Concept and features of humoral regulation (biology 8th grade)

The concept of regulation of functions

The human body is the pinnacle of transformations that took place in the process of evolution. All systems and organs have a complex structure, and nature has provided 2 ways to regulate functions and processes. Their features and essence are studied by biology. At school this topic is taught in the 9th grade. As part of the program, the teacher talks about the characteristics of regulators, gives their classification, and then asks students to make a comparison and fill out a table. Types of regulation:

• Nervous. Control is carried out by the system of the same name using impulses. This is a faster mechanism.
• Humoral. Some followers of pseudo-scientific theories express the opinion that the nervous system also takes part in this type of control of vital processes, but thinking so is a mistake. Humoral regulation in the body is carried out with the help of hormones produced by the endocrine glands. Special substances regulate the activity of the heart and other organs, entering the blood and lymph.

Having studied the definition, types and role of humoral regulation of physiological functions, you can understand how it differs from nervous regulation, which also has its own characteristics. You need to know them in order to distinguish between these two mechanisms. The nervous system is divided into central and peripheral. Fibers are distributed throughout the body and bind it into a single whole. Thanks to this, the brain instantly receives signals about what kind of influence a person is exposed to.

So, if you touch a hot or cold object, a so-called wave of excitation instantly spreads along the nerve fibers, followed by a reaction: the person withdraws his hand. The speed of these processes is critical for survival and adaptation to changing environmental conditions.

Congenital and acquired reflexes are determined by the activity of the nervous system. The first include blinking, sucking, breathing and some others. As the child grows and develops, acquired reactions are formed. All of them are characterized by high speed and occur in response to certain stimuli.

The peculiarity of humoral regulation is that it is based on the activity of the organs that form the endocrine system. In another way they are called glands. Each of them secretes hormones - biologically active substances of organic nature. These are humoral factors (agents) that control physiological processes.

You can understand what the physiology of humoral regulation is using the example of the pituitary gland, a gland located at the base of the brain. This organ produces growth hormone, due to which body size increases until about 20 years of age. If there is a deficiency of the substance, a person grows more slowly, and in severe cases, dwarfism develops.

Description

The concept of humoral regulation in biology is closely related to hormones and the nervous system.

Hormones are biologically active substances, small amounts of which are released into the blood and lymph. Substances circulate through the blood until they reach the desired cells. Hormones are captured by cellular receptors that change the functioning of the cell in accordance with the received signal. Each hormone has specific receptors.

Hormones solve several problems in the body’s functioning:

• stimulate or inhibit cell growth;
• stimulate the immune system or suppress its activity;
• regulate metabolism (metabolism);
• regulate puberty, pregnancy, childbirth, menopause;
• cause sexual desire;
• maintain a constant internal environment (homeostasis);
• control the production of other hormones and the functioning of internal organs.

In the human body and other mammals, humoral is subject to nervous regulation. The interaction of hormones and nerve impulses forms a system of neurohumoral regulation.

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Hormones are quickly destroyed (within an hour), so their constant production is necessary for the normal functioning of the entire body. For the synthesis of hormones, organic and inorganic substances (vitamins, minerals) are needed, which enter the body with food.

The structure and functioning of the glands

In addition to the pituitary gland, there are many other glands in the body that interact with each other. Together they provide biological homeostasis. Thus, the body of a healthy person functions as a self-regulating system, which is characterized by the presence of feedback.

For example, one of the most important indicators that affects the well-being and functioning of internal organs is blood sugar level. It is regulated by two hormones - insulin and glucagon, with the first being an antagonist of the second. One substance is responsible for ensuring that the indicators do not exceed the upper limit, the other does not allow an excessive decrease.

To ensure regulation, it is necessary that hormones are not only produced in the required quantities, but also absorbed by the body . Depending on the type of secretion, all glands are divided into 3 groups:

• external (liver, glands of the stomach, intestines);
• internal (epiphysis, pituitary gland, adrenal glands, thymus, thyroid);
• mixed (kidneys, pancreas, genitals).

Exocrine secretion organs include lacrimal, sebaceous and salivary organs. The glands of this group have excretory ducts through which biologically active substances enter the body cavities or onto the surface of the skin.

The internal (endocrine) secretion organs produce hormones that enter directly into the blood. These glands do not have excretory ducts; the only way to carry out regulation is through fluid media. Lymphatic and blood flow ensure that hormones are distributed evenly throughout the body, reaching every cell. These substances regulate the speed of basic processes, including the following:

• metabolism (metabolism);
• puberty;
• height;
• physical and mental development;
• brain activity;
• functioning of the liver, kidneys, cardiovascular and other systems.

Nervous and humoral regulation

Nervous regulation

carried out using electrical impulses traveling along nerve cells. Compared to humoral it

• happens faster
• more accurate
• requires a lot of energy
• more evolutionarily young.

Humoral regulation

vital processes (from the Latin word humor - “liquid”) are carried out due to substances released into the internal environment of the body (lymph, blood, tissue fluid).

Humoral regulation can be carried out with the help of:

• hormones
  - biologically active (acting in very small concentrations) substances released into the blood by the endocrine glands;
• other substances
  . For example, carbon dioxide causes local expansion of capillaries, more blood flows to this place;
• stimulates the respiratory center of the medulla oblongata, breathing intensifies.

All glands of the body are divided into 3 groups

1) Endocrine glands ( endocrine

) do not have excretory ducts and secrete their secretions directly into the blood.
The secretions of the endocrine glands are called hormones
; they have biological activity (act in microscopic concentration). For example: thyroid gland, pituitary gland, adrenal glands.

2) Exocrine glands have excretory ducts and secrete their secretions NOT into the blood, but into some cavity or onto the surface of the body. For example, liver

,
tearful
,
salivary
,
sweaty
.

3) Mixed secretion glands carry out both internal and external secretion. For example

• the pancreas secretes insulin and glucagon into the blood, and not into the blood (into the duodenum) - pancreatic juice;
• The gonads
  secrete sex hormones into the blood, but not into the blood - germ cells.

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DETAILED SUMMARY: Humoral regulation, Types of glands, Types of hormones, timing and mechanisms of their action, Maintaining blood glucose concentrations

ASSIGNMENTS OF PART 2 OF THE USE ON THIS TOPIC

Part 1 tasks

Choose one, the most correct option. Which of the following glands secrete their products through special ducts into the cavities of the body organs and directly into the blood?

1) sebaceous 2) sweat 3) adrenal glands 4) genitals

Answer

4

NERVOUS - HUMORAL SIGNS 1. Establish a correspondence between the sign of regulation of functions in the human body and its type: 1) nervous, 2) humoral. Write numbers 1 and 2 in the correct order.

A) is delivered to organs by blood B) has a high response rate C) is more ancient D) is carried out with the help of hormones E) is associated with the activity of the endocrine system

Answer

21222

2. Establish a correspondence between the characteristics and types of regulation of body functions: 1) nervous, 2) humoral. Write numbers 1 and 2 in the order corresponding to the letters.

A) turns on slowly and acts for a long time B) the signal spreads along the structures of the reflex arc C) is carried out by the action of a hormone D) the signal spreads with the blood flow E) turns on quickly and acts briefly E) evolutionarily more ancient regulation

Answer

212212

NERVOUS - HUMORAL GLANDS EXAMPLES Establish a correspondence between the organ (organ department) involved in the regulation of the vital functions of the human body and the system to which it belongs: 1) nervous, 2) endocrine.

A) pons B) pituitary gland C) pancreas D) spinal cord E) cerebellum

Answer

12211

NERVOUS - HUMORAL EXAMPLES OF PROCESSES 1. Establish a correspondence between the process that occurs during human breathing and the method of its regulation: 1) humoral, 2) nervous

A) stimulation of nasopharyngeal receptors by dust particles B) slowing of breathing when immersed in cold water C) change in breathing rhythm when there is an excess of carbon dioxide in the room D) disturbance of breathing when coughing E) change in breathing rhythm when the level of carbon dioxide in the blood decreases

Answer

22121

2. Establish a correspondence between the example of regulation of the heart and the type of regulation: 1) humoral, 2) nervous

A) increased heart rate under the influence of adrenaline B) changes in heart function under the influence of potassium ions C) changes in heart rate under the influence of the autonomic system D) weakening of heart activity under the influence of the parasympathetic system

Answer

1122

3. Establish a correspondence between examples and types of breathing regulation in humans: 1) reflex, 2) humoral. Write numbers 1 and 2 in the order corresponding to the letters.

A) stopping breathing on inhalation when entering cold water B) increasing the depth of breathing due to an increase in the concentration of carbon dioxide in the blood C) coughing when food enters the larynx D) slight holding of breath due to a decrease in the concentration of carbon dioxide in the blood E) change breathing intensity depending on the emotional state E) cerebral vascular spasm due to a sharp increase in oxygen concentration in the blood

Answer

121212

HUMORAL 1. Select three options. Humoral effects on physiological processes in the human body

1) are carried out with the help of chemically active substances 2) are associated with the activity of the exocrine glands 3) spread more slowly than nerve impulses 4) occur with the help of nerve impulses 5) are controlled by the medulla oblongata 6) are carried out through the circulatory system

Answer

136

2. Choose three correct answers out of six and write down the numbers under which they are indicated. What is characteristic of the humoral regulation of the human body?

1) the response is clearly localized 2) the signal is a hormone 3) it turns on quickly and acts instantly 4) the signal is transmitted only chemically through body fluids 5) the signal is transmitted through a synapse 6) the response lasts for a long time

Answer

246

HUMORAL PROCESS EXAMPLES Select three options. In what cases is humoral regulation carried out?

1) excess carbon dioxide in the blood 2) the body’s reaction to a green traffic light 3) excess glucose in the blood 4) the body’s reaction to changes in body position in space 5) the release of adrenaline during stress

Answer

135

HUMORAL SEQUENCE Establish the sequence in which the humoral regulation of respiration occurs during muscular work in the human body

1) accumulation of carbon dioxide in tissues and blood 2) excitation of the respiratory center in the medulla oblongata 3) transmission of impulses to the intercostal muscles and diaphragm 4) enhancement of oxidative processes during active muscular work 5) inhalation and air flow into the lungs

Answer

41235

INTERNAL 1. Select three endocrine glands.

1) pituitary gland 2) reproductive glands 3) adrenal glands 4) thyroid glands 5) gastric glands 6) mammary glands

Answer

134

2. Select three options. The endocrine glands include

1) pituitary gland 2) salivary glands 3) adrenal glands 4) sebaceous glands 5) intestinal glands 6) thyroid gland

Answer

136

3. Choose three correct answers out of six and write down the numbers under which they are indicated. Which gland cells secrete secretions directly into the blood?

1) adrenal glands 2) lacrimal glands 3) liver 4) thyroid 5) pituitary gland 6) sweat glands

Answer

145

INTERNAL - EXTERNAL CHARACTERISTICS 1. Establish a correspondence between the characteristics of the gland and the type to which it is classified: 1) internal secretion, 2) external secretion. Write numbers 1 and 2 in the correct order.

A) have excretory ducts B) produce hormones C) provide regulation of all vital functions of the body D) secrete enzymes into the stomach cavity E) excretory ducts exit to the surface of the body E) produced substances are released into the blood

Answer

211221

2. Establish a correspondence between the characteristics of the glands and their type: 1) external secretion, 2) internal secretion. Write numbers 1 and 2 in the correct order.

A) form digestive enzymes B) secrete secretions into the body cavity C) secrete chemically active substances - hormones D) participate in the regulation of vital processes of the body E) have excretory ducts

Answer

11221

INTERNAL - EXTERNAL EXAMPLES 1. Establish a correspondence between glands and their types: 1) external secretion, 2) internal secretion. Write numbers 1 and 2 in the correct order.

A) pineal gland B) pituitary gland C) adrenal gland D) salivary gland E) liver E) pancreatic cells that produce trypsin

Answer

222111

2. Establish a correspondence between the gland in the human body and its type: 1) internal secretion, 2) external secretion

A) mammary gland B) thyroid gland C) liver D) sweat gland E) pituitary gland E) adrenal glands

Answer

212211

INTERNAL - EXTERNAL - MIXED Establish a correspondence between the gland of the human body and the type to which it belongs: 1) internal secretion, 2) mixed secretion, 3) external secretion

A) pancreas B) thyroid C) lacrimal D) sebaceous D) genital E) adrenal gland

Answer

213321

EXTERNAL Choose three correct answers out of six and write down the numbers under which they are indicated. Exocrine glands include

1) pancreas 2) salivary glands 3) thyroid gland 4) adrenal glands 5) sweat glands 6) liver

Answer

256

© D.V. Pozdnyakov, 2009-2020

Violation of secretion processes

When the activity of the endocrine glands is impaired, doctors diagnose hypo- or hyperfunction. In this case, the patient requires treatment. Which organ is not working correctly is determined through a series of examinations.

An example is the pituitary gland. In addition to dwarfism, which occurs as a result of hypofunction, there is another disease caused by the improper functioning of this gland. When the pituitary gland produces more growth hormone than needed, gigantism develops. Like dwarfism, it is a deviation from the norm.

Another example is the thyroid gland, which plays a very important role. Hormones produced by this organ:

• triiodothyronine;
• calcitonin;
• thyroxine.

If in childhood less hormones are produced than needed for normal development, doctors diagnose cretinism. The main symptom of this disease is mental retardation. In adulthood, hypofunction of the thyroid gland can also be observed. The disease is known as hypothyroidism. Signs of pathology:

• increased fatigue;
• drowsiness;
• swelling of the mucous membrane;
• dry skin;
• weight gain;
• decreased hemoglobin levels;
• brittle nails and hair.

The opposite situation is also possible, when more hormones are produced than are needed for the normal functioning of all systems and organs. In this case, the person develops Graves' disease.

It is characterized by the following symptoms:

• headache;
• general malaise;
• fatigue;
• excitability;
• anxiety;
• insomnia;
• tremor (shaking) of the limbs;
• increased sweating;
• erythema;
• lifting of the upper eyelid and drooping of the lower;
• thyroid acropachy;
• sudden weight loss accompanied by excellent appetite;
• high blood pressure;
• conjunctivitis and other phenomena.

Other endocrine secretion glands are the thymus, parathyroid and adrenal glands. The latter secrete two important hormones - adrenaline and norepinephrine. These substances are responsible for the ability to survive in extreme situations. When adrenaline is released into the blood, metabolism accelerates. As a result, the muscles receive the energy necessary to withstand the increased load.

Norepinephrine is a reverse-acting hormone. It protects the body from overload and premature wear. Together, both substances support energy production at normal levels. Problems begin when the balance is disrupted for a long time.

Insulin, glucagon and sex hormones

The reproductive and pancreas are classified as endocrine glands. Each of them produces not one, but 2 types of hormones at once. Glucagon and insulin are synthesized in the pancreas. When a person is healthy, these processes occur unnoticed and without any intervention. But as soon as the regulatory mechanism fails, diabetes develops. The main symptom of the disease is abnormal blood glucose levels. If the disease is mild, it is enough for a person to follow a diet. When insulin-dependent diabetes develops, the patient needs constant medication or insulin injections. This form of the disease also requires special nutrition.

In addition to insulin and glucagon, the pancreas produces a substance that breaks down complex polymers into simple ones. This compound is called digestive juice . Released from the pancreas, the secretion enters the duodenum, where lipids and proteins are broken down into their component parts.

The gonads also secrete hormones - estrogen (female) and testosterone (male). The production of these substances begins while the body is in the embryonic stage. During the period of fetal formation, the function of hormones is to form sexual characteristics.

In addition to estrogen and testosterone, the glands form gametes - reproductive cells that have a single (haploid) set of chromosomes and take part in sexual reproduction.

In men and women, the organs involved in conception have the same structure, but look different. The female reproductive system is represented by the ovaries, their ducts and eggs. In men, it consists of excretory tubules, testes and sperm. The gonads, along with the others, take part in humoral regulation.

All processes in the body are interconnected and proceed as a single whole. Humoral regulation is part of this mechanism. In the process of evolution, it arose earlier than the nervous one. Humoral regulation has a long-term effect, extends to the entire body and is carried out with the participation of endocrine organs.

Basic Concepts

It is believed that body functions are regulated by two systems - nervous and humoral. However, these are not independent regulatory mechanisms. There is a strong connection between them, thanks to which the body functions as a single complex system.

The mechanism of humoral regulation of body functions (from the Latin word humor - liquid) implies the ability of certain substances circulating in the bloodstream to influence organs and systems: change them, “turn them on” and “turn them off”. Depending on the changing conditions of the external and internal environment, the reaction of cells to such regulatory influences may be different:

1. Increased growth. Thus, tissues respond, for example, to the active production of somatotropic hormone (“growth hormone”).
2. Reduction. This reaction is characteristic of muscle cells. Adrenaline, in particular, can enhance contractile function.
3. Division. An example of the activation of the process of cell division is the processes that start in the body upon fertilization of the egg. Changes in hormonal levels cause intense division (meiosis). As a result, there is a fairly rapid increase in the mass of the group of cells that form the embryo.

The tissue response to the effects of biologically active compounds (mediators of humoral regulation) depends on the specialization of the cells that are affected by a particular substance.

To help in mastering the topic of humoral regulation of body functions, the school textbook on biology presents a comparison of hormones and enzymes. To better assimilate the material, students are recommended to create and fill out a table in which they briefly indicate the actions of each of the biologically active compounds. This form of presentation, due to its clarity, promotes better memorization and helps to better navigate the topic material.