The nervous and endocrine systems are the main regulatory systems of the human body. Regulatory systems of the human body

Body regulation mechanisms
humoral regulation
(endocrine system)
carried out with the help of BAV,
secreted by cells
endocrine system into liquid
media (blood, lymph)
nervous regulation
(nervous system)
carried out through
electrical impulses
walking along the nerve
cells
Homeostasis - the constancy of the internal environment

Endocrine
system

Classification of glands of the endocrine system
internal
secretions
release hormones,
do not have output
ducts,
hormones enter
blood and lymph
external
secretions
mixed
secretions
reveal secrets,
have output
ducts,
secrets come to
body surface or
hollow organs
duct
cells
glands
circulatory
vessel

Hormones
biologically active substances,
providing regulatory
influence on bodily functions

General properties of hormones
specificity,
high biological activity,
remote Action,
generalized action,
prolongation of action

glands
internal secretion

Pituitary
located on the lower surface of the brain
oval shape ≈1cm

Pituitary
thyrotropin TSH
stimulates work
thyroid gland
adrenocorticotropin
ACTH
stimulates work
adrenal glands
growth hormone GH
stimulates growth
melanotropin MTG
stimulates cells
skin affecting
her color
vasopressin
(antidiuretic) ADH
gonadotropin htg
keeps water in
kidneys, regulates blood pressure
regulates the work
genitals

epiphysis
(pineal body)
located
in the center of the brain
oval shape ≈1cm
After 7 years of iron
partially atrophies

epiphysis
melatonin
regulates cyclic
processes in the body
(change of day and night: during daylight hours
melatonin synthesis is inhibited,
and in the dark - stimulated)
inhibits growth and
puberty

Thyroid
located in front and
on the sides below the larynx
larynx
thyroid
gland
trachea
The activity of the gland is increased
in middle and high school
age due to sex
ripening

thyroxine (T4)
increase
metabolic rate
substances and
heat generation,
stimulate growth
skeleton,
Thyroid
gland
triiodothyronine (T3)
calcitonin
increase
excitability of the central nervous system
enhances deposition
calcium in bone tissue

parathyroid glands
Located on the back
thyroid gland
have a rounded shape ≈0.5 cm
thyroid
gland
parathyroid
glands

parathyroid glands
parathormone
regulates the level
calcium and phosphorus

thymus
(thymus)
thymus
Located behind the handle of the sternum
Ribs
Lungs
Sternum
Heart
Increases rapidly in the first 2 years of life
reaches its greatest value at the age of 11-15 years.
From the age of 25, a gradual decrease begins
glandular tissue with replacement of its fatty
fiber.

The thymus is made up of two lobes
Is the central authority
immunity:
it reproduces immune
cells - lymphocytes

thymus
thymosin
affects:
carbohydrate metabolism,
exchange of calcium and phosphorus,
regulates skeletal growth

adrenal glands
Located in the retroperitoneum
above the upper pole of the corresponding
kidneys.
L ≈ 2-7 cm, W ≈ 2-4 cm,
T ≈ 0.5-1 cm
Right adrenal gland
triangular,
left - lunate

Mineralocorticoids:
aldosterone
Cortical layer
Medulla
Glucocorticoids:
hydrocortisone
cortisol
affect the water-salt
exchange
regulate carbohydrate,
protein and fat metabolism
Sex steroids:
androgens,
estrogens
similar to hormones
gonads
adrenalin,
norepinephrine
increase heart rate, respiratory rate, blood pressure

Pancreas
D 15-20 cm
W 6-9 cm
Located behind the stomach

Pancreas
external secretion
pancreatic juice
glands
Enters the duct of the gland
internal secretion
Glucagon
Enter the blood
in the 12-point gut
involved in digestion
Insulin
raises
content
blood glucose
reduces
content
glucose in
blood

sex glands
glands
Sexual
Men's
Women's

ovaries
external secretion
internal secretion
Hormones
Egg production
Estrogens
Progesterone
Enter the blood
Influence at
development
secondary
genital
signs
hormone
pregnancy

testicles
external secretion
Sperm production
internal secretion
Hormones
Androgens
(testosterone)
Enter the blood
impact on development
secondary sexual characteristics

Nervous system

Functions of the nervous system
1. Regulatory
(provides consistent
organs and systems).
work
2. Carries out the adaptation of the body
(interaction with the environment).
3. Forms the basis of mental
activities
(speech, thinking, social behavior).
all

The structure of the nervous tissue
nervous tissue
Neuron
neuroglia
nerve cell
supporting cells
structural and
functional
NS unit
support, protection and
nutrition of neurons

Functions of a neuron
perception (receiving),
holding,
processing (transfer) of information

Classification of the nervous system (topographic)
CNS
Brain
peripheral
Nerve fibers
Spinal cord
nerve nodes
Nerve endings

Classification of the nervous system (functional)
Somatic
regulates the work
skeletal muscles, tongue, larynx,
throat and skin sensitivity
Regulated by the cerebral cortex
Vegetative
sympathetic
Parasympathetic
regulate metabolism,
work internal organs,
blood vessels, glands
Not regulated by the cerebral cortex
brain
maintain homeostasis

Central NS

Spinal cord
spinal canal
vertebra
spinal cord
spinal
roots
Is in
spinal canal
in the form of a burden
at its center -
spinal canal.
Length=43-45cm

Spinal cord
composed of gray and white matter
gray matter collection of bodies
neurons in the center
spinal cord
(in the form of a butterfly)
white matter -
educated
nerve fibers,
surrounds the gray

Spinal Cord Functions
reflex
- is carried out due to the presence
reflex centers
body muscles and
limbs.
With their participation,
tendon reflexes,
flexion reflexes, reflexes
urination, defecation,
erections, ejaculations, etc.
conductive
- carried out by conductive
ways
They carry a nerve impulse
to the brain and back.
The activity of the spinal cord is subordinate to the brain

Brain
located in the skull
Brain
Average weight:
adult (by 25) - 1360 g,
newborn - 400 g

The structure of the brain
Gray matter
white matter
accumulation of bodies of neurons
processes of neurons
Nuclei
Bark
- reflex
- outer layer
big
hemispheres (4mm)
centers
reflex
function
are
ascending and descending
nerve fibers
(conducting paths),
connecting departments of GM and SM
conductive function

Sections of the brain
rear
average
oblong
brain
quadrigemina
intermediate
thalamus
hypothalamus
cerebellum
bridge
brain stem
finite
large
hemisphere

Brain
contemporary
mammals -
bark
consciousness,
intelligence,
logics
2 Ma
Brain
ancient
mammals -
subcortex
the senses,
emotions
(thalamus, hypothalamus)
Brain
reptiles -
brain stem
100 Ma
instincts,
survival

Age features of brain development
CNS structures mature non-simultaneously and asynchronously
Sections of the brain
Development Completion Period
Subcortical structures
mature in utero and complete
development during the first year
life
Cortical structures
12-15 years old
Right hemisphere
5 years
Left hemisphere
8-12 years old

General principles of regulation of the vital activity of the organism

Throughout its development, the organism is continuously updated, retaining some of its properties and changing or losing others. However, there are basic properties, although partially changing, but constantly allowing it to maintain its existence and adequately adapt to changing environmental conditions. There are only three of them:

metabolism and energy,

Irritability,

regulation and self-regulation.

Each of these properties can be traced at the cellular, tissue and system levels, but at each of these levels they have their own characteristics.

The human body is a set of hierarchically connected (not only interconnected, but also interdependent, mutually subordinate) systems, but at the same time it is a single complex multi-element system. The interconnected and normal vital activity of all the constituent parts (organs and systems) of the body is possible only under the indispensable condition of maintaining the relative physico-chemical constancy of its internal environment. This constancy is dynamic in nature, since it is maintained not at an absolutely constant level, but within the limits of permissible fluctuations of the basic physiological functions. It's called homeostasis.

Homeostasis is possible due to the mechanisms of regulation and self-regulation. Regulation - is the implementation of the reactions of the body and its systems, ensuring the adequacy flow of vital functions and activities of various environmental characteristics(physical, chemical, informational, semantic, etc.). Regulation performs the function of integration human body as a whole.

Regulation of organ functions - this is a change in the intensity of their work to achieve a useful result according to the needs of the body in various conditions his life activity.

Changing the parameters of functions while maintaining them within the boundaries of homeostasis occurs at each level of the body or in any hierarchical system due to self-regulation, or domestic for the system life control mechanisms. Local mechanisms of self-regulation inherent in organs and systems can be observed in the examples of the work of the heart, stomach, intestines or the automatism of alternating inhalation and exhalation in the respiratory system. For the implementation of the functions of the body as a whole, the interconnection and interdependence of the functions of its constituent systems is necessary. In this sense, the organism can be considered as a self-organizing and self-regulating system, and self-regulation as a property of the whole organism.

The activity of the organism as a whole is carried out due to the regulation of the nervous and humoral systems. These two systems are interconnected and mutually influence each other.

The regulation of functions in the human body is based on the impact on the physiological system, organ or set of organs through control signals received in the form nerve impulses or directly humoral (chemical) factor. When analyzing the mechanisms of regulation, as a rule, the reflex and humoral components are considered separately.

Humoral (chemical) regulators can be some compounds that enter the body with food (for example, vitamins), a product of the vital activity of cells formed during metabolism (for example, carbon dioxide), physiologically active substances synthesized in tissues and organs (prostaglandins, kinins and etc.), prohormones and hormones of the diffuse endocrine system and endocrine glands. These chemical substances enter the tissue fluid, then into the blood, are carried throughout the body and affect cells, tissues and organs distant from the cells where they are formed. Hormones are the most important specialized chemical regulators. They can cause the activity of organs (triggering effect), enhance or suppress functions (corrective effect), accelerate or slow down metabolic processes and affect the growth and development of the body.

The nervous mechanism of regulation has a higher speed of action compared to the humoral one. Unlike humoral nerve signals are sent to strictly defined organs. All cells, tissues and organs are regulated by the nervous system, which unites and adapts their activity to changing environmental conditions. The basis of nervous regulation are unconditioned and conditioned reflexes.

Both mechanisms of regulation are interrelated, it is difficult to distinguish between them, since they represent different aspects of a single neurohumoral regulation. There are many biologically active substances that can affect the vital activity of nerve cells and the functions of the nervous system. On the other hand, the synthesis and release of humoral factors into the blood are regulated nervous system. In the modern sense, neurohumoral regulation is the regulatory and coordinating influence of the nervous system and biologically active substances contained in the blood, lymph and tissue fluid on the vital processes of the body.

Neurohumoral regulation of body functions- this is the regulation of the activity of the body, carried out by the nervous and humoral systems. The leading role belongs to the nervous system (more rapid response of the organism to changes in the external environment).

Regulation is carried out according to the principles: 1) self-regulation- the body, with the help of its own mechanisms, changes the intensity of the functioning of organs and systems according to its needs in various conditions of life. Ex: when running, the activity of the central nervous system, muscle, respiratory and cardiovascular systems, and at rest their activity is significantly reduced. 2) systemic principle – functional systems according to P.K. Anokhin.

The meaning and general plan of the structure of the nervous system. The main regularities of the ontogeny of the nervous system.

Function of the nervous system: regulates the activity of all organs and systems, causing their unity, connection with the external environment with the help of highly differentiated cells that perceive and transmit information.

According to the topographic principle, the nervous system is divided into central ( spinal cord, brain) and peripheral(somatic and autonomic) - represented by fibers and nerves of 12 pairs of cranial and 31 pairs of spinal cords. The somatic system innervates the work of skeletal muscles, the autonomic (autonomous) nervous system, in turn, is divided into sympathetic and parasympathetic and innervates the work of internal organs.

The nervous system regulates: 1) the behavior of the organism in the external environment. This regulation by I.P. Pavlov called GNI; 2) regulates the work of internal organs - lower nervous activity.

The central nervous system (CNS) plays a leading role in the organization of adaptive processes occurring during individual development. Therefore, the dynamics of morpho-functional transformations in this system is downloaded on the nature of the activity of all body systems.

The number of CNS neurons reaches its maximum number in the 24-week-old fetus and remains constant until old age. Differentiated neurons are no longer capable of dividing, and the constancy of their numbers plays a major role in the accumulation and storage of information. Glial cells continue to remain immature even after birth, which leads to a deficiency in their protective and supporting functions for brain tissue, slow metabolic processes in the brain, its low electrical activity, and high permeability of the blood-brain barrier.

By the time of birth, the fetal brain is characterized by low sensitivity to hypoxia, low level metabolic processes (metabolism) and the predominance during this period of the anaerobic mechanism for obtaining energy. Due to the slow synthesis of inhibitory mediators in the CNS of the fetus and newborn, generalized excitation easily occurs even with a small amount of stimulation. As the brain matures, the activity of inhibitory processes increases. In the early stages prenatal development nervous control of functions is carried out mainly by the spinal cord. At the beginning of the fetal period (eighth to tenth weeks of development), control of the medulla oblongata over the spinal cord appears. From 13-14 weeks there are signs of mesencephalic control of the underlying parts of the central nervous system. The corrective effects of the cortex on other structures of the CNS, the mechanisms necessary for survival after birth, are revealed at the end of the fetal period. By this time, the main types are determined unconditioned reflexes: indicative, protective (avoidance), grasping and food. The latter, in the form of sucking and swallowing movements, is most pronounced.

The development of the central nervous system of the child is greatly facilitated by thyroid hormones. A decrease in the production of thyroid hormones in the fetal or early postnatal periods leads to cretinism due to a decrease in the number and size of neurons and their processes, impaired protein and nucleic acid metabolism in the brain, and excitation transmission in synapses.

In comparison with adults, children have a higher excitability of nerve cells, less specialization of nerve centers. AT early childhood many nerve fibers do not yet have a myelin sheath that provides isolated conduction of nerve impulses. As a result, the excitation process easily passes from one fiber to another, neighboring one. Myelination of most nerve fibers in most children ends by the age of three, but in some it continues up to 5-7 years. The high irradiation of nervous processes is largely associated with poor "isolation" of nerve fibers, and this entails imperfect coordination of reflex reactions, an abundance of unnecessary movements and uneconomical vegetative support. Myelination processes normally proceed under the influence of thyroid and steroid hormones. With the development, "maturation" of neurons and interneuronal connections, the coordination of nervous processes improves and reaches perfection by the age of 18-20.

Age-related changes in the functions of the central nervous system are also due to other morphological features of development. Despite the fact that the spinal cord of the newborn is the most mature part of the CNS, its final development is completed simultaneously with the cessation of growth. During this time, its mass increases by 8 times.

The main parts of the brain stand out already by the third month of the embryonic period, and by the fifth month of embryogenesis, the main furrows of the cerebral hemispheres have time to form. The human brain develops most intensively in the first 2 years after birth. Then the rate of its development decreases slightly, but remains high until the age of 6-7, when the child's brain mass reaches 80% of the adult brain mass.

The brain develops heterochronously. The fastest maturation of the stem, subcortical and cortical structures that regulate the vegetative functions of the body. These departments, in their development, already at 2-4 years old are similar to the brain of an adult. The final formation of the stem part and the diencephalon is completed only at the age of 13-16. The paired activity of the cerebral hemispheres in ontogenesis changes from unstable symmetry to unstable asymmetry and, finally, to stable functional asymmetry. Cell structure, the shape and placement of the sulci and convolutions of the projection zones of the cortex become similar to the adult brain by the age of 7. In the frontal regions, this is achieved only by the age of 12. The maturation of the cerebral hemispheres is fully completed only by the age of 20-22.

At the age of 40, the processes of degeneration in the central nervous system begin. Possible demyelination in the posterior roots and pathways of the spinal cord. With age, the rate of propagation of excitation along the nerves decreases, synaptic conduction slows down, and the lability of nerve cells decreases. The inhibitory processes at different levels of the nervous system are weakened. Uneven, multidirectional changes in the individual nuclei of the hypothalamus lead to a violation of the coordination of its functions, changes in the nature of vegetative reflexes and, therefore, to a decrease in the reliability of homeostatic regulation. In older people, the reactivity of the nervous system decreases, the ability of the body to adapt to stress is limited, although in some individuals even at the age of 80 the functional state of the central nervous system and the level of adaptation processes can remain the same as in middle adulthood. Against the background of general changes in the autonomic nervous system, the weakening of parasympathetic influences is most noticeable.

The central nervous system is the most stable, intensively functioning and long-lived system of the body. Its functional activity is ensured by long-term preservation in nerve cells nucleic acids, optimal blood flow in the vessels of the brain and sufficient oxygenation of the blood. However, if these conditions are violated functionality CNS is sharply reduced.

In a multicellular organism, there is a single neuro-endocrine system that ensures the coordinated regulation of functions, structures and metabolism in various organs and tissues.

The nervous system, as a rule, through a chemical synapse (with the help of mediators), affects the cell closest to the nerve ending, and endocrine formations produce hormones that act on many organs and tissues, even remote from their place of production.

The nervous and endocrine systems regulate each other's activity. In addition, the same biologically active substances (BAS) can be secreted by endocrine glands and neurons (for example, norepinephrine).

Even one section of the nervous system (for example, the hypothalamus) is able to influence other structures, both through nerve pathways and with the help of hormones.

General physiology of the endocrine system

The existence of the endocrine system is impossible without secretory cells. They produce their biologically active secrets (hormones), which enter the internal extracellular environments of the body (tissue fluid, lymph and blood). Therefore, the endocrine glands are often called endocrine glands.

The endocrine system includes (Fig. 1) endocrine glands(organs in which most cells secrete hormones), neurohemal formations(neurons that secrete substances that have the properties of hormones) and diffuse endocrine system(cells secreting hormones in organs and tissues, consisting mainly of "non-endocrine" structures).

Rice. 1. The main representatives of the endocrine system: a) endocrine glands (for example, the adrenal gland); b) neurohemal formations and c) diffuse endocrine system (on the example of the pancreas).

Endocrine glands include: pituitary gland, thyroid and parathyroid glands, adrenal gland and pineal gland. An example of a neurohemal structure is oxytocin-secreting neurons, and a diffuse endocrine system is most characteristic of the pancreas, digestive tract, gonads, thymus, and kidneys.

Endocrine glands constantly secrete hormones ( basal level of secretion), and the level of such secretion, as a rule, depends on the rate of their synthesis ( only the thyroid gland accumulates significant amounts of hormones in the form of a colloid).

Thus, in accordance with the classical model of the endocrine system, the hormone is secreted by the endocrine glands into the blood, circulates with it throughout the body and interacts with target cells, regardless of the degree of their removal from the source of secretion.

Hormones Properties and classifications of hormones

Hormones are organic compounds produced in the blood by specialized cells and affecting certain functions of the body outside the place of their formation.

Hormones are: specificity and high biological activity, remoteness of action, ability to pass through the capillary endothelium and rapid renewal.

Specificity appears place of education and selective action hormones to cells. Biological activity hormones is characterized by the sensitivity of the target to very low concentrations (10 -6 -10 -21 M). Distance of action It consists in the manifestation of the effects of hormones at a considerable distance from the place of their formation (endocrine action). Ability to pass through the capillary endothelium facilitates the secretion of hormones into the blood and their transition to target cells, and fast update due to the high rate of hormone inactivation or excretion from the body.

By chemical nature hormones divided into protein, steroid, as well as derivatives of amino acids and fatty acids.

Protein hormones are further divided into polypeptides and proteids (proteins). To steroid include hormones of the adrenal cortex and gonads. Amino acid derivatives tyrosine are catecholamines (epinephrine, norepinephrine and dopamine) and thyroid hormones, and fatty acids prostaglandins, thromboxanes and leukotrienes.

All non-protein and some non-protein hormones also there is no species specificity.

The effects caused by hormones are divided (Fig. 2) into metabolic, morphogenetic, kinetic and corrective(for example, adrenaline increases heart contractions, but even without it, the heart contracts).

effects

Metabolic

Morphogenetic

Kinetic

Corrective

Change the rate of metabolism

Regulate differentiation and metamorphosis of tissues

Increase the activity of target cells

Affect structures that can work in the absence of hormones

Rice. 2. Main physiological effects of hormones.

Hormones are transported by the blood in dissolved and bound (with proteins) states. Bound hormones are inactive and not destroyed. Therefore, plasma proteins provide the functions of transport and depot of the hormone in the blood. Some of them (for example, albumins) interact with many hormones, but there are also specific carriers. For example, corticosteroids preferentially bind to transcortin.

The regulation of many processes in the body is provided by the feedback principle. It was first formulated by the domestic scientist M.M. Zavadovsky in 1933. Feedback means the influence of the result of the system's activity on its activity.

There are "long", "short" and "ultra-short" (Fig. 3) feedback levels.

Rice. 3. Feedback levels.

A long level of regulation ensures the interaction of distant cells, a short level provides interaction in neighboring tissues, and an ultrashort level provides only within one structural formation.

Year of issue: 2003

Genre: Biology

Format: DjVu

Quality: Scanned pages

Description: For recent years characterized by a significant increase in interest in psychology and related sciences. The result of this is the organization a large number universities and faculties that train professional psychologists, including in such specific areas as psychotherapy, pedagogical psychology, clinical psychology, etc. All this creates the prerequisites for the development of textbooks and teaching aids of a new generation, taking into account modern scientific achievements and concepts.
AT study guide « Regulatory systems of the human body” considers natural-science (primarily anatomical and physiological) facts that are relevant to psychological disciplines. It is a holistic course in which data on the higher functions of the brain are presented on the basis of neuromorphological, neurocytological, biochemical and molecular biological concepts. Much attention is paid to information about the mechanisms of action of psychotropic drugs, as well as the origin of the main disorders of the nervous system.
The authors hope that the book "Regulatory Systems of the Human Body" will help students obtain reliable basic knowledge across a range of training courses devoted to the anatomy and physiology of the nervous system, the physiology of higher nervous activity (behavior), the physiology of the endocrine system.

"Regulatory systems of the human body"

BASICS OF THE CELL STRUCTURE OF LIVING ORGANISMS

1. cell theory
2. Chemical organization of the cell
3. Cell structure
4. Synthesis of proteins in the cell
5. Tissues: structure and functions

STRUCTURE OF THE NERVOUS SYSTEM

1. The reflex principle of the brain
2. Embryonic development of the nervous system
3. General idea of ​​the structure of the nervous system
4. Shells and cavities of the central nervous system
5. Spinal cord
6. General structure of the brain
7. Medulla
8. Cerebellum
9. midbrain
10. diencephalon
11. telencephalon
12. Pathways of the brain and spinal cord
13. Localization of functions in the cerebral cortex
14. cranial nerves
15. spinal nerves
16. Autonomic (vegetative) nervous system

GENERAL PHYSIOLOGY OF THE NERVOUS SYSTEM

1. Synaptic contacts of nerve cells
2. Resting potential of a nerve cell
3. The action potential of a nerve cell
4. postsynaptic potentials. Propagation of an action potential along a neuron
5. Life cycle of nervous system mediators
6. Acetylcholine
7. Norepinephrine
8. Dopamine
9. Serotonin
10. Glutamic acid (glutamate)
11. Gamma aminobutyric acid
12. Other non-peptide mediators: histamine, aspartic acid, glycine, purines
13. Mediators-peptides

PHYSIOLOGY OF HIGHER NERVOUS ACTIVITY

1. General ideas about the principles of organization of behavior. Computer analogy of the central nervous system
2. The emergence of the doctrine of higher nervous activity. Basic concepts of the physiology of higher nervous activity
3. Variety of unconditioned reflexes
4. Variety of conditioned reflexes
5. non-associative learning. Mechanisms of short-term and long-term memory
6. Unconditional and conditional inhibition
7. Sleep and wake system
8. Types of higher nervous activity (temperaments)
9. Complex types of associative learning in animals
10. Features of the higher nervous activity of man. Second signal system
11. Ontogeny of human higher nervous activity
12. The system of needs, motivations, emotions

ENDOCRINE REGULATION OF PHYSIOLOGICAL FUNCTIONS

1. General characteristics of the endocrine system
2. Hypothalamic-pituitary system
3. Thyroid
4. parathyroid glands
5. adrenal glands
6. Pancreas
7. Endocrinology of reproduction
8. Pineal gland or pineal gland
9. thymus
10. Prostaglandins
11. Regulatory peptides

INTRODUCTION

I. GLANDS OF INTERNAL AND MIXED SECRETION

II. ENDOCRINE SYSTEM

Functions of the endocrine system

glandular endocrine system

Diffuse endocrine system

Composition of the diffuse endocrine system

Gastrointestinal tract

Atria of the heart

Nervous system

Thymus gland (thymus)

Other hormone-producing tissues and scattered endocrine cells

Regulation of the endocrine system

III. HORMONES

Important human hormones

IV. THE ROLE OF HORMONES IN METABOLISM, GROWTH AND DEVELOPMENT OF THE BODY

Thyroid

parathyroid glands

Pancreas

Diseases of the pancreas

The pancreatic hormone insulin and diabetes mellitus

adrenal glands

ovaries

CONCLUSION

LITERATURE AND INTERNET SOURCES

INTRODUCTION

In the human body, there are external secretion glands that secrete their products into the ducts or out, endocrine glands that secrete hormones directly into the blood, and mixed secretion glands: some of their cells secrete secrets into the ducts or out, the other part secretes hormones directly into the blood. The endocrine system includes glands of internal and mixed secretion that secrete hormones - biological regulators. They act in negligible doses on cells, tissues and organs that are sensitive to them. At the end of their action, hormones are destroyed, allowing other hormones to act. Endocrine glands in different age periods act with different intensity. The growth and development of the body is precisely ensured by the work of a number of endocrine glands. Those. the totality of these glands is a kind of regulatory system of the human body.

In my work, I intend to consider the following questions:

What specific glands of internal and mixed secretion regulate the vital activity of the body?

What hormones are produced by these glands?

· What is the regulatory effect and how does this or that gland, this or that hormone?

I. GLANDS OF INTERNAL AND MIXED SECRETION

We know that in the human body there are such (sweat and salivary) glands that bring their products - secrets into the cavity of any organ or out. They are classified as endocrine glands. External secretion glands, in addition to salivary glands, include gastric, liver, sweat, sebaceous and other glands.

The endocrine glands (see Fig. 1), unlike the external secretion glands, do not have ducts. Their secrets go straight into the blood. They contain substances-regulators - hormones with great biological activity. Even with their negligible concentration in the blood, certain target organs can be turned on or off from work, the activity of these organs can be strengthened or weakened. Having completed its task, the hormone is destroyed, and the kidneys remove it from the body. An organ deprived of hormonal regulation cannot function normally. The endocrine glands function throughout a person's life, but their activity in different age periods is not the same.

The endocrine glands include the pituitary, pineal, thyroid, and adrenal glands.

There are also glands of mixed secretion. Some of their cells secrete hormones directly into the blood, the other part - into the ducts or outward substances characteristic of the external secretion glands.

Glands of internal and mixed secretion belong to the endocrine system.

II. ENDOCRINE SYSTEM

Endocrine system- a system for regulating the activity of internal organs by means of hormones secreted by endocrine cells directly into the blood, or diffusing through the intercellular space into neighboring cells.

The endocrine system is divided into the glandular endocrine system (or glandular apparatus), in which the endocrine cells are brought together to form the endocrine gland, and the diffuse endocrine system. The endocrine gland produces glandular hormones, which include all steroid hormones, thyroid hormones, and many peptide hormones. The diffuse endocrine system is represented by endocrine cells scattered throughout the body that produce hormones called aglandular - (with the exception of calcitriol) peptides. Almost every tissue in the body contains endocrine cells.

Functions of the endocrine system

• It takes part in the humoral (chemical) regulation of body functions and coordinates the activity of all organs and systems.
• It ensures the preservation of the body's homeostasis under changing environmental conditions.
• Together with the nervous and immune systems, it regulates
• growth,
• body development,
• its sexual differentiation and reproductive function;
• takes part in the processes of formation, use and conservation of energy.
• Together with the nervous system, hormones are involved in providing
• emotional reactions
• mental activity of a person

glandular endocrine system

The glandular endocrine system is represented by separate glands with concentrated endocrine cells. The endocrine glands include:

• Thyroid
• parathyroid glands
• thymus or thymus gland
• Pancreas
• adrenal glands
• sex glands:
• Ovary
• Testicle

(for more details on the structure and functions of these glands, see below "ROLE OF HORMONES IN METABOLISM, GROWTH AND DEVELOPMENT OF THE ORGANISM")

Diffuse endocrine system- a department of the endocrine system, represented by endocrine cells scattered in various organs that produce aglandular hormones (peptides, with the exception of calcitriol).

In a diffuse endocrine system, endocrine cells are not concentrated, but scattered. The hypothalamus and pituitary gland have secretory cells, with the hypothalamus considered to be an element of the important "hypothalamic-pituitary system". The pineal gland also belongs to the diffuse endocrine system. Some endocrine functions are performed by the liver (secretion of somatomedin, insulin-like growth factors, etc.), kidneys (secretion of erythropoietin, medullins, etc.), stomach (secretion of gastrin), intestines (secretion of vasoactive intestinal peptide, etc.), spleen (secretion of splenins) and others. Endocrine cells are found throughout the human body.