Presentation on the topic of prenatal ontogeny. Individual human development or ontogeny. before birth or exit from the embryonic

SGBOU PO

"Sevastopol Medical College

named after Zhenya Deriugina

Teacher Smirnova Z. M.

Relevance of the topic

Modern embryology studies not only the stages of embryogenesis,

but also tries to explain why development proceeds this way and not otherwise: why does one cell give rise to a variety of cell types characteristic of an adult organism? What determines the course of development? There are much more questions posed by scientists than answers, and this naturally reflects the increased interest in embryology, a science that has been developing especially rapidly in recent years.

The most important applications of embryology for humanity are in the field of medicine. The problem of intrauterine development anomalies (teratogenesis) has acquired international status.

DEVELOPMENT OF EMBRYOLOGY

The question of individual development - ontogenesis has attracted attention since the time of Aristotle.

In the XVII-XVIII centuries. two views on ontogeny took shape - preformation and epigenesis.

PREFORMISM

Supporters of preformism believed that embryonic development is reduced to the growth of the formed embryo.

The preformers divided into two groups.

ovists it was believed that the already formed embryo is in the egg, and the masculine principle only gives impetus to development.

Animalculists They argued that the embryo is enclosed in a spermatozoon, which develops at the expense of the nutrients of the egg.

EPIGENETICS

Adherents alternative course - epigenetics- it was believed that in the process of ontogenesis, the structures and organs of the embryo are formed from a structureless substance. The idea of ​​epigenesis is first encountered in the writings of W. Harvey (1651), but the corresponding views were fully expressed K.F. wolf (1733-1794

Conceptual illustration

16th century of what Aristotle's epigenesis would look like

The decisive turning point in the dispute between representatives of the two currents occurred in the 19th century. after the work of K. M. Baer.

K. Baer believed that no neoplasms occur in the embryo, only transformations take place: from the simpler and undifferentiated to the more complex and differentiated.

Individual development of organisms (ontogenesis)

Ontogeny - the individual development of an individual, begins with the formation of a zygote (during sexual reproduction) and ends with death.

There are three types of animal ontogeny:

Larval (indirect development

Intrauterine type of development

Larval type of development

Larval (indirect development, accompanied

metamorphosis ) found in invertebrates, fish,

amphibians.

• Larval formation

due to small

reserves of yolk in eggs.

• The larva differs from

adult

• structure,
• lifestyle,
• habitat.

• They have a number of provisional

(temporary) bodies,

which subsequently

disappear (gills and tail

at the tadpole).

Oviparous type of development

Oviparous (non-larval) type of development observed in a number of invertebrates, reptiles, birds and oviparous mammals, whose eggs are rich in yolk.

• Characteristically long

embryonic development in

egg.

• Nutrition, breathing and

other functions in embryos

carried out

supervisory authorities -

germinal membranes:

amnion, allantois, etc.

amniotic fluid

embryo

amnion

O 2

SO 2

allantois

chorion

yolk sac

shell membrane

yolk

Intrauterine type of development

Intrauterine type of development characteristic of higher mammals,

• eggs

which contain

little nutritional

material.

• Vital

functions

germ

carried out

through maternal

organism

(placenta).

Periods of ontogeny

The ontogeny of multicellular organisms is divided into two periods

Postembryonic -

begins at birth or exit from egg membranes and ends with death

Embryonic -

starts with education

zygote and ends

exit from egg shells

or the birth of an organism.

Includes stages:

Direct Indirect:

- incomplete and

- complete metamorphosis

Histo- and organogenesis

Splitting up

gastrulation

Embryonic period

begins with the formation of a zygote

nucleus

cytoplasm with yolk inclusions

sperm penetration

Fusion haploid

nuclei of two gametes

Zygote

Embryonic period

Embryonic includes the processes of crushing, gastrulation, histo- and organogenesis:

Histo- and organogenesis – formation of tissues and organs.

In chordate embryos, axial organs are formed:

neural tube, notochord and intestinal tube

Splitting up

characterized by education

multicellular

single layer

embryo - blastula stage

Gastrulation -

education

2 or 3

ply

germ

Embryonic period. crushing stage

Cleavage is a process of mitotic divisions of the zygote, characterized by the absence of the growth stage of blastomeres, as a result of which the first stage of a multicellular embryo, the blastula, is formed. In the process of crushing, the volume of the embryo does not change, and the sizes of its constituent cells become smaller with each division.

Thus, during crushing, a multicellular single-layer embryo (blastula) with a cavity inside is formed.

After the formation of the blastula, the process of gastrulation begins.

gastrulation

– the process of formation of germ layers (ecto-, meso- and endoderm).

• In two-layer organisms, only ecto- and endoderm are formed;
• In 3-layer organisms: ecto-, ento- and mesoderm.

• Lancelet gastrulation

carried out through

invaginations - invaginations

blastoderm to blastocoel;

• A two-layer

embryo - gastrula;

• outer layer of cells

ectoderm, inner

endoderm;

• Cavity within the gastrula

gastrocoel;

• Mesoderm is formed

from endoderm cells.

Gastrulation of 2-layer organisms

Blastocoel

Endoderm

ectoderm

Blastula gastrulation gastrula

Gastrulation of 3-layer organisms

ectoderm

Endoderm

Gastrocel

Mesoderm formation

Blastopore (primary mouth)

Intussusception

Splitting up. gastrulation

INTUSSUSCEPTION

There are four ways of formation of ecto- and endoderm

Epiboly, or fouling - small cells of the animal pole are overgrown

large outside

cells of the vegetative pole. Occurs in amphibians with telolecithal eggs.

Delamination,

or bundle - embryonic cells divide parallel to the surface of the embryo, resulting in the formation of the outer and inner germ layers. Typical for insects, birds, reptiles.

Immigration - characterized by the movement of blastoderm cells into the blastocoel.

Seen in intestinal

Invagination, or invagination - observed in animals with isolecithal type of eggs.

Histo- and organogenesis

– process of formation of organs and tissues

• Neurulation is this initial stage organogenesis resulting in formation of axial organs:

• neural tube,
• chords and
• secondary intestine.

• An embryo at the stage of neurulation is a neurula.

• Neural tube - ectoderm cells on the dorsal

side of the body I bend, forming a groove, the edges of which gradually close.

• Chord - formed as a result of separation

dorsal part of the endoderm, located under

nerve germ.

• Intestinal tube - formed from the endoderm in

as a result of transformation of the gastrocoel.

Histo- and organogenesis

Neurulation

Organogenesis

In the further development of animal embryos, the rudiments of various tissues and organs are laid down from the cells of one of the three germ layers of the ectoderm, endoderm, or mesoderm.

germ layer

Organs and tissues

Integuments with their derivatives: skin glands, hair, feathers, scales.

Sense organs, nervous system, epithelium of the anterior and posterior intestines.

ectoderm

Notochord, epithelial lining of the middle intestine, as well as intestinal glands, liver, pancreas. Lungs of land animals.

Endoderm

Most of the internal organs. Skeletal muscles, bone, cartilage and connective tissues, circulatory system, excretory organs, various parts of the reproductive apparatus, etc.

mesoderm

Provisional (temporary) organs of the embryo -

ensure the viability of the embryo.

Chorion (serous membrane) - the outer shell adjacent to the shell or maternal tissues.

Serves for metabolism with environment.

Amnion - a bag filled with a liquid that creates an aquatic environment and protects the embryo from drying out and damage.

Allantois - participates in gas exchange, a receptacle for urea and uric acid. In mammals, together with the chorion, it forms the placenta. Vessels grow from the allantois to the chorion, with the help of which the placenta performs excretory, respiratory and nutritional functions.

The yolk sac is involved in the nutrition of the embryo and is a hematopoietic organ.

Until the 6th week after fertilization, the yolk sac plays the role of the “primary liver”.

amnion

amniotic fluid

embryo

O 2

SO 2

allantois

chorion

yolk sac

shell membrane

yolk

Embryonic induction

Embryonic induction -

the interaction of parts of the developing embryo, in which one part of the embryo affects the development of another part.

In the experiments of the German scientist H. Spemann (1924) on newt embryos, a piece of the embryo from the region of the upper lip of the blastopore at the gastrula stage of the newt is transplanted onto the lateral or ventral side of the gastrula of another embryo. At the transplant site, the development of the neural tube, notochord and other organs occurs. Development may reach stages with the formation of an additional embryo on the lateral or ventral side of the recipient embryo.

Upper lip of the blastopore

Embryonic induction -

Conclusions:

• A section taken from the dorsal lip of the blastopore

capable of directing the development of cells that are around him, on a certain path

development. It sort of organizes, or induces,

embryonic development.

• The exact structure of the newly formed organs in place transplantation indicates embryonic regulation.
• G. Spemann called the dorsal lip of the blastopore

primary embryonic organizer or primary embryonic inductor, and the very

a phenomenon in which one part of the embryo

affects the fate of another, the embryonic by induction

2 blastomeres

uterus

• Embryonic

human development

can be divided

for 3 periods:

• elementary

(1st week of development);

2) germinal

(2-8 weeks);

3) fetal

(from the 9th week

development to

birth of a child).

The process of intrauterine development of the human embryo lasts

280 days.

8 blastomeres

morula

zygote

egg

Fertilization

eggs

(1 day)

blastula

endometrium

Implantation

Human embryonic development

polar body

embryoblast

blastocoel

pronuclei

Tropho blast

blastomere

Day 3 - morula

2 day - crushing

Day 4 - differentiation

day 1 - fertilization

Day 5

epiblast

hypoblast

trophoblast

endometrium

embryoblast

Germ disk

Day 9 - differentiation

Day 7 - implantation

Day 6

day 12

umbilical cord

Extraembryonic coelom

amniotic cavity

amnion

day 12

embryo

mesoderm

ectoderm

mesoderm

intestine

yolk sac

chorion

endoderm

day 18

Day 23

Human embryonic development

• The function of the outer germinal membrane is performed by the chorion, or villous membrane. The chorionic villi grow into the lining of the uterus.

• The place of the greatest branching of the chorionic villi and their closest contact with the surface layers of the endometrium of the uterus is called the placenta (children's place).
• The placenta is a temporary organ found only in placentals.

• The connection of the body of the embryo with the placenta is carried out through the umbilical cord or umbilical cord (dense strand 40 cm long), containing blood vessels. Vessels are formed in the allantois, go from the fetus to the wall of the uterus.

amniotic fluid

chorion

amnion

placenta

umbilical cord

uterine wall

Human embryonic development

• The main functions of the placenta are trophic, excretory, endocrine, protective.
• Maternal and fetal blood does not mix. Between them there is a placental barrier. Nutrients and O 2 , dissolved in maternal blood, diffuse through the placental barrier into the blood of the fetus, ensuring the life and growth of the fetus before birth. end products

fetal metabolism pass through the placenta into the mother's blood and are excreted by the mother's excretory system.

Antibodies, hormones, drugs, drugs, poisons and other substances penetrate the placental barrier.

twin education

Distinguish

Monozygotic

(identical) twins

develop from one

fertilized

eggs.

• Have the same genotype

but may differ in

phenotype due to

factors

external environment.

• Always the same sex
• they have the same group

blood, eye color,

• dermatoglyphic patterns

and etc.

dizygotic

(binary)

twins develop

after fertilization

spermatozoa

several

simultaneously

mature eggs.

They have different genotypes and

their phenotypic

differences are due to

genotype, and

external

environment.

Polycellular

ovulation

Mature egg

Monozygotic

Twins

dizygotic

Fertilization

2morulas

Implanted

2 blastocysts

2 placenta

1 placenta

amniotic sac

amniotic sac

Siamese twins

Conjoined (or Siamese) twins are monozygous, therefore they have the same genotype and are always of the same sex.

Conjoined twins appear if splitting is delayed

up to 13 days after conception.

According to modern research, genetic and

environmental influences, as well as exposure to toxic substances.

In Siam (now Thailand)

in 1911, the twins Eng and Chang were born to a Chinese mother. They had fused chest cartilages

Critical periods of embryogenesis -

periods of greatest sensitivity of the embryo to

the influence of environmental factors, as they change

conditions of its existence and new blocks of genes are included.

A person has 3 critical periods:

1.Implantation - implantation of the embryo into the mucosa

uterus (6-7 days after fertilization);

2. Placentation - placenta formation (14-15 days);

3. Childbirth – (39-40 weeks).

2. Placentation

3. Childbirth

1.Implantation

Critical periods of embryogenesis

• Critical periods coincide

• with active cell differentiation and
• with the transition from one period of development to another,
• with a change in the conditions for the existence of the embryo.

In mammals blastula implantation characterized by a transition to new conditions of nutrition and gas exchange.

Development of the placenta and the transition to placental nutrition and gas exchange requires new adaptations.

After childbirth the newborn must adapt to drastic changes in the conditions of existence and restructure the activity of all body systems.

Changing the methods of nutrition and gas exchange increases the sensitivity of the embryo to adverse environmental factors.

Teratology is the science that studies deformities

Factors causing pathology of intrauterine development of the fetus

Physical factors of the environment:

• all kinds

ionizing

radiation,

• heavy

metals;

• flaw

oxygen

Bad habits:

• alcohol,
• drugs,
• smoking.

Chemical factors of external

environments:

• Medicinal

drugs,

• flaw

excess

vitamins

Mother's illnesses:

• diseases

internal

and genital

organs;

• violation

exchange

substances

Maternal infections:

• rubella,
• toxoplasmosis,
• herpes virus,
• HIV, etc.

Postembryonic development

– the development of an organism from the moment of exit from the egg membranes (with larval development) or birth (with intrauterine ontogenesis) to death.

• Development can be direct or indirect

(with metamorphosis).

• Metamorphosis characteristic of the larval

ontogenesis, it can be complete and incomplete.

Types of postembryonic development

direct development

Indirect development (with metamorphosis)

With incomplete metamorphosis:

• egg
• larva
• sexually mature

individual

With complete metamorphosis:

• egg
• larva (caterpillar)
• chrysalis
• sexually mature

individual

oviposition

with big

quantity

Yolk (reptiles, birds)

intrauterine

development

(mammals)

hatched from egg shells or newborn creatures differ from the adult form mainly in size, as well as underdevelopment of a number of organs and body proportions.

In the larva, the organs necessary in the mature state are absent or undeveloped,

there are supervisory authorities.

In some animals, the larvae are similar to adult organisms (grasshoppers).

Postembryonic development

Postembryonic ontogeny of animals and humans

includes periods:

• Pre-reproductive period, or juvenile (before

puberty) - the period of growth and development of the body;

• Reproductive period, or mature (puberty state) - associated with the possibility of self-reproduction, reproduction.

The period of active functioning of an adult organism;

• Post-reproductive, or old age ,

ending in natural death.

Topic:

The purpose of the lesson: expand students' knowledge of the process

fertilization, patterns and stages

embryonic development, methods of post-embryonic

development.

• Gametogenesis
• Ovogenesis
• spermatogenesis
• sexual reproduction
• Vegetative propagation
• Parthenogenesis
• Strobilation or fragmentation.

Learning new material.

Ontogenesis - the individual development of a living organism from the moment of birth to death.

Ontogenesis divided into 2 periods:

• Embryogenesis - development of the embryo from the moment of zygote formation to birth
• Postembryogenesis - development after birth and before death, i.e. after the embryonic stage.

The development of the body from the moment of fertilization

before birth or exit from the embryonic

shells.

Stages:

• Cleavage of the zygote.

2. Blastula formation.

3. Gastrulation.

Embryogenesis

– fertilization cell

– lump of blastomeres at the initial stages of crushing

blastula

– multicellular unilamellar embryo

gastrula

– two-layer, then three-layer embryo

- an embryo with a complex of axial organs: neural tube, notochord, intestinal tube.

histogenesis

organogenesis

crushing

blastomeres

During cleavage, the number of cells

grows rapidly, they become smaller and

smaller and form a sphere, inside

which creates a cavity blastocoel .

From this moment the embryo is called

Blastula (single-layer embryo) .

How do blastomeres divide and what set of chromosomes

contained in their nuclei?

stage

gastrulation

ectoderm

ectoderm.

ectoderm

endoderm

primary mouth

secondary cavity

body

In which animals does embryonic development end at this stage?

mesoderm

neurula

histogenesis

organogenesis

What is shown under the numbers 2 and 3?

Neirula .

Organogenesis

germ layers

• ectoderm – outdoor
• mesoderm - average
• Endoderm - internal

Scheme of development of germ layers

germ layers

Bookmark stages

ectoderm

Formation of tissues and organs

Blastula

Endoderm

mesoderm

skin derivatives :

glands (sebaceous, sweat, milk), hair, nails, horns and hooves in animals.

nervous system and

sense organs

ectoderm

integuments in animals

skin epidermis

tooth enamel

endoderm

all glands except skin

pancreas

respiratory system

digestive organs

circulatory system

musculature

mesoderm

excretory system

reproductive system

Characteristics of the germ layers

germ layers

Bookmark stages

ectoderm

Formation of tissues and organs

Blastula

Endoderm

Tissues of the nervous system, integument, sweat and sebaceous glands, tooth enamel, perceiving cells of the sense organs

mesoderm

Epithelial tissues, glands of the gastrointestinal tract, liver and pancreas

Connective tissue, skeletal muscle, excretory organs, blood vessels, intestinal smooth muscle, respiratory and urogenital tract, heart, GI

The development of the organism from the moment of birth or

exit from the embryonic membranes to death.

may be

direct

indirect

Direct postembryonic development:

An organism of small size comes out of the egg shells or from the mother's body, but with all the main organs already laid down, which are characteristic of an adult animal.

Name examples of animals with direct postembryonic development.

mammals

birds

reptiles

Indirect postembryonic development:

A larva emerges from the egg, usually arranged more simply than an adult animal, with special larval organs that are absent in the adult state. Over time, the organs of the larva are replaced by organs characteristic of adults. The larva turns into an adult animal.

What is development with transformation called?

What animal is it typical for?

amphibians

fish

insects

crustaceans

shellfish

worms

The most striking development with metamorphosis

presented in insects.

Development with full transformation:

egg

larva

chrysalis

imago

name

what stages

in his

development

passes

butterfly?

What insects are characterized by this type of development?

Development with incomplete transformation:

Looking at the picture, determine what stages of development go through

insects with incomplete metamorphosis? What stage is missing?

egg

larva

imago

Which insects are characterized by development with incomplete metamorphosis?

The individual development of the organism studies embryology

(from Greek. « embryonic » - germ)

Brief history reference

Academician of the Russian Academy

Karl Maksimovich Baer

(1792 -1876)

founder of modern embryology

All multicellular organisms develop from a fertilized egg. The development of embryos in animals belonging to the same type is largely similar. These facts support the validity

the law formulated by K. Baer germline similarity:

"Embryos show, already from the earliest stages, a certain general resemblance within the phylum."

Carl Baer

There is a deep connection between the individual development of organisms and their historical development, which is reflected in biogenetic law , formulated by two German

scientists F. Müller and E. Haeckel in XIX century:

ontogenesis (individual development) of each individual is a brief and quick repetition of the phylogeny (historical development) of the species to which this individual belongs.

Fritz Müller

Ernst Haeckel

Influence of environmental factors on the embryo

From the first hours of its development, each embryo is extremely sensitive to the adverse effects of environmental factors.

Habitat factors

Biotic

abiotic

Humidity, temperature, pressure, radiation, chemicals.

Viruses, bacteria, fungi, animals, plants

• Contribute to the preservation of a normal ecological situation;
• Not to worsen not now nor in the future the ecology of the native land;
• Do not drink alcoholic beverages;
• Do not smoke;
• Do not take drugs;
• Eat well;
• Do sport

Development processes

Quantitative Process:
Growth is the quantitative process of increasing the number of cells or
cell sizes
Quality processes:
tissue differentiation and
bodies
shaping

The relationship of these processes

Accelerated growth slows down
shaping,
differentiation and development
secondary sexual characteristics
Enhanced sexual processes
development inhibit the growth of the body and
growth muscle mass

Development

Programmed by the genetic
information
Regulated by internal factors
(hormones and biologically active substances)
Defined:
lifestyle (nature of nutrition, level
physical and mental stress and
etc.)
upbringing
state of the emotional sphere
health level
the influence of the external environment

"Age periods" - periods characterized by functional, biochemical, morphological and psychological characteristics

Periodization is based on the complex
signs:
Body and organ sizes, weight and
skeletal ossification (bone age)
Teething (dental age)
Development of endocrine glands and
degree of puberty

Ontogenesis

Prenatal period (up to
birth):
Embryonic (up to the 8th week)
Fetal - fetal (from 8 weeks to
birth)
postnatal period (after
birth)

Postnatal period of ontogenesis:

Neonatal period (neonatal)
Early neonatal (0-7 days)
Late neonatal (8-28 days)
Postneonatal (29 days-12 months)
Early childhood -1-3 years
First childhood - 4-7 years
Second childhood (M - 8-12 years old, D - 8-11 years old)
Adolescence (M - 13-16 years old, D - 12-15 years old)
Youth age (M - 17-21 years old, F - 16-20 years old)
Mature age - 1st period (M - 22-35 years old, F - 21-35 years old)
Mature age - 2nd period (M - 36-60 years old, F - 36-55 years old)
Old age - (M - 61-74 years old, F - 56-74 years old)
Senile age - (75-90 years)
Long-livers - 90 years and older

Breast age

By year:
body length increases by 1.5 times
body weight - 3 times
at 6 months - the first teeth
Psychomotor skills:
Holds head - from 1 month
Sitting - from 6 months
Creeps - from 8-10 months
Walking - from 12 months

Breast age

Loss of passive immunity
The ability to produce
conditioned reflexes on the complex
irritants, incl. - on word
The beginning of speech (by the year 10-12 words)
The need for communication develops
The beginnings of intellectual
activities, thinking
The trend towards targeted
activities

Early childhood -1-3 years

By the age of 2, eruption ends
milk teeth
After 2 years absolute and relative
body size gains
decrease
Muscle mass increases rapidly
The main fund of movements is laid
Objective action is developing, game
activity
Passive speech becomes active
Develops visual-active thinking
Personality begins to form

First childhood - 4-7 years

From the age of 6, the first molars appear
First physiological traction
Increase in limb length, deepening
facial relief
Perfection of fine coordinated
movements
Development of all types of internal inhibition
Dominant verbal thinking with
inner speech
Visual Action Thinking
Needs and volitional qualities are formed
The leading type of activity is a game that develops
arbitrary memory and attention, speech and
thinking

Second childhood

Sex differences in form are revealed
and body weight
Increased growth in length begins
Increased secretion of sex hormones
and begin to develop secondary
sexual characteristics:
In girls: the formation of the mammary glands,
development of the uterus and vagina, hair growth
pubis, armpit hair
In boys: growth of testicles, scrotum, and penis

Second childhood

Abstract thinking
Dynamic stereotypes are easy
are being remade
Conditional conditions are quickly developed Complete
replacement of milk teeth with permanent ones
Complex coordination systems develop rapidly
movement (letter)
Pronounced influence of the cortex over subcortical
formations - restraint of emotions,
meaningfulness and controllability of behavior
Increases mental performance
reduced fatigue
Reflexes are formed that are resistant to external
braking

"Puberty Leap" - an increase in all
body size
Completion of the formation of secondary
sexual characteristics:
For girls: completion of formation
mammary glands, pubic hair and
armpits, the appearance of menarche
In boys: voice mutation, pubic hair
and armpits, the appearance of the first
wet dreams

Adolescence (pubertal) age

Growth jump with some characteristic
disharmony, the emergence and development of traits,
gender specific
The processes of excitation prevail over the processes
braking
Lots of extra moves
Decreased cortical control over emotional responses
memory, perception, attention
Instability of the emotional state
Decreased mental performance
Mental imbalance occurs
An abstract-logical type of thinking is being formed and
ability to operate with hypotheses

Youth age:

The growth process ends
Dimensional features reach the definitive
quantities
There is a sharp increase in physical and mental
performance
The role of the cortex in the regulation of mental
activities and emotional control
The possibility of internal
braking
There is differentiation between functions
right and left hemispheres
Work strategy mechanisms are being worked out
brain, incl. the most economical way

Periods:

critical
intermittent
moments of development
organism,
individual bodies
and fabrics
Switching
organism on
new level
ontogeny
Creation
morphofunctional basis
existence in
new conditions
vital activity
controlled
genetically
sensitive
Particularly sensitive periods
occur during critical
Less genetic control
Fit functions
body to new conditions
Optimization of perestroika
processes in organs and systems
Coordination of activities
functional systems
Ensuring adaptation to
loads on a new level
the existence of an organism
Greater influence of the external environment
(including pedagogical and
coaching)

Acceleration -

this is a "epoch-making" increase in growth
children and early puberty
(accompanied by an increase
life expectancy and
reproductive period)
Due to:
genotype change due to
population migration and education
mixed marriages
level of social conditions

Retardation - delay, stop in development

Involution - aging, reverse
development (thymus gland -
after puberty,
mammary glands - in the elderly
age)

Features of energy exchange in children

Increased heat dissipation
High energy intensity
processes
Imperfection of all body systems
With age, the total exchange per kg of body weight
decreases, in absolute terms increases
In the fetus and newborn - anaerobic way
glucose utilization - gluconeogenesis,
later - an increase in the role of aerobic processes
Maximum oxygen consumption - to 17
years

Age features of blood

With age, circulating blood volume
relative to body weight and the number of red blood cells
decreases
Hemoglobin by the year decreases to 116 g.l, up to 14 years
- 10-20 g less. than an adult
The number of leukocytes in a newborn is 30 thousand, then
decreases. At 14-17 years old - as in adults
In the leukocyte formula: the first "cross"
(the number of neutrophils is equal to the number of lymphocytes) by 5-6
day, the second - at 5-6 years old, by 17 years old - as in adults
After a year, the content of clotting factors and
anticoagulants - as in adults, up to a year - lower
The content of blood proteins up to 3 years is lower, and then
- like adults

Age features of the circulatory system

In newborns, the atria have a larger volume than
ventricles
Left and right ventricles are equal
The growth rate of the great vessels is less than that of the heart
The blood vessels of newborns are thin-walled - weakly
muscular and elastic layers are expressed
Heart rate at birth is 140 beats per minute, decreases with age, which
due to cholinergic influence
BP increases with age, the level depends on
emotional, mental and physical state
The development of the innervation apparatus of the heart is completed by 7
years
In adolescence, the regulation of the vascular
tone - youthful dystonia (hypertension, hypotension)
Conditioned and vascular reflexes start well
appear at 7-8 years of age

Age features of the respiratory system

In newborns - low compliance
lung tissues and high compliance of the walls
chest
Breathing is fast and shallow
lung ventilation is worse than in adults
The respiratory center in a child is different
low excitability, lability and
fast exhaustion

Features of digestion in children

In newborns - all the functions of the digestive tract
adapted to milk processing
Relatively low enzymatic activity
low acidity
Pepsin breaks down casein well, poorly - albumins and
globulins
The digestive capacity of gastric juice is determined
chymosin, which is active even in an alkaline environment
The low activity of pancreatic juice is due to low
enterokinase production
In the intestine, parietal digestion predominates
Humoral regulation prevails
Often discoordination of the motor function of the gastrointestinal tract, so it is easy
occur, regurgitation, vomiting, diarrhea

Features of the activity of the nervous system in children

In newborns -
dominant are food and thermoregulatory
centers
from the moment of birth, congenital reactions are well manifested
tactile, proprioceptive, olfactory. taste and
vestibular irritations, weakly expressed - on visual and
auditory
wide afferent and efferent generalization of reflexes
efferent generalization is manifested by involvement in the reaction
a large number of effectors (insertions have not yet matured
inhibitory neurons)
In the 1st week of life, conditional (natural)
reflexes in response to interoceptive stimuli (irritations
vestibular apparatus, skin and proprioceptors)
By the end of the 2nd week, conditional (artificial)
reflexes in response to distant stimuli stimuli (smell,
sound, light and color)
By the age of 5 months, all analyzers reach a level of maturity,
sufficient to develop complex conditioned reflexes
The older the child, the faster they develop
conditioned reflexes with fewer combinations

Age features of the activity of the nervous system in children

An important factor in development is the development of a stereotype (diet,
sleep and wakefulness)
With age, reflex reactions become more localized,
and some disappear
By the end of the 1st year, the WORD is included in the number of conditional signals -
beginning of development of the 2nd signaling system
For the full development of analysis and synthesis, a game
activities involving and motor analyzer:
examining, feeling, naming, etc.
Walking and the development of hand function contribute to a wide
the use of all analyzers and the rapid development of the analytic-synthetic function
The development of fine motor skills is necessary for the development of speech
functions
The cortical part of the visual analyzer matures by 4-7 years
Myelination of nerve fibers is completed by 3-5 years
The brain is richly supplied with blood and permeability
blood-brain barrier is high, so it is easy to experience
toxic forms infectious diseases

Aging is a destructive process, which is opposed by vitaukt - a mechanism for protecting the body from destruction, which arose in the process of evolution.

Aging is a destructive process
which is opposed by the vitaukt -
body's defense mechanism against
destruction that occurred in the process
evolution
natural aging
Premature aging (progeria)
Slow (retarded)
Aging is characterized by:
Heterochronism - difference in time
the onset of aging of various organs and systems
Heterotropy - different rates of aging in
different departments of the same organ

Theories of aging

Genetic theory - there are juvenile genes,
responsible for the program of early ontogenesis, and genes
aging, disrupting the mechanism of DNA repair
Metabolic theory - wear of tissues under the influence of
external factors and decrease in intensity and speed
metabolic processes
Conformational theory - changing the structure of membranes,
its properties, transport of substances and function of cells, as well as
strengthening of intermolecular bonds and decrease
functionality of macromolecules (collagen and
elastin)
Cellular theory - replacement of "noble" tissues
connective, the occurrence of immunodeficiency
states and activation of antibody production
Adaptive-regulatory theory - integration
microdamages arising from each individual act
adaptations in immediate response systems and in systems
ensure
Supraorganismal theory - aging under the influence
adverse environmental factors

Vitaukt - anti-aging mechanisms

Genetically programmed mechanisms -
antioxidant system, DNA repair system,
antihypoxic system
Phenotypic mechanisms - emergence
multinucleated cells, compensatory increase
size and activity of intracellular organelles,
hypertrophy and hyperfunction of some cells in
conditions for the death of some of them, an increase
sensitivity to mediators under conditions
weakening of nervous control
Passive protection mechanism - reduction
adaptive responses to external influences

Factors that reduce the rate of aging of the body

Healthy lifestyle including
age-appropriate motor and
intellectual activity
Balanced diet
Avoidance of bad habits
Ability to relieve stress
Social activity
Hygienic body care
The use of oxygen therapy, tissue
therapy, adaptogens, antioxidants, BAS,
vitamins, trace elements and hormones

slide 1

slide 2

“Our arrival and departure are mysterious - their goals All the sages of the Earth failed to comprehend. Where is the beginning of this circle, where is the end? Where did we come from, where will we go from here? Omar Khayyam

slide 3

What is ontogeny? Ontogeny, or individual development, is the entire period of an individual's life from the moment the spermatozoon fuses with the egg and the formation of a zygote until the end of life. What periods is ontogeny divided into? Ontogeny is divided into two large periods: 1- embryonic - the period from the formation of a zygote to birth; 2 - postembryonic - from birth to the end of life.

slide 4

Brief historical background Academician of the Russian Academy Karl Maksimovich Baer (1792-1876) is considered to be the founder of modern embryology. In 1828, he published The History of the Development of Animals, in which he laid the foundation for the theory of germ layers and formulated the law of germ similarity. What is the name of the science that studies ontogeny? Embryology deals with the study of issues related to the individual development of the organism (from the Greek “embryonic” - embryo).

slide 5

Karl Baer proved that man develops according to a single plan with all vertebrates. Thanks to the works of Alexander Onufrievich Kovalevsky (1840 - 1901) and Ilya Ilyich Mechnikov (1845 - 1916), as well as other scientists of the second half of the 19th century. established the principles of development of invertebrates and vertebrates.

slide 6

At the beginning of the twentieth century. Fritz Müller (1821 - 1897) and Ernst Haeckel (1834 - 1919) formulated the biogenetic law: "The individual development of each individual (ontogeny) is a brief and rapid repetition of the historical development (phylogenesis) of the species." Alexey Nikolaevich Severtsov (1866 - 1936) clarified the wording: "The signs are repeated not of adult ancestors, but of their embryos."

Slide 7

In the embryonic period of development, the body goes through the following stages: zygote - a cell formed as a result of fertilization; blastula - a multicellular single-layer embryo; gastrula - two-layer, then three-layer embryo; neurula - an embryo with a complex of axial organs: neural tube, notochord, intestinal tube.

Slide 8

The period of our life, which we easily discard, naming the day of our birth ... Fertilization and the formation of a zygote occur in the fallopian tube. The blastula, consisting of 30-32 cells, enters the uterus and is introduced into its mucous membrane. The process of gastrula formation goes simultaneously with the formation of the embryonic membranes: amnion and chorion. By the end of the 3rd week, the formation of neurula is completed.

Slide 9

A five-week-old fetus has the rudiments of all organs. He lies snugly in an amniotic sac filled with fluid. Through the umbilical cord, it is connected to the placenta, a flattened organ on the wall of the uterus. Through the placenta, the fetus receives oxygen from the mother's body and nutrients, but gives carbon dioxide and decay products.

slide 10

Second month (6 weeks): the fetus has everything internal organs. His heart is beating, his brain cells are working. Embryo weight - 30 g. Third month (10 weeks): the fetus is fully formed. He can suck his thumb, feels pain.

slide 11

Fifth month (19 weeks). The child actively moves and reacts to sounds. Seventh month (28 weeks). The child is preparing for an independent life. He falls asleep and wakes up with his mother, listening to her voice.

slide 12

POST-EMBRIONAL PERIOD The period begins with the birth of a person and ends with his death. There are the following stages of development: -newborn age; - infancy - up to 12 months; - preschool age- up to 7 years; - adolescence - from 10 to 18 years; -maturity - from 18 to 45 years; - menopause - age 48 - 54 years; Old age is the last period of a person's life.

slide 13

CHILD UNTIL 12 MONTHS The bones of the skull are not fused - they are connected by fontanelles, the spine is without bends. Gradually, the child masters the movements. Milk teeth appear.

slide 14

Adolescence The musculoskeletal system develops intensively. Secondary sexual characteristics develop: pubic and armpit hair grows, boys grow genitals, girls begin menstruation.