Lesson. Human development after birth

Infancy (1st year of life).The first month of life is considered the neonatal period. The position of the newborn resembles the position of the fetus in the uterus. He sleeps most of the day, waking up only at feeding time. Caring for a newborn requires special cleanliness, maintaining a temperature of at least 20 ° C and strict adherence to feeding times. Failure to comply with the feeding schedule disrupts sleep, makes the child restless, and upsets his digestion. The harmonious development of the child is ensured when he receives mother's milk directly from the breast. Newborn babies digest proteins, fats and carbohydrates best human milk.

From two months of age, vegetable and fruit juices are added to the diet. Feed with easily digestible food. During the first year of life, many changes occur in the child’s motor system. At the end of the 1st month of life, he tries to straighten his legs; at the 6th week, lifts and holds the head; sitting in the 6th month; at the end of the 1st year he tries to take his first steps.

The child’s psyche also develops less intensively during this period. At the 2nd month, the baby smiles when shown bright pictures, when the mother appears; By the 4th month, he takes toys into his mouth, examines them, and begins to distinguish between adults. In the second half of infancy, the child develops the ability to respond with more complex behavior to the presence of the mother, and he begins to understand many of the parents’ phrases.

Infants are especially susceptible to environmental influences. It should be remembered that the correct and systematic physical education of a child leaves a mark on his body for life. Active movements promote muscle growth and development, strengthen the skeletal system, better supply the body with nutrients and oxygen, and most importantly, they normalize activity nervous system. At the core physical education Infants should be guided by three rules: gradualism, repetition, systematicity.

An effective remedy hardening is Fresh air. Its effect is to provide the body with oxygen and increase resistance to colds. The most effective means of hardening is water procedures. They enhance metabolism, regulate the functions of the nervous system, stimulate and enhance the protective functions of the blood.

Good physical and mental development of a child is determined by a rational regimen. A child develops a clear routine for life conditioned reflexes related to eating, digesting it, falling asleep on time, etc. The formation of these reflexes allows parents to develop the necessary life skills in their child. Reinforcing these skills makes them lasting. They remain for life and provide the body with high resistance to adverse factors.

Early childhood. At the age of 1 to 3 years, a child grows rapidly, eats the same food as adults, he manifests a desire for independent knowledge of the world, a craving for self-affirmation. At this age, the child begins to walk and masters different ways manipulation with objects. Many new motor skills appear. During the game, the child imitates the actions of adults. During this period, it is important not to suppress the child’s desire for independence, so that he does not develop character traits such as stubbornness and capriciousness.

Preschool period. Children preschool age(from 3 to 7 years) show great interest in the world around them. The child's curiosity is so great that this period is called the stage of questions. When answering questions, it is necessary to adhere to the tactics of truthful, but understandable answers for the child. Incorrect explanations and attempts to brush aside the child’s questions can lead to a loss of interest and trust in others.

During this period, children's brains continue to grow and internal speech is formed. The external manifestation of this is the child’s conversations with himself. A child’s mental and physical development and knowledge of the world around him are largely determined by play. For a child, play is as important as work and sports for an adult. In the game the child learns the first joys of victory, and in it he receives the first moral lessons: compassion, wisdom, honesty, justice. Outdoor games, especially in the fresh air, improve the muscular system. Games promote the development of imagination and imagination, encourage the child to be creative. Preschoolers have rich emotions and fantasies.

School period. At the age of 7 to 17 years, the activity of all organs and systems undergoes a restructuring. Entering school is the most difficult stage in a child's life. If before school the child’s main activity was play, now he is obliged to regulate his life according to the requirements of strict school discipline. Teaching is serious, intense and quite persistent work. In their studies, primary schoolchildren gradually master writing, learn a lot about the world around them, and assimilate the experience accumulated by many generations of people. Schooling six-year-old children accelerates their development of new skills and abilities compared to those same-year-olds who attend kindergartens. At school, the child first feels the influence of collective influence - in studies, social work, labor education, sports. All this contributes to the harmonious mental, physical, and volitional development of schoolchildren.

At the age of 11, a new age period begins. We already call former children teenagers. They undergo a profound restructuring of the activity of all organs and physiological systems. This restructuring is associated with the intensive formation of sex hormones and puberty. In boys aged 13-15 years, the muscles of the back and chest develop, body weight increases, and the thickness of the subcutaneous fat layer decreases. An abdominal type of breathing is formed: in boys, inhalation occurs mainly due to contraction of the abdominal diaphragm muscles. The voice breaks, the mustache and beard, pubic and armpit hair appear. In boys, at night, semen begins to erupt from the urethra - emission. The intervals between emissions are usually 7-14 days.

In girls aged 11-14 years, along with the development of the muscular system, the subcutaneous fat layer gradually increases, and a thoracic type of breathing is formed, i.e., inhalation occurs mainly due to the contraction of the intercostal muscles. In girls, the mammary glands develop and menstruation begins. Outwardly, it manifests itself in periodic bleeding from the uterus (menstruation) that occurs at regular intervals. Essentially, this is a reflection of a complex physiological process, which consists of regularly repeating profound changes in the female body. They are caused by the fact that the egg periodically matures in the female body. If it is not fertilized, menstruation occurs.

At this time, adolescents experience increased excitability, increased irritability, and sleep disorders. Reasonable advice from parents and teachers, tactful attitude of teenagers towards each other, attentive and caring attitude towards girls help ensure that the transition period passes without serious disorders and complications. The increased release of hormones in adolescents, especially from the adrenal cortex, maintains a state of high activity in the adolescent’s body. Sharp fluctuations in blood pressure, discomfort in various parts body, decreased appetite, frequent mood swings. This tension is relieved during exercise. various types sports, participation in amateur clubs, modeling, performing interesting social activities, and involvement in household work.

In adolescence, speech development ends, character formation occurs, as well as the moral formation of personality. This is facilitated by a correct, healthy regimen, a calm environment, goodwill on the part of people around him, interesting activities for a teenager, and cultivating high moral qualities.

IN last decades in all economic developed countries the pace of physical and sexual development of children, called acceleration. Let us present some indicators of height and body weight that characterize the acceleration process over the past 50 years. In the 20s of our century, the height of 14-year-old boys reached an average of 145.4 cm, in the 70s the height reached 162.6 cm, and body weight increased on average by 13.5 kg. The average height and body weight of girls also increased noticeably. The reasons for acceleration are complex, diverse and not fully understood. It has been established that the earlier physical development of modern children does not automatically entail an acceleration of their moral and social maturation.

They distinguish between physiological, psychological and social maturity. Physiological maturity is the stage of puberty in the body. The time it takes to reach physiological maturity varies from person to person. It depends on climatic, hereditary and other factors. It is a mistake to think that from the moment of physiological maturity, boys and girls become adults. Early start sexual activity leads to stunted growth, physical and mental development. The most common manifestation of early sexual intercourse is weakening of sexual functions. Pregnancy resulting from casual sexual intercourse can result in the birth of physically and mentally handicapped children.

Girls cause irreparable harm to their bodies by drinking alcohol and smoking. Female alcoholism poses a serious danger to our descendants. This manifests itself not only in the inability drinking women breastfeeding children, giving birth to children with diseases of internal organs, deformities, mental disorders. It is better for a woman preparing to become a mother to stop drinking alcohol and smoking. She must constantly remember that the alcohol and nicotine that enter her body easily penetrate the circulatory system of the fetus, leading to the formation of a defective fetus. Drinking coffee and strong tea can also be harmful.

Psychological maturity- the stage of development during which boys and girls acquire moral stability and sufficient self-control of behavior in the family and society.

Social maturity- formation of a conscious, full-fledged member of society. It does not coincide in time with physical maturation. A person’s social maturity is determined by a number of conditions: completion of education, beginning labor activity, economic independence, political and civil improvement, military service, etc.

Basic terms and concepts:

Breast period. Early childhood. Preschool period. School period. Acceleration. Physiological maturity. Psychological maturity. Social maturity.

Card on the board:

How long does infancy last?

How long does the newborn period last?

How long does a child's period last? early childhood?

How long does a child's preschool period last?

When does adolescence begin?

What type of breathing is formed in boys? For girls?

What is acceleration?

Letter cards:

Infancy in human life.

Characteristics of the preschool period.

The school period in a person’s life.

Give definitions or expand on the concepts: Breast period. Early childhood Acceleration. Physiological maturity. Psychological maturity. Social maturity.

Computer testing:

Test 1. How long does infancy last?

Test 2. How long does the neonatal period last?

Test 3. How long does a child's early childhood last?

Up to 1 year.

From one year to 3 years.

From 3 years to 7 years.

From one year to 7 years.

Test 4. How long does the child's preschool period last?

Up to 1 year.

From one year to 3 years.

From 3 years to 7 years.

From one year to 7 years.

Test 5. When does adolescence begin:

Test 6. What type of breathing is formed in boys?

Chest type.

Abdominal type.

Test 7. What is acceleration?

Rapid growth of teenagers.

Accelerated puberty in adolescents.

Accelerated physical and sexual development of adolescents.

Accelerated moral and social development of adolescents.

Test 8. What is the physiological maturity of the body?

The age at which the body stops growing.

The age at which an organism reaches puberty.

Test 9

The age when teenagers become adults.

The age when adolescents acquire moral stability and sufficient self-control of behavior in the family and society.

Test 10. What's happened psychological maturity body?

The age when the school period in a teenager’s life ends.

The age when teenagers become adults.

The age when adolescents acquire moral stability and sufficient self-control of behavior in the family and society.

The age that is characterized by the completion of education, the beginning of working life, economic independence, political and civic improvement, military service, etc.

In the individual development of a person, two periods are distinguished: intrauterine and extrauterine. The prenatal period is the time when the formation of organs and body parts characteristic of humans occurs. This period is divided into the embryonic phase (the first 8 weeks), where initial development embryo and organ formation, and the fetal phase (3-9 months), during which further development fetus The extrauterine period is the period when a new individual continues its development outside the mother's body. It lasts from the moment of birth to death.

After birth, a person’s life is divided by age, taking into account morphological and functional characteristics:

1. newborn - from birth to 10 days;

2. infancy - from 10 days to 1 year;

3. early childhood - 1-3 years;

4. first childhood - 4-7 years;

5. second childhood - 8-12 years old - boys, 8-11 years old - girls;

6. adolescence- 13-16 years old - boys, 12-15 years old - girls;

7. adolescence - 17-21 years - boys, 16-20 years - girls;

8. mature age (1st period) - 22-35 years old - men, 21-35 years old women;

9. mature age (2nd period) - 36-60 years - men, 36-55 years - women;

10. old age - 61-74 - men, 56-74 - women;

11. old age - 75-90 years - men and women;

12. long-livers - 90 years or more.

Each age period is characterized by morphofunctional characteristics. Yes, y newborn a child's head is round, large (1/4 of the entire body length, in an adult - 1/8), and its circumference is 34-36 cm. The neck and chest are short, the stomach is long, the legs are short, and the arms are long. The muscles are poorly developed.

Breast period characterized by increased growth and development of organs and systems. Over the course of a year, the child’s body length increases by an average of 25 cm, and the weight reaches 10-11 kg.

IN early childhood period growth slows down: the increase in body weight and length occurs much more slowly than in the first year. During this period, all the child’s organs are somewhat strengthened, their performance increases, muscles and skeleton develop and become stronger.

IN period of first childhood growth in length prevails over increase in body weight. The growth of children in the 4th and 5th year of life slows down somewhat and averages 4-6 cm per year; in the 6th and 7th years of life, the increase in height increases significantly - up to 8-10 cm. This is the first period of elongation, which is associated with functional changes in the endocrine system. By the 5th year, muscles develop significantly, especially in the legs, the muscles become stronger, and their performance increases.

IN period of second childhood growth in width predominates, but at this time puberty begins, and towards the end of the period the growth of the body in length increases, the rate of which is greater in girls. At the age of 10, the first crossover occurs - the length and body weight of girls exceeds that of boys. The muscular system is rapidly developing, but in children of this age the back muscles are still weak and cannot support the body in the correct position for a long time, which can lead to poor posture and curvature of the spine. The function of the gonads begins to increase, which provides corresponding anatomical and physiological differences in the development of boys and girls.

IN adolescence puberty occurs, accompanied by accelerated physical development. Adolescence is divided into adolescence itself (for girls from 12 to 16 years old and for boys from 13 to 17 years old) and adolescence (for girls from 16 years old, for boys from 17 years old).

Physiologically, adolescence is caused by an increase in the production of hormones, the main of which are growth hormone, sex hormones, thyroid hormones, and insulin. Only their simultaneous and complementary action ensures timely and proper development child. Puberty begins with the manifestation of secondary sexual characteristics: pigmentation of the external genitalia, hair growth on the pubis and armpits. Girls reach puberty approximately 2 years earlier than boys, and in the future they also mature faster. This period begins at 10-12 years of age. At 8-10 years of age, rounding of the hips and buttocks and expansion of the pelvis are noted. At 9-10 years of age, the areola protrudes above the skin of the chest. At the age of 10-11 years, single hair appears on the pubis and in the armpits, and further development of the mammary glands is noted. At 11-12 years old you may have your first menstruation. At the age of 15-16, regular menstruation is established, further hair growth is observed on the pubis and in the armpits, and the mammary glands enlarge. Parallel to puberty occurs intensive growth in length, the peak growth rate occurs on average at 12 years and reaches 9 cm per year. At 15-16 years of age, growth gradually stops.

In boys, the timing of the onset and rate of development of puberty varies within very wide limits. Most often, the onset of puberty is observed at 12-14 years of age. At 10-11 years of age, an increase in the size of the testicles and penis is noted. At 11-12 years old - pigmentation of the scrotum, the beginning of pubic hair, further enlargement of the penis and testicles. At 13-14 years old - the beginning of a change in voice, the appearance of hair in the axillary region, on the upper lip, and the development of muscles. At 14-15 years of age - further progression of puberty, first wet dreams. At the age of 18-20, puberty is completed, male-type hair growth occurs. The peak growth rate occurs at 14 years and reaches 10-12 cm per year. At the age of 18-20, there is a gradual cessation of growth.

In both boys and girls, along with an increase in height, body weight increases, on average up to 3-5 kg ​​per year. In adolescents, all body parts, tissues and organs grow and develop rapidly. Growth rates are not the same. Uneven growth of individual parts of the body causes a temporary loss of coordination of movements - clumsiness, clumsiness, and angularity appear. During this period, you need to carefully monitor the teenager’s posture.

Mature age divided into two periods. The first period (for men 22-35 years old, for women 21-35 years old) is marked by a cessation of growth and stability of functional functions that reach optimal development. The shape and structure of the body change little; there is a slight increase in skeletal mass due to the deposition of new layers of bone matter on the surfaces of the bones. The morphofunctional development of the organism is completed. The maximum manifestation of most functions usually occurs at the age of 20-25 years, after which a gradual decrease in the intensity of their manifestation begins. At 20-25 years old, the ideal and proper body weight for this person is observed.

In the second period (for men 36-60 years old, for women 36-55 years old), a gradual neuroendocrine restructuring occurs, the function of the gonads fades away (menopause). Menopause is accompanied by significant changes in physiological functions (the concentration of gonadal hormones in the blood decreases, the functions of the thyroid gland, thymus, and adrenal glands decrease). As we age, these primary changes lead to secondary ones: atrophy of the integument, lethargy, sagging, wrinkling of the skin, graying and hair loss, reduction in muscle volume and tone, and limited mobility in the joints. The first signs of clinical diseases characteristic of older age appear. Body proportions remain constant, but towards the end of this period they begin to decrease.

Elderly and senile age characterized by changes in energy processes in the cell and a decrease in the activity of respiratory enzymes. The regulation of the functions of organs and systems changes significantly. With age, the adaptive capabilities of the heart change significantly. In older and older people, the resting heart rate decreases.

Thus, human growth and development has a number of patterns:

· growth and development depend on a person’s genotype, however, the interaction of a set of genes with each other and with various environmental factors can, to one degree or another, influence the phenotype;

· the growth and development of an individual occurs in stages. At each stage, quantitative and qualitative changes occur in the body, which makes the process irreversible;

Each period of human ontogenesis is manifested by characteristic morphophysiological features.

The process of individual development of any organism is called ontogenesis. The concept of ontogeny was introduced into biology by Ernst Haeckel in 1866. According to modern ideas, ontogenesis (Greek ontos - being, individual, genesis - development) is full cycle individual development of each individual, which is based on the implementation of hereditary information at all stages of existence in certain environmental conditions; it starts with education zygotes(during sexual reproduction) and ends in death. For biological species Homo sapiens characteristically direct intrauterine development.

Depending on the environment in which the human body develops, ontogenesis is divided into two large periods, separated from each other by the moment of birth:

1. Intrauterine(prenatal, or antenatal), when the newly born organism develops in the womb; this period lasts from conception to birth.
2. Extrauterine (postnatal), when a new individual continues its development outside the mother’s body; this period lasts from birth to death.

IN Lately it is also proposed to highlight prezygotic the period preceding the formation of the zygote.

Prezygotic period

Prezygotic period development is associated with the formation of gametes (gametogenesis). The formation of eggs begins in women even before their birth and is completed for each given egg only after its fertilization. By the time of birth, a female fetus in the ovaries contains about two million first-order oocytes (these are still diploid cells), and only 350 - 450 of them will reach the stage of second-order oocytes (haploid cells), turning into eggs (one at a time during one menstrual cycle ). Unlike women, sex cells in the testes (testes) in men begin to form only with the onset of puberty. The duration of sperm formation is approximately 70 days; per gram of testicle weight, the number of sperm is about 100 million per day.

Fertilization is the process of fusion of an egg and a sperm, leading to the formation of a zygote. Fertilization of the egg occurs in the initial section of the fallopian tube, where only about a hundred sperm penetrate. The ability of sperm to fertilize in the female genital tract persists for two days. The sperm has an acrosome in its head, which contains an enzyme to dissolve the membrane of the egg. When the sperm and egg come together, the acrosome ruptures, and the released enzymes dissolve the shell of the female gamete. The sperm penetrates the egg, after which it is covered with a dense membrane that prevents the penetration of other male gametes. As a result of fertilization, the diploid set of chromosomes is restored. The resulting single-celled embryo is a zygote. In it, complex movements of individual sections of the cytoplasm and its organelles occur throughout the day.

Prenatal period Human development lasts 280 days and is divided into:

• initial period(the first week after fertilization, during which the zygote fragments, the formation of a blastula and its implantation into the uterine wall);
• embryonic period(the first two months), when the initial development of the embryo (embryo) occurs and when the main formation of tissues and organs occurs;
• fertile period(3-9 months), when the growth of parts formed in the embryonic stage and the further formation of organs and systems continues. From the third month, the human embryo is called a fetus.

Initial period

Initial period. Splitting up- This is the initial stage of development of a fertilized egg (zygote). In humans, it lasts 3-4 days (the zygote is fragmented through a series of successive mitoses, but without the growth of daughter cells to the size of the zygote). In humans, the fragmentation of the zygote is full and uneven. Cells formed as a result of fragmentation are called blastomeres. The result of the fragmentation stage is the formation of a multicellular embryo - morulas. Crushing and formation of the morula occurs as the embryo moves along the fallopian tube. The morula enters the uterus, where the process takes place blastulation. The blastomeres in the morula repel each other, shift to the periphery and line up in one layer, and by the 6th day a single-layer embryo in the form of a vesicle is formed. Different blastomeres divide at different rates. Some of them (lighter) are located on the periphery, others (darker) are located in the center.

The surrounding embryo is formed from light cells trophoblast, the cells of which play an auxiliary role and do not directly participate in the formation of the embryo body. Trophoblast cells are able to dissolve tissue, due to which the embryo is implanted ( implanted) into the wall of the uterus. Next, the trophoblast cells peel off from the cells of the embryo, forming a vesicle around it. The trophoblast cavity is filled with fluid diffusing into it from the uterine tissue. Formed from dark cells embryoblast, having the appearance of a nodule. As a result of further fragmentation of the embryoblast, the embryo takes the form of a disk, spread out on the inner surface of the trophoblast. This stage of embryonic development, when the trophoblast and embryoblast are distinguished, is called blastocyst. The blastocyst, once in the uterine cavity, implanted, receiving nutrients from the uterine wall. Trophoblast cells differentiate into two layers. From the cells of the outer layer of trophoblast are formed trophoblast villi, which grow into the epithelium of the uterus. This layer with villi forms the outermost membrane of the embryo - chorion. The chorion plays an important role in the nutrition of the developing embryo and the removal of its final metabolic products. At later stages this function is performed by placenta. Two cavities form in the inner layer of trophoblast cells; the walls of these cavities give rise to two more embryonic membranes - amnion and yolk sac. Amnion is a thin shell that covers the embryo and performs protective functions; its cells secrete amniotic fluid, filling the amniotic cavity located between the amnion and the embryo. As the embryo grows, the amnion expands so that it is always pressed against the wall of the uterus. Amniotic fluid supports the embryo and protects it from mechanical damage. The yolk sac in the human embryo does not play a significant role; it is a kind of rudiment (the yolk sac is especially developed in reptiles and birds; it absorbs the nutrients stored in the yolk and transfers them to the midgut of the embryo). In humans, the yolk sac contains practically no yolk; its main function is hematopoiesis. In addition, primary germ cells are formed in its wall, then migrating into the rudiments of the gonads.

Embryonic period

Embryonic period lies in the flow gastrulation and education three germ layers, histogenesis (tissue formation) and organogenesis (organ formation).

Gastrulation is the process of formation of germ layers. The disc-shaped embryoblast is called germinal disc. An embryo develops from it. The cells of this disc at an early stage, when its diameter does not reach 2 mm, differentiate into two germ layers (leaves) - ectoderm and endoderm. At a later stage it is formed mesoderm. These three germ layers give rise to all the tissues of the developing embryo. At the end of gastrulation in the 4th week, primordia are formed neural plate And chords.

In the early stages of development, the exchange between the embryo and the maternal organism occurs due to the trophoblast villi, and then the fourth shell develops - allantois. The allantois grows outward until it comes into contact with the chorion, forming a structure rich in blood vessels that participates in the formation of the placenta.

Placenta has the form of a disc fixed in the uterine mucosa, and from the 12th week of development it completely ensures the exchange between the fetus and the mother. By the end of the eighth week, all internal organs are formed. In the placenta, the blood of mother and fetus does not mix. Between the body of the fetus and the placenta is formed umbilical cord, in which two umbilical arteries, carrying venous blood from the embryo, and one umbilical vein, carrying arterial blood from the placenta to the embryo. Tissues are formed and differentiated from the cellular material of embryonic rudiments. This ends the embryonic period. An eight-week embryo is 3-3.5 cm long and weighs about 4 grams. His neck is separated, facial features are outlined, limbs and external genitalia are formed.

Fetal period begins from the 9th week of intrauterine life with a predominance of growth processes and final tissue differentiation. By the end of 3 months, the fruit weighs about 40 grams, its length reaches 8-9 cm. Ossification nuclei appear in almost all bones. In the 4th month, individual facial features are formed. At the 5th month, the skin becomes covered with fluff, and the movements of the fetus are felt by the mother. The fetal heartbeat is heard, which is faster than that of the mother. At 6 months, the embryo is 30 cm long and weighs 650-700 g. In the case of premature birth at 7 - 8 months, the fetus is viable, but needs the conditions of intrauterine life. By the end of the 9th month, the fuzz on the skin is lost, but a layer of cheese-like lubricant remains, the nails protrude above the fingertips, the arms are longer than the legs, and in boys the testicles descend into the scrotum. The weight of the fruit is about 3.5 kg and the length is 50 cm.

Fetal development ends childbirth(expulsion of the fetus and placenta from the uterus). The onset of labor is associated with the release of a hormone from the pituitary gland oxytocin, causing strong contractions of the muscles of the uterus and abdominal muscles. The baby is pushed into the pelvis and is born. The first sign of pulmonary respiration is a cry. After 15-20 minutes, the placenta and amniotic membrane are separated from the uterine wall and pushed out.

During the process of embryogenesis, various factors (poisons, radiation, vitamin deficiencies, oxygen starvation, etc.) can affect the developing organism and cause developmental deviations in the form of anomalies and deformities. Violation of living conditions is especially dangerous if it coincides with periods of increased sensitivity of the embryo, the so-called critical periods of embryogenesis.

In humans, the 7th day, 7th week and childbirth are considered critical periods. Therefore, a pregnant woman must be protected from any adverse effects from the very first days of pregnancy.

Extrauterine (postembryonic) period.

Lasts from birth to death extrauterine (postembryonic, postnatal) development.

Its following periods are distinguished (the periodization of ages was adopted at the VII International Symposium on Problems of Age-Related Morphology, Physiology and Biochemistry in 1965):

• newborn(first 1 - 10 days after birth),
• chest(from 10 days to 12 months),
• early childhood(from 1 to 3 years),
• first childhood(from 4 to 7 years old),
• second childhood(from 8 to 12 years old),
• adolescence(from 13 to 16 years old),
• adolescence(from 17 years old to 21 years old),
• period of maturity(from 22 years to 55 -60 years),
• elderly age(from 56-61 years to 74 years),
• old age(75 – 90 years)
• centenarians ( over 90 years).

The most intensive growth and development of a child is observed in the first year of life and during puberty. During the process of growth and development, the proportions of the body change. For example, the ratio of head to body size in a newborn is 1:4, while in an adult it is 1:8.

The main features of humans in comparison with animals are the presence of thinking, speech and motor activity, which is closely related to work activity. For the development of these functions, proper upbringing of children aged 2 to 4 years is very important. The period from 7 to 18 years of age is a crucial period for physical, mental and moral development person.

Return to Human Development

Development of the human body. Individual human development (ontogenesis) begins from the moment of fertilization, when the fusion of female (egg) and male (sperm) germ cells occurs. Initial stages development occurs in the woman’s genital tract, so all ontogenesis is usually divided into prenatal and postnatal (from the Latin natus - childbirth) periods, i.e. prenatal and postnatal.

In the prenatal (intrauterine) period of ontogenesis, in turn, the germinal (embryonic) and fetal (fetal) periods are distinguished. The first lasts 2 months, the second - from the 3rd to the 9th inclusive.

The process begins from the moment of birth independent life the individual and his adaptation to the environment. Newly acquired characteristics are layered on those inherited, as a result of which complex transformations occur in the body.

The physical development of an individual is characterized by weight, height and size of individual parts of the body.

These indicators change unevenly throughout life.

Accelerated growth is observed during early childhood (from 1 to 3 years), at the ages of 5 to 7 years and during puberty (from 11-12 to 15-16 years), while the basic proportions of the body also change. In parallel with growth, there are observed age-related changes in all organs and systems. Around the age of 20-25, a person’s growth stops and a relatively stable period of existence begins - adulthood. After 55-60 years, a person begins to gradually age, and sclerotic changes occur in a number of organs. This in turn causes a decrease in various body functions.

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Before late XIX V…

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Chapter 4. Main directions of the evolution of ontogenesis

The essence and structure of natural science

The emergence of science and the main stages of its development.

In everyday language, the word “science” is used in several senses and means: - a system of special knowledge; - type of specialized activity - public institution(a set of specialized institutions...

What is natural science and how it differs from other cycles of science

2.

Main stages in the development of natural science

The main stages in the development of natural science can be distinguished based on various considerations. In my opinion, the dominant approach among natural scientists to the construction of their theories should be considered as the main criterion...

Embryonic development

2. Stages of development

Once the egg meets the sperm in the fallopian tube, they unite and fertilization occurs. The fertilized egg moves through the fallopian tube and then attaches to the wall of the uterus. This takes 7-10 days...

Stages of ontogenesis of higher plants

I. Stages of ontogenesis of higher plants

Stages of development of natural science and society

1.1 Main stages in the development of natural science and society

At all stages of the development of human cognition, there is a complex interrelation between the results of research in society and the natural sciences. Primary knowledge about the world, accumulated over many centuries of primitive tribal society...

Stages of individual human development

Development of the human body. Individual human development (ontogenesis) begins from the moment of fertilization, when the fusion of female (egg) and male (sperm) germ cells occurs. The initial stages of development occur in the woman’s genital tract, so all ontogenesis is usually divided into prenatal and postnatal (from the Latin natus - childbirth) periods, i.e. prenatal and postnatal.

In the prenatal (intrauterine) period of ontogenesis, in turn, the germinal (embryonic) and fetal (fetal) periods are distinguished. The first lasts 2 months, the second - from the 3rd to the 9th inclusive.

In the embryonic period, there is an increase in the number of cells, which gradually differentiate into the rudiments of all types of tissues (histogenesis). During the second month of intrauterine development, organs are formed (organogenesis); The main parts of the body are formed: head, neck, torso and limbs. From the 3rd month, intensive growth and development of the fetal body begins, which continues after the birth of the child.

From the moment of birth, the process of independent life of the individual and his adaptation to the environment begins. Newly acquired characteristics are layered on those inherited, as a result of which complex transformations occur in the body. The physical development of an individual is characterized by weight, height and size of individual parts of the body.

These indicators change unevenly throughout life.

Accelerated growth is observed during early childhood (from 1 to 3 years), at the ages of 5 to 7 years and during puberty (from 11-12 to 15-16 years), while the basic proportions of the body also change. In parallel with growth, age-related changes are observed in all organs and systems. Around the age of 20-25, a person’s growth stops and a relatively stable period of existence begins - adulthood. After 55-60 years, a person begins to gradually age, and sclerotic changes occur in a number of organs. This in turn causes a decrease in various body functions.

From the moment of birth, the process of independent life of the individual and his adaptation to the environment begins. Newly acquired characteristics are layered on those inherited, as a result of which complex transformations occur in the body. The physical development of an individual is characterized by weight, height and size of individual parts of the body. These indicators change unevenly throughout life.

Accelerated growth is observed during early childhood (from 1 to 3 years), at the ages of 5 to 7 years and during puberty (from 11-12 to 15-16 years), while the basic proportions of the body also change. In parallel with growth, age-related changes are observed in all organs and systems. Around the age of 20-25, a person’s growth stops and a relatively stable period of existence begins - adulthood. After 55-60 years, a person begins to gradually age, and sclerotic changes occur in a number of organs. This in turn causes a decrease in various body functions.

In the process of development and growth of the body and the formation of its nervous system, the nature and level of human needs changes. A newborn is dominated by vital needs associated with the implementation of vital functions: nutrition, breathing, sleep, etc. Various physiological needs are gradually formed and intensively developed associated with movement in space, with the absorption of various nutrients, growth and development, as well as independent performance and voluntary regulation of physiological functions. Relatively early, already in the first year of life, cognitive needs begin to form, especially during early childhood (1-3 years) and later during the preschool and school periods of the child’s development. The formation of social and communicative needs takes a rather long period of ontogenesis, including mature life individual.

During puberty, social and communicative needs dominate in the development of a subject’s personality. The pinnacle of personal development is the creative needs associated with the accumulation of new knowledge and cultural values. The beginning of the formation of these needs should be attributed to the end of early childhood and the transition to the preschool period of development. However, they can become the dominant motivational basis later, when a person’s personality has already been formed and a period of mature existence begins.

Introduction

Human physical development is a complex of morphological and functional properties of the body, which determine the shape, size, weight of the body and its structural and mechanical qualities.

Signs of physical development are variable. Physical development of a person is the result of the influence of hereditary factors (genotype) and environmental factors, and for a person - the entire complex social conditions(phenotype). With age, the importance of heredity decreases, the leading role passes to individually acquired characteristics.

The physical development of children and adolescents is related to growth. Each age period - infancy, childhood, adolescence and youth - is characterized by specific features growth of individual body parts. At each age period, the child’s body has a number of characteristic features unique to this age. Between the body of a child and an adult there are not only quantitative differences (body size, weight), but also, above all, qualitative ones.

Currently, there is an acceleration in human physical development. This phenomenon is called acceleration.

In my work, I will try to briefly characterize each of the main stages of individual human development.

The main stages of individual human development

When studying human development, his individual and age-related characteristics in anatomy and other disciplines, they are guided by scientifically based data on age periodization. Scheme of age periodization of human development, taking into account anatomical, physiological, social factors, was adopted at the VII Conference on Problems of Age-Related Morphology, Physiology and Biochemistry (1965). It distinguishes twelve age periods (Table 1).

Table 1

Individual development, or development in ontogenesis, occurs during all periods of life - from conception to death. In human ontogenesis, two periods are distinguished: before birth (intrauterine, prenatal - from the Greek natos - born) and after birth (extrauterine, postnatal).

The following periods of post-embryonic development of a child are distinguished: the neonatal period, the infancy period, early childhood (nursery period), preschool and school periods. The formation of the body ends by the age of 22–25.
- Neonatal period (first 4 weeks of life). The position of the newborn resembles the position of the fetus in the uterus. He sleeps most of the day, waking up only at feeding time. The child develops most harmoniously with natural breastfeeding.
- Breast period (from the 5th week to the end of the 1st year of life). Many changes occur in the child’s motor system: at the end of the 1st month of life he tries to straighten his legs, at the 6th week he lifts and holds his head, at the 6th month he sits, at the end of the 1st year of life he tries to take his first steps. The child’s psyche also develops intensively. At the 2nd month, he smiles at the sight of bright objects, when his mother appears, by the 4th month he takes toys into his mouth, examining them, begins to distinguish between adults. By the end of the 1st year of life, the child begins to understand many of the parents' phrases.
- Early childhood period (from 1 to 3 years). The child is actively developing motor skills. He begins to walk, masters various ways of manipulating objects. During this period, the child develops a desire to understand the world and a desire for self-affirmation.
- Preschool period (from 3 to 6 years). Children show great interest in the world around them - this is the stage of questions, or the “why” age. The period from 2 to 4 years is especially important for the development of thinking, speech and work activity. If it is missed, then a lag in mental and physical development occurs.
- School period (from 6 to 17–18 years), including puberty. There is a qualitative change in all human activities. Primary schoolchildren perform complex and precise movements slowly and with difficulty. The final formation of motor activity ends by the age of 18. A physiological feature of the adolescent’s cardiovascular system is that the growth of blood vessels (their cross-section) lags behind the growth of the heart, which often leads to circulatory disorders, dizziness, high blood pressure, and cardiac dysfunction. This is especially pronounced during puberty: in adolescents, excitability increases, increased irritability occurs, and sleep disturbances occur. The increased release of hormones keeps the body in a state of high activity. Major changes occur in the structure and functioning of the body. By age 18, most physiological functions young man approaches the functions of an adult.