.

Improvement of the fetal nervous system: the brain already contains all the nerve cells (neurons) and has a mass of about 100 grams. The child begins to take an interest in his body: he feels his face, arms, legs, tilts his head, brings his fingers to his mouth.

Significantly enlarged heart, are being improved functionality of cardio-vascular system.

Twenty-third week (155-161 days)

The body length of the fetus is 28-30 cm, weight - about 500 grams. The pigment begins to be synthesized in the skin, as a result, the skin acquires a bright red color. The subcutaneous fatty tissue is still quite thin, as a result, the child looks very thin and wrinkled. Lubrication covers the entire skin, is more abundant in the folds of the body (elbow, axillary, inguinal, and other folds).

The development of the internal genital organs continues: in boys - the scrotum, in girls - the ovaries.

Increasing frequency respiratory movements up to 50-60 times per minute.

Still well developed swallowing reflex : the child constantly swallows amniotic fluid with particles of a protective lubricant of the skin. The liquid part of the amniotic fluid is absorbed into the blood, a thick green-black substance (meconium) remains in the intestines. Normally, the intestines should not be emptied until the baby is born. Sometimes swallowing water causes hiccups in the fetus, a woman can feel it in the form of rhythmic movements for several minutes.

Twenty-fourth week (162-168 days)

By the end of this week, the weight of the fetus increases to 600 grams, body length - up to 30-32 cm.

The movements are getting stronger and clearer. The fetus occupies almost the entire place in the uterus, but can still change position and roll over. Muscles grow strongly.

By the end of the sixth month, the child has well-developed sense organs. Vision begins to function. If a bright light falls on the woman's stomach, the fetus begins to turn away, tightly closes the eyelids. Hearing is well developed. The fetus determines for itself pleasant and unpleasant sounds and reacts to them in different ways. With pleasant sounds, the child behaves calmly, his movements become calm and measured. With unpleasant sounds, it begins to freeze or, conversely, moves very actively.

Between mother and child is established emotional connection . If a woman experiences negative emotions(fear, anxiety, longing), the child begins to experience similar feelings.

Fetal development in the seventh obstetric month (25-28 weeks)

Twenty-fifth week (169-175 days)

The length of the fetus is 30-34 cm, body weight increases to 650-700 grams. The skin becomes elastic, the number and severity of folds decreases due to the accumulation of subcutaneous fatty tissue. Skin stays thin large quantity capillaries, giving it a red color.

The face has a familiar human appearance: eyes, eyelids, eyebrows, eyelashes, cheeks, auricles are well expressed. The cartilages of the ears are still thin and soft, their curves and curls are not fully formed.

Intensively developing Bone marrow , which takes on a major role in hematopoiesis. The strengthening of the bones of the fetus continues.

happening important processes in lung maturation: small elements are formed lung tissue(alveoli). Before the birth of the child, they are without air and resemble deflated balloons, which straighten out only after the first cry of the newborn. From the 25th week, the alveoli begin to produce a special substance (surfactant) necessary to maintain their shape.

Twenty-sixth week (176-182 days)

The length of the fetus is about 35 cm, the weight increases to 750-760 grams. Growth continues muscle tissue and subcutaneous adipose tissue. Bones are strengthened and permanent teeth continue to develop.

The formation of genital organs continues. In boys, the testicles begin to descend into the scrotum (the process lasts 3-4 weeks). In girls, the formation of the external genitalia and vagina is completed.

Improved sense organs. The child develops a sense of smell (smell).

Twenty-seventh week (183-189 days)

Weight increases to 850 grams, body length - up to 37 cm.

Organs of the endocrine system are actively functioning in particular the pancreas, pituitary gland and thyroid gland.

The fetus is quite active, makes various movements freely inside the uterus.

From the twenty-seventh week of the child individual metabolism begins to form.

Twenty-eighth week (190-196 days)

The weight of the child increases to 950 grams, body length - 38 cm.

By this age the fetus becomes practically viable. In the absence of organ pathology, the child with good care and treatment can survive.

Subcutaneous adipose tissue continues to accumulate. The skin is still red vellus hair begin to fall out gradually, remaining only on the back and shoulders. Eyebrows, eyelashes, hair on the head become darker. The child begins to open his eyes frequently. The cartilages of the nose and ears remain soft. The nails do not yet reach the edge of the nail phalanx.

This week starts over active functioning of one of the hemispheres of the brain. If it becomes active right hemisphere, then the child becomes left-handed, if left-handed, then right-handedness develops.

Fetal development in the eighth month (29-32 weeks)

Twenty-ninth week (197-203 days)

The weight of the fetus is about 1200 grams, growth increases to 39 cm.

The child has already grown enough and takes up almost all the space in the uterus. The movements are not so chaotic. The movements are manifested in the form of periodic pushes with the legs and arms. The fetus begins to take a definite position in the uterus: head or buttocks down.

All organ systems continue to improve. The kidneys excrete up to 500 ml of urine per day. The load on the cardiovascular system increases. The circulation of the fetus is still significantly different from the circulation of the newborn.

Thirtieth week (204-210 days)

Body weight increases to 1300-1350 grams, growth remains about the same - about 38-39 cm.

Constant accumulation of subcutaneous adipose tissue, crack down skin folds. The child adapts to the lack of space and assumes a certain position: curled up, arms and legs crossed. The skin still has a bright color, the amount of lubrication and vellus hair is reduced.

Continues development of alveoli and production of surfactant. The lungs prepare for the birth of the baby and the start of breathing.

The development of the brain continues brain, the number of convolutions and the area of the cortex increase.

Thirty-first week (211-217 days)

The weight of the child is about 1500-1700 grams, growth increases to 40 cm.

The child's sleep and wake patterns change. Sleep still takes a long time, during this time there is no motor activity of the fetus. During wakefulness, the child actively moves and pushes.

Fully formed eyes. During sleep, the child closes his eyes, during wakefulness, the eyes are open, periodically the child blinks. The color of the iris in all children is the same ( blue color), then after birth begins to change. The fetus reacts to bright light by constriction or dilation of the pupil.

Increases the size of the brain. Now its volume is about 25% of the volume of the brain of an adult.

Thirty-second week (218-224 days)

The height of the child is about 42 cm, weight - 1700-1800 grams.

Continued accumulation of subcutaneous fat, in connection with which, the skin becomes lighter, there are practically no folds on it.

are being improved internal organs : organs of the endocrine system intensively secrete hormones, surfactant accumulates in the lungs.

The fetus produces a special hormone, which promotes the formation of estrogen in the mother's body, as a result, the mammary glands begin to prepare for the production of milk.

Fetal development in the ninth month (33-36 weeks)

Thirty-third week (225-231 days)

The weight of the fetus increases to 1900-2000 grams, growth is about 43-44 cm.

Skin becomes brighter and smoother, the layer of adipose tissue increases. Vellus hair is more and more wiped, the layer of protective lubricant, on the contrary, increases. The nails grow to the edge of the nail phalanx.

The child becomes more and more crowded in the uterine cavity, so his movements become more rare, but strong. The position of the fetus is fixed (head or buttocks down), the likelihood that the child will roll over after this period is extremely small.

The work of internal organs is improving: the mass of the heart increases, the formation of alveoli is almost completed, the tone increases blood vessels fully formed brain.

Thirty-fourth week (232-238 days)

The weight of the child ranges from 2000 to 2500 grams, height is about 44-45 cm.

The baby is now in a stable position in the uterus. The bones of the skull are soft and mobile thanks to the fontanelles, which can close only a few months after childbirth.

The hair on the head grows intensively and take on a certain color. However, hair color may change after childbirth.

Significant strengthening of bones, in connection with this, the fetus begins to take calcium from the mother's body (a woman at this time may notice the appearance of seizures).

Baby swallows amniotic fluid all the time, thereby stimulating the gastrointestinal tract and the functioning of the kidneys, which secrete at least 600 ml of clear urine per day.

Thirty-fifth week (239-245 days)

Every day the child adds 25-35 grams. Weight in this period can vary greatly and by the end of the week is 2200-2700 grams. Height increases to 46 cm.

All the internal organs of the child continue to improve, preparing the body for the upcoming extrauterine existence.

Fatty tissue is intensively deposited, the child becomes more well-fed. The amount of vellus hair is greatly reduced. The nails have already reached the tips of the nail phalanges.

A sufficient amount of meconium has already accumulated in the intestines of the fetus, which normally should depart 6-7 hours after childbirth.

Thirty-sixth week (246-252 days)

The weight of the child varies greatly and can range from 2000 to 3000 grams, height - within 46-48 cm

The fetus already has well-developed subcutaneous adipose tissue, skin color becomes light, wrinkles and folds completely disappear.

The baby takes a certain position in the uterus: more often he lies upside down (less often, legs or buttocks, in some cases, transversely), the head is bent, the chin is pressed to the chest, arms and legs are pressed to the body.

Skull bones, unlike other bones, remain soft, with cracks (fontanelles), which will allow the baby's head to be more pliable when passing through the birth canal.

All organs and systems are fully developed for the existence of a child outside the womb.

Fetal development in the tenth obstetric month

Thirty-seventh week (254-259 days)

The height of the child increases to 48-49 cm, the weight can fluctuate significantly. The skin has become lighter and thicker, the fat layer increases by 14-15 grams per day every day.

cartilage of the nose and auricles become tighter and more elastic.

Fully formed and mature lungs, the alveoli contain required amount surfactant for neonatal breathing.

Completion of the digestive system: In the stomach and intestines, there are contractions necessary to push food through (peristalsis).

Thirty-eighth week (260-266 days)

The weight and height of the child varies greatly.

The fetus is fully mature and ready to be born. Outwardly, the child looks like a full-term newborn. The skin is light, fatty tissue is sufficiently developed, vellus hair is practically absent.

Thirty-ninth week (267-273 days)

Usually two weeks before delivery fetus starts to drop clinging to the bones of the pelvis. The child has already reached full maturity. The placenta begins to gradually grow old and metabolic processes worsen in it.

The mass of the fetus increases significantly (30-35 grams per day). Body proportions change completely: well developed rib cage and shoulder girdle, rounded belly, long limbs.

Well developed sense organs: the child catches all sounds, sees bright colors, can focus vision, taste buds are developed.

Fortieth week (274-280 days)

All indicators of fetal development correspond to the neonatal born. The child is completely ready for childbirth. Weight can vary significantly: from 250 to 4000 and above grams.

The uterus begins to contract periodically(), which is manifested aching pains lower abdomen. The cervix opens slightly, and the fetal head is pressed closer to the pelvic cavity.

The bones of the skull are still soft and pliable, which allows the baby's head to change shape and easier to pass through the birth canal.

Fetal development by week of pregnancy - Video

Even during the stay baby in his mother's tummy he is forming nervous system, which will then control reflexes baby. Today we will talk in more detail about the features of the formation of the nervous system and what parents need to know about it.

In the womb fetus receives everything he needs, he is protected from dangers and diseases. During the formation of the embryo brain produces about 25 thousand nerve cells. For this reason, future mother must think and take care of health not to be negative consequences for the baby.

By the end of the ninth month, the nervous system reaches almost complete development. But despite this, the adult brain harder than the brain just born baby.

During normal running pregnancy and childbirth, the baby is born with a formed CNS but it is still not mature enough. Tissue develops after birth brain, however, the number of cells of the nervous system in it does not change.

At baby there are all convolutions, but they are not sufficiently expressed.

Fully formed and developed by the time the baby is born is spinal cord.

Influence of the nervous system

After birth child finds himself in the unknown and strange for him world to which you need to adapt. It is this task that the infant's nervous system performs. She is primarily responsible for congenital reflexes, which include grasping, sucking, protective, crawling, and so on.

Within 7-10 days of a child's life, they begin to form conditioned reflexes, which often control the reception food.

As a child grows up, some reflexes disappear. It is through this process doctor judges whether a child has crashes in the functioning of the nervous system.

CNS controls performance bodies and systems throughout the body. But due to the fact that it is not yet completely stable, the baby may experience Problems: colic, unsystematic stools, moodiness and so on. But in the process of its maturation, everything returns to normal.

In addition, the CNS also influences schedule baby. Everyone knows that babies spend most of the day are sleeping. However, there are also deviations requiring a consultation with a neurologist. Let's clarify: in the first days after birth newborn should sleep from five minutes to two hours. Then comes the period of wakefulness, which is 10-30 minutes. Deviations from these indicators may indicate a problem.

It's important to know

You should know that the baby's nervous system is quite flexible and is characterized by exceptional ability to recreate - it happens that dangerous signs, which were identified by doctors after the birth of the baby, in the future just disappear.

For this reason, one medical inspection cannot be used as staging diagnosis. This requires a large number surveys by several doctors.

Do not panic if, upon examination neurologist the baby will have certain deviations in the work of the nervous system - for example, changes in tone muscles or reflexes. As you know, babies are distinguished by a special reserve strength The main thing is to detect the problem in time and find ways to solve it.

Closely monitor the health of the baby from the day conception and timely prevent the impact of negative factors on his health.

The nervous system develops from the outer germ layer - the ectoderm. It is laid at the age of 2.5 weeks in the form of a neural plate, which first turns into a groove, and then into a tube. There are two types of embryonic cells in the wall of the tube: neuroblasts - future neurons and spongioblasts - future glial cells. The spinal cord develops from the posterior end of the tube, and the brain develops from the anterior end, which is characterized by extremely rapid growth rates and late dates maturation.

Development of central and peripheral departments nervous system is heterochronous. The general biological law is reflected in the development of the nervous system: ontogeny repeats phylogenesis. The older departments in evolutionary terms develop faster, later the young ones. However, no part of the brain works in isolation. The functioning of any department is associated with other departments of the central nervous system.

The maturation of the nervous system goes in the following directions:

weight gain nervous tissue;
differentiation of neurons and neurofibrils;
an increase in the number, length and diameter of neuronal processes and their myelination;
development of glial cells;
improvement of connections between neurons (increase in the number of synapses);
development of spiny apparatus on dendrites;
increase in excitability, conductivity and lability of neurons and fibers;
increase in the synthesis and content of neurotransmitters;
increase in membrane potential.

No indicator is decisive in providing nervous activity, their ratio at each stage of ontogenesis is important.

Development of neurons. At the 3rd month of intrauterine development, axon growth begins, neurofibrils appear, synapses form, and excitation conduction is detected. Dendrites are formed later than axons, towards the end prenatal period, and after birth, the number of their branching and synapses increases. In the human fetus, the cell mass of the CNS reaches its top level in the first 20-24 weeks of intrauterine development, and this number of neurons remains almost constant until old age. Neurons after differentiation generally do not undergo further division, and glial cells continue to divide throughout life. However, the volume of neurons in the early stages of ontogeny increases. AT old age number of cortical neurons hemispheres and the mass of the brain decreases, but the activity of the remaining neurons increases. In the process of development, the ratio between glial and nerve cells changes significantly. In a newborn, the number of neurons is greater than that of glial cells, by the age of 20-30 their ratio becomes equal, after 30 years the number of glial cells increases.

Myelination of the processes of nerve cells begins in utero under the influence of hormones. thyroid gland. At the beginning, the myelin sheath is loose, and then becomes denser. First covered with myelin peripheral nerves, then the processes of nerve cells located in the spinal cord and brain. fibers motor neurons myelinated before the sensitive ones. Myelination in all peripheral nerve fibers is almost completed by the age of 9-10 years. The formation of shells in to a large extent depends on the conditions of the child. Under unfavorable conditions, the process of myelination can slow down for several years, which makes it difficult to control and regulate the activity of the nervous system.

In children early age fewer neurotransmitters are released in the synapses, and they are quickly consumed. Therefore, their performance is low, fatigue quickly sets in. In addition, their action potential is longer, which affects the speed of excitation and lability. nerve fibers. By the age of 9-10, lability reaches almost the level of adults (300-1000 impulses per 1 s). In the same time nerve centers have great compensatory potential. During and some time after birth, brain neurons have low sensitivity to hypoxia. Then the sensitivity to lack of oxygen increases, and in general the child's nervous system is more sensitive to hypoxia due to high level metabolism.

As the body ages, structural and functional changes occur in neurons. So, the total number of neurons decreases to 40-70%, they develop dystrophic processes associated with vacuolization, accumulation of lipids and lipofuscin pigment in the cytoplasm, segmental demyelination of axons develops. The number of synapses, especially axodendritic ones, and the content of neurotransmitters in them decrease. Energy metabolism in cells decreases, which causes a decrease in the formation of ATP, the activity of membrane pumps. This leads to a decrease in the lability of neurons, a slowdown in the rate of conduction of excitation through synapses. In parallel, the structure and functions of glia change. The relative number of glial cells in relation to neurons increases, with a decrease in the function of microglia, the function of astrocytes is activated. Glia begins to supply neurons with plastic materials more actively, removes lipofuscin from them, increases the capture of neuronal mediators, and begins to play a role in the formation and consolidation of temporary connections.