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What are the components of the endocrine system: Illustrations of Anatomy, Function, Glands $ Organs

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The Endocrine System: A Profile of Glands That Regulate the Body

The endocrine system comprises a number of glands that produce hormones with a varied array of vital functions. Hormones are chemical substances that are secreted by organs or by cells of organs in one part of the body and are carried by the bloodstream to other organs or tissues, where they control or regulate the development or function of those structures.

Endocrine glands are also called ductless glands, because they secrete hormones directly into the bloodstream. In contrast, exocrine glands release their secretions through ducts (for example, the sweat glands produce fluid that flows to the skin’s surface through tiny tubelike sweat ducts).

Hormones can be considered chemical messengers. They are targeted at specific cells in the body, and their arrival in those cells causes specific activities to occur.

One of the major tasks of hormones is to coordinate the activities of organ systems. For example, when a person has to run, the hormone epinephrine acts on the heart to increase its rate and force of contraction; it acts on the blood vessels to increase blood flow to the muscles and decrease blood flow to the gastrointestinal tract. Hormones also help control the type and rate of body growth and metabolism, and they help the body maintain a consistent internal environment.

The endocrine system has a large influence on the way we feel and act. In turn, our energy and other needs in any given situation set the activity of the endocrine system. This feedback relationship is crucial in maintaining our general well-being.

Components of the Endocrine System

The endocrine system consists of glands that release vital hormones into the blood. Let’s review the major types of glands or parts that make up this system.

Adrenal Glands

The adrenal glands are critical to normal body functions, such as maintenance of fluid balance, reaction to stress, and reproduction. There are two adrenal glands, each of which lies above a kidney. The adrenal glands have two distinct parts: the cortex (outer layer), which secretes steroid hormones, and the medulla (inner part), which secretes epinephrine and norepinephrine.

There are more than 30 steroid hormones produced by the adrenal glands. These hormones serve to regulate a wide array of processes throughout the body. Epinephrine and norepinephrine are responsible for the changes in heart rate, blood pressure, and level of usable glucose (a form of sugar) that are necessary to cope with stress.

Pancreas

The pancreas is located in the rear center of the abdominal cavity, behind the stomach. Specialized cells in the pancreas produce two hormones, insulin and glucagon, needed to maintain stable blood sugar levels in the body. Insulin helps body cells use glucose for energy, thereby reducing the amount of sugar in the bloodstream. To balance this action, the hormone glucagon stimulates the liver to release its stored sugar into the blood, thereby raising the blood sugar levels.

The pancreas also functions in digestion. Nonendocrine cells in the pancreas produce special chemicals called enzymes, which are secreted directly into the small intestine through ducts. These enzymes help break down proteins, carbohydrates (sugars and starches), and fats in the small intestine. This dual activity of the pancreas means that it functions as both an endocrine and an exocrine organ.

Pituitary Gland

The pituitary gland is a small organ located just beneath the base of the brain, between the two frontal lobes and directly above a cavity called the sphenoid sinus. It is sometimes called the master gland because all other endocrine glands come under its control. Its job is to receive messages about the need for a particular hormone and to secrete either the hormone or substances that cause the manufacture and release of the hormone.

The anterior (front) lobe of the pituitary gland secretes somatotropin (growth hormone), which affects the body’s general growth; thyrotropic hormone (thyroid-stimulating hormone), which acts on the thyroid gland to stimulate production of thyroid hormones; adrenocorticotropic hormone (ACTH), which stimulates the adrenal cortex; follicle-stimulating hormone and luteinizing hormone, which are necessary for maturation and release of egg and sperm cells; and prolactin, a hormone that acts on the mammary glands to promote the secretion of milk.

The posterior lobe of the pituitary gland secretes oxytocin, which stimulates smooth muscle tissue to contract (and is of critical importance during childbirth) and vasopressin, a hormone that regulates by acting on the kidneys.

Sex Glands

The primary responsibility for hormone production for the reproductive system lies with the testes (male sex glands) and ovaries (female sex glands).

The testes are two oval organs in the scrotum (the pouch of skin behind the penis). The testes produce sperm and sex hormones that govern the male secondary sex characteristics, including the growth of facial hair.

The two ovaries are located in the pelvis. The ovaries secrete the hormones estrogen and progesterone, which govern ovulation (monthly release of an egg from an ovary) and the female secondary sex characteristics, such as breast development.

Thyroid and Parathyroid Glands

The thyroid gland is located at the front of the neck above the top of the breastbone. It consists of two main lobes on either side of the trachea (windpipe) that are connected by a narrow band of tissue called the isthmus. The hormones secreted by the thyroid influence the rate of metabolism (the chemical processes in the body having to do with energy production).

The four parathyroid glands are located on the back and side of each lobe of the thyroid gland. Their secretion, parathyroid hormone, controls calcium levels in the blood.

The endocrine system is one of the most important processes of the body. Understanding the system’s components can help you understand how the human body works.

Diseases of the Endocrine System

Hormone levels that are too high or too low in the endocrine system can cause diseases. One of the most common is diabetes. Diabetes occurs when the pancreas doesn’t produce enough of the hormone insulin or else it can’t use insulin properly. Insulin is what carries sugar from the bloodstream into cells. Another common disease is hypothyroidism, which happens when the thyroid gland is overactive. Many hormone imbalances can affect the reproductive system, like Polycystic ovary syndrome, which results from an overproduction of androgens and often causes infertility. Other endocrine-related diseases include Graves’ disease, Cushing’s disease and Addison’s disease.

This information is solely for informational purposes. IT IS NOT INTENDED TO PROVIDE MEDICAL ADVICE. Neither the Editors of Consumer Guide (R), Publications International, Ltd., the author nor publisher take responsibility for any possible consequences from any treatment, procedure, exercise, dietary modification, action or application of medication which results from reading or following the information contained in this information. The publication of this information does not constitute the practice of medicine, and this information does not replace the advice of your physician or other health care provider. Before undertaking any course of treatment, the reader must seek the advice of their physician or other health care provider.

Originally Published: Apr 4, 2006

Control of Endocrine Activity

Control of Endocrine Activity

The physiologic effects of hormones depend largely on their concentration in blood and extracellular fluid. Almost inevitably, disease results when hormone concentrations are either too high or too low, and precise control over circulating concentrations of hormones is therefore crucial.

The concentration of hormone as seen by target cells is determined by three factors:

  • Rate of production: Synthesis and secretion of hormones are the most highly regulated aspect of endocrine control. Such control is mediated by positive and negative feedback circuits, as described below in more detail.
  • Rate of delivery: An example of this effect is blood flow to a target organ or group of target cells – high blood flow delivers more hormone than low blood flow.
  • Rate of degradation and elimination: Hormones, like all biomolecules, have characteristic rates of decay, and are metabolized and excreted from the body through several routes. Shutting off secretion of a hormone that has a very short halflife causes circulating hormone concentration to plummet, but if a hormone’s biological halflife is long, effective concentrations persist for some time after secretion ceases.
Feedback Control of Hormone Production

Feedback circuits are at the root of most control mechanisms in physiology, and are particularly prominent in the endocrine system. Instances of positive feedback certainly occur, but negative feedback is much more common.

Negative feedback is seen when the output of a pathway inhibits inputs to the pathway. The heating system in your home is a simple negative feedback circuit. When the furnace produces enough heat to elevate temperature above the set point of the thermostat, the thermostat is triggered and shuts off the furnace (heat is feeding back negatively on the source of heat). When temperature drops back below the set point, negative feedback is gone, and the furnace comes back on.

Feedback loops are used extensively to regulate secretion of hormones in the hypothalamic-pituitary axis. An important example of a negative feedback loop is seen in control of thyroid hormone secretion. The thyroid hormones thyroxine and triiodothyronine (“T4 and T3”) are synthesized and secreted by thyroid glands and affect metabolism throughout the body. The basic mechanisms for control in this system (illustrated to the right) are:

  • Neurons in the hypothalamus secrete thyroid releasing hormone (TRH), which stimulates cells in the anterior pituitary to secrete thyroid-stimulating hormone (TSH).
  • TSH binds to receptors on epithelial cells in the thyroid gland, stimulating synthesis and secretion of thyroid hormones, which affect probably all cells in the body.
  • When blood concentrations of thyroid hormones increase above a certain threshold, TRH-secreting neurons in the hypothalamus are inhibited and stop secreting TRH. This is an example of “negative feedback”.

Inhibition of TRH secretion leads to shut-off of TSH secretion, which leads to shut-off of thyroid hormone secretion. As thyroid hormone levels decay below the threshold, negative feedback is relieved, TRH secretion starts again, leading to TSH secretion.

Another type of feedback is seen in endocrine systems that regulate concentrations of blood components such as glucose. Drink a glass of milk or eat a candy bar and the following (simplified) series of events will occur:

  • Glucose from the ingested lactose or sucrose is absorbed in the intestine and the level of glucose in blood rises.
  • Elevation of blood glucose concentration stimulates endocrine cells in the pancreas to release insulin.
  • Insulin has the major effect of facilitating entry of glucose into many cells of the body – as a result, blood glucose levels fall.
  • When the level of blood glucose falls sufficiently, the stimulus for insulin release disappears and insulin is no longer secreted.

Numerous other examples of specific endocrine feedback circuits are presented in the sections on specific hormones or endocrine organs.

Hormone Profiles: Concentrations Over Time

One important consequence of the feedback controls that govern hormone concentrations and the fact that hormones have a limited lifespan or halflife is that most hormones are secreted in “pulses”. The following graph depicts concentrations of luteinizing hormone in the blood of a female dog over a period of 8 hours, with samples collected every 15 minutes:

The pulsatile nature of luteinizing hormone secretion in this animal is evident. Luteinizing hormone is secreted from the anterior pituitary and critically involved in reproductive function; the frequency and amplitude of pulses are quite different at different stages of the reproductive cycle.

With reference to clinical endocrinology, examination of the graph should also demonstrate the caution necessary in interpreting endocrine data based on isolated samples.

A pulsatile pattern of secretion is seen for virtually all hormones, with variations in pulse characteristics that reflect specific physiologic states. In addition to the short-term pulses discussed here, longer-term temporal oscillations or endocrine rhythms are also commonly observed and undoubtedly important in both normal and pathologic states.

Endocrine Anatomy


























Definition (MSHCZE)

Systém žláz, které uvolňují výměšky (hormony) přímo do oběhového systému. Kromě ENDOKRINNÍCH ŽLÁZ sem patří i CHROMAFINNÍ SYSTÉM a NEUROSEKREČNÍ SYSTÉMY.

Definition (NCI_NCI-GLOSS)

A system of glands and cells that make hormones that are released directly into the blood and travel to tissues and organs all over the body. The endocrine system controls growth, sexual development, sleep, hunger, and the way the body uses food.

Definition (NCI)

Collective designation for those tissues capable of secreting hormones.

Definition (MSH)

The system of glands that release their secretions (hormones) directly into the circulatory system. In addition to the ENDOCRINE GLANDS, included are the CHROMAFFIN SYSTEM and the NEUROSECRETORY SYSTEMS.

Definition (CSP)

ductless glands that secrete substances which are released directly into the circulation and which influence metabolism and other body functions.
Concepts
Body System
(T022)
MSH


D004703
SnomedCT

113331007
LNC LP31396-2, LP7203-5, MTHU001408
English
Endocrine System, Endocrine Systems, System, Endocrine, Systems, Endocrine, Endocrine structure (body structure), Endocrine structure, Structure of endocrine system, Structure of endocrine system (body structure), Systema endocrinum, Endocrine, endocrine systems, endocrine system, endocrine glands system, endocrine gland/system, Endocrine system structure, Endocrine system, Body System, Endocrine/Metabolic, Endocrine/Metabolic Body System, Hormonal System, Organ System, Endocrine/Metabolic, Endocrine/Metabolic Organ System, Metabolic/Endocrine Body System
Swedish
Endokrina systemet
Czech
endokrinní systém
Finnish
Umpieritysjärjestelmä
Russian
ENDOKRINNAIA SISTEMA, ЭНДОКРИННАЯ СИСТЕМА
Croatian
ENDOKRINI SUSTAV
Latvian
Endokrīnā sistēma
Polish
Układ wewnątrzwydzielniczy, Układ endokrynny, Układ wydzielania wewnętrznego
Norwegian
Endokrine system, Hormonsystemet, Hormonene
Spanish
estructura del sistema endocrino (estructura corporal), estructura del sistema endocrino, sistema endocrino, Sistema Endocrino
French
Système endocrine, Système endocrinien
German
Endokrines System
Italian
Sistema endocrino
Dutch
Endocrien systeem, Systeem, endocrien
Portuguese
Sistema Endócrino

Endocrine Hormones

Hormones sent from the hypothalamus to the anterior lobe of the pituitary gland function as signals. They stimulate or inhibit the release of anterior pituitary hormones, which regulate endocrine glands and control a range of body functions. Human growth hormone (hGH) travels to skeletal muscles, bones, and the liver to promote overall growth and development. Thyroid-stimulating hormone (TSH) and adrenocorticotropic hormone (ACTH) target the thyroid and adrenal glands, two primary endocrine glands that regulate metabolism for temperature regulation, growth, and stress resistance. Follicle-stimulating hormone (FSH) and luteinizing hormone (LH) stimulate sex cell production and reproductive processes in the gonads, and prolactin (PRL) induces milk production in mammary glands.

4. Posterior Pituitary Hormones Regulate Water Levels and Induce Labor

Most hormones secreted by the hypothalamus travel to the anterior lobe of the pituitary, where they stimulate or inhibit the release of other hormones. But two, antidiuretic hormone (ADH or vasopressin) and oxytocin (OXT), are secreted into the posterior pituitary lobe by axonal extensions from the hypothalamus. The posterior pituitary stores ADH and OXT and releases them directly into the bloodstream when needed. ADH acts on the kidneys, blood vessels, and sweat glands in the skin to reduce water loss throughout the body. OXT factors into pregnancy and nurturing. It causes smooth muscle contractions of the uterus to induce birth. Later it stimulates milk ejection from the mammary glands and promotes bonding between mother and child.

5. Hormones Fuel the Body’s Response to New Stimuli and Stress

Hormones control ongoing internal functions. They also enable our body’s reactions to changes in the environment — for example, when we perceive a sudden threat or find ourselves under stress. In this case, the hypothalamus commands the adrenal glands directly (via nervous signals) to ramp up production of epinephrine and norepinephrine. These hormones promote the “fight-or-flight” response: breathing and heart rate increase and our muscles get a burst of energy. If the situation continues, the endocrine system kicks into the “resistance phase”: The hypothalamus directs the pituitary to release adrenocorticotropic hormone (ACTH). The ACTH stimulates the adrenal glands to release mineralocorticoids and glucocorticoids, and the pancreas secretes glucagon. These hormones increase blood sugar and sustain elevated blood flow and energy levels for prolonged stress.

Endocrine System Function & Hormone Regulation – Video & Lesson Transcript

The endocrine system, a complex network of glands with several key functions

Endocrine System Function

The main function of the endocrine system is to regulate and monitor the levels of hormones circulating in the blood. This is because the endocrine system produces hormones that can regulate moods, growth, metabolism, development, and reproduction, which are released in accordance to what the body needs. One gland, the pituitary gland, is primarily responsible for sensing when hormone levels are increased and relays information to the other glands to stop producing the hormones. The pituitary gland can also sense when hormone levels are too low and instruct other glands to start producing more hormones.

Hormones affect several processes in the body, such as:

  • Metabolism
  • Sleep
  • Sexual development and function
  • Blood pressure
  • Temperature
  • Development and growth

Parts of the Endocrine System

The endocrine system consists of several parts, including the major glands that make up this network. They include the hypothalamus, the pituitary, thyroid, parathyroid, thymus, and adrenal glands, and the pancreas.

Hypothalamus

Located in the middle part of the brain, the hypothalamus is responsible for regulating and controlling the endocrine system. It combines information from the nervous system and the other glands of the endocrine system in order to regulate which hormones should be produced. The hypothalamus is intimately connected to the pituitary gland, which is the gland responsible for producing the hormones. The hypothalamus controls several processes, including sleep, mood, hunger, thirst, and sexual function.

Pituitary Gland

The pituitary gland is a pea-sized component of the endocrine system that produces the hormones that controls other glands, such as the thyroid and adrenal glands, in addition to testes and ovaries. In fact, the pituitary gland signals the sex glands to release the hormones when the body reaches a certain age. It is also located in the brain, and mediates bodily functions like blood pressure, water balance, and how the body develops.

Thyroid Gland

Located at the front of the neck, the thyroid gland is a butterfly-shaped gland that is primarily responsible for metabolism, or how the body uses energy. The thyroid achieves this by producing the thyroid hormone in appropriate levels to maintain the body’s metabolism. Too much of this hormone results in sleeplessness and a high metabolism, whereas too little can result in weight gain and feeling slow.

Parathyroid Gland

The parathyroid gland consists of four smaller glands located behind the thyroid that are important in maintaining bone health. They do so by balancing the levels of calcium throughout the blood, which is critical for organs like the heart and kidneys to function appropriately.

Thymus Gland

The thymus gland produces white blood cells known as T-lymphocytes which are critical in the body’s fight against infections. It is thus an important gland for the immune system, especially in children, and the thymus begins to shrink after an individual reaches puberty.

Adrenal Gland

Known for producing adrenaline, the adrenal glands are responsible for the body’s fight or flight response. Apart from that, these two glands are responsible for controlling processes like blood pressure, sexual development, metabolism, and how the body responds to stress.

Pancreas

The pancreas is a major part of the endocrine system because it has significant roles in the digestive system. This is because the pancreas produces insulin, which is an important hormone that regulates the level of sugar in the blood. When the body has a high level of sugar, the pancreas produces more insulin to help break it down. Importantly, sugar is the primary energy source for the body, and so the pancreas controls energy levels.

Insulin can be administered externally, which is necessary for sugar breakdown in the blood.

How Does the Endocrine System Work?

The endocrine system works by continuously monitoring the level of hormones in the blood, essentially having a pivotal role in the body’s homeostasis, which is the steady balance of conditions and processes in the body. This corresponds to metabolic balance in the body, and is important for optimal bodily functioning. The endocrine system achieves this by regulating several processes, including cellular metabolism; homeostasis of sugar and other key nutrients; and regulation of blood pressure and heart rate, sleep, digestion, and sexual development.

When released from the glands, hormones travel through the blood to the target organ or cell where the effect of the hormone will be carried out. This is because the target cell contains specific receptors that the hormone attaches and binds to, which initiates a cascade of events, like cellular changes, corresponding to the hormone’s function. This process is highly regulated by other glands in the endocrine system. For example, when the body is experiencing a lot of stress, the hypothalamus releases hormones into the blood that travel to the pituitary gland, which produces the appropriate hormones that signal the adrenal glands to produce the stress hormone cortisol. When the body no longer requires cortisol, a feedback signaling mechanism halts the production of this hormone via the hypothalamus and pituitary gland.

Lesson Summary

The endocrine system is an essential network in the body that consists of glands, which are organs that produce chemicals known as hormones that travel to target sites on cells, organs, and tissues. Key functions include metabolism, sleep, temperature, blood pressure, and development.

There are several parts of the endocrine system, and they are intricately connected to maintain appropriate levels of hormones in the body to maintain the body’s homeostasis. The hypothalamus combines information from the endocrine system with the nervous system and regulates the production of hormones through its connection to the pituitary gland, which produces the hormones. The thyroid gland is responsible for the body’s metabolism, and the parathyroid gland for the regulation of calcium in the blood. The thymus gland is essential for the body’s immune system since it produces white blood cells, and the adrenal gland is essential for the body’s fight-or-flight response by releasing adrenaline. Lastly, the pancreas regulates the sugar levels in the blood by producing insulin.

The endocrine system works by maintaining the body’s homeostasis through the regulation of the hormones produced and secreted. Such metabolic balance is achieved by regulating the body’s cellular metabolism, balancing the levels of sugar and other nutrients, and the regulation of blood pressure and heart rate, sleep, and digestion. Upon release, hormones travel to target tissues which contain specific receptors. When the hormones bind to the receptors, a cascade of events occur towards achieving the hormone’s function.

13.25: Glands – Biology LibreTexts

What’s a hormone?

This messenger pigeon is delivering a letter, making sure it gets to where it needs to go. It could be said that hormones are biological messengers, and they originate from the endocrine system. The nervous system isn’t the only message-relaying system of the human body. The endocrine system also carries messages. The endocrine system is a system of glands that release chemical messenger molecules into the bloodstream. The messenger molecules are hormones. Hormones act slowly compared with the rapid transmission of electrical messages by the nervous system. They must travel through the bloodstream to the cells they affect, and this takes time. On the other hand, because endocrine hormones are released into the bloodstream, they travel throughout the body. As a result, endocrine hormones can affect many cells and have body-wide effects.

Glands of the Endocrine System

The major glands of the endocrine system are shown in Figure below. You can access a similar, animated endocrine system chart at the link below.

The glands of the endocrine system are the same in males and females except for the testes, which are found only in males, and ovaries, which are found only in females.

Hypothalamus

The hypothalamus is actually part of the brain (see Figure below), but it also secretes hormones. Some of its hormones “tell” the pituitary gland either to secrete or to stop secreting its hormones. In this way, the hypothalamus provides a link between the nervous and endocrine systems. The hypothalamus also produces hormones that directly regulate body processes. These hormones travel to the pituitary gland, which stores them until they are needed. The hormones include antidiuretic hormone and oxytocin.

  • Antidiuretic hormone stimulates the kidneys to conserve water by producing more concentrated urine.
  • Oxytocin stimulates the contractions of childbirth, among other functions.

The hypothalamus and pituitary gland are located close together at the base of the brain.

Pituitary Gland

The pea-sized pituitary gland is attached to the hypothalamus by a thin stalk (see Figure above). It consists of two bulb-like lobes. The posterior (back) lobe stores hormones from the hypothalamus. The anterior (front) lobe secretes pituitary hormones. Several pituitary hormones and their effects are listed in Table below. Most pituitary hormones control other endocrine glands. That’s why the pituitary is often called the “master gland” of the endocrine system.

Hormone Target Effect(s)
Adrenocorticotropic hormone (ACTH) Adrenal glands Stimulates the cortex of each adrenal gland to secrete its hormones.
Thyroid-stimulating hormone (TSH) Thyroid gland Stimulates the thyroid gland to secrete thyroid hormone.
Growth hormone (GH) Body cells Stimulates body cells to synthesize proteins and grow.
Follicle-stimulating hormone (FSH) Ovaries, testes Stimulates the ovaries to develop mature eggs; stimulates the testes to produce sperm.
Luteinizing hormone (LH) Ovaries, testes Stimulates the ovaries and testes to secrete sex hormones; stimulates the ovaries to release eggs.
Prolactin (PRL) Mammary glands Stimulates the mammary glands to produce milk.

Other Endocrine Glands

Other glands of the endocrine system are described below. You can refer to Figure above to see where they are located.

  • The thyroid gland is a large gland in the neck. Thyroid hormones increase the rate of metabolism in cells throughout the body. They control how quickly cells use energy and make proteins.
  • The two parathyroid glands are located behind the thyroid gland. Parathyroid hormone helps keep the level of calcium in the blood within a narrow range. It stimulates bone cells to dissolve calcium in bone matrix and release it into the blood.
  • The pineal gland is a tiny gland located at the base of the brain. It secretes the hormone melatonin. This hormone controls sleep-wake cycles and several other processes.
  • The pancreas is located near the stomach. Its hormones include insulin and glucagon. These two hormones work together to control the level of glucose in the blood. Insulin causes excess blood glucose to be taken up by the liver, which stores the glucose as glycogen. Glucagon stimulates the liver to break down glycogen into glucose and release it back into the blood. The pancreas also secretes digestive enzymes into the digestive tract.
  • The two adrenal glands are located above the kidneys. Each gland has an inner and outer part. The outer part, called the cortex, secretes hormones such as cortisol, which helps the body deal with stress, and aldosterone, which helps regulate the balance of minerals in the body. The inner part of each adrenal gland, called the medulla, secretes fight-or-flight hormones such as adrenaline, which prepare the body to respond to emergencies. For example, adrenaline increases the amount of oxygen and glucose going to the muscles.
  • The gonads secrete sex hormones. The male gonads are called testes. They secrete the male sex hormone testosterone. The female gonads are called ovaries. They secrete the female sex hormone estrogen. Sex hormones are involved in the changes of puberty. They also control the production of gametes by the gonads.

Summary

  • The endocrine system consists of glands that secrete hormones into the bloodstream.
  • The endocrine system is regulated by a part of the brain called the hypothalamus, which also secretes hormones.
  • The hypothalamus controls the pituitary gland, which is called the “master gland” of the endocrine system because its hormones regulate other endocrine glands.
  • Other endocrine glands include the thyroid gland and pancreas.

Review

  1. Explain how the nervous system is linked with the endocrine system.
  2. List five of the major glands of the endocrine system.
  3. Name three pituitary hormones, and state how they affect their targets.

Endocrine System Anatomy & Physiology For The MBLEx

The endocrine system consists of endocrine glands that produce hormones. These hormones function as chemical messengers that circulate through the body and tell other organs and tissues what to do. By doing this, the endocrine system plays a vital role in helping the body to coordinate all of its activities and maintain homeostasis.

This post gives an overview of the endocrine system anatomy & physiology. It also highlights the most important components and functions that a massage student or therapist needs to know to prepare for the MBLEx in 2021.

Primary functions of the endocrine system

The primary function of the endocrine system is regulation of other body organs and tissues. It does this by secreting hormones, which are very small and powerful chemical messengers.

For example, the hormone thyroxine (T4) is produced in the thyroid gland and then it travels through the bloodstream to affect almost every other system in the body. It plays and important role in metabolism, heart function, digestive function, brain development and muscle control.

In order for the body to maintain homeostasis and function properly, all organs must work in harmony. The hormones produced by the endocrine system are like the body’s internal communication system. Once produced by the endocrine glands, hormones are then secreted into the tiny capillaries around the gland, and then carried by the bloodstream to their target.

Some of the body functions that the endocrine system influences include: metabolism, growth and development, movement, respiration, cardiac output, reproduction, and sensory perception. Damage to an endocrine gland or other causes of hormone imbalance will usually affect multiple body systems.

The endocrine system works closely with the nervous system. In fact they both function as messenger systems within the body. The difference is that the endocrine system uses hormones to send its messages and the nervous system uses electrical signals to send its message.

Getting ready to take the massage exam? Be sure to check out our Ultimate Guide To Passing The MBLEx.

Components of the endocrine system

The endocrine system is composed of a collection of endocrine glands that produce hormones. Endocrine glands are different from exocrine glands. Exocrine glands like sweat glands and sebaceous glands have ducts that carry their substances to the surface. However the glands of the endocrine system are ductless. This means they secrete their hormones directly into the bloodstream via the tiny capillaries around the endocrine glands.

Once in the bloodstream, the hormones are carried throughout the body. Hormones only affect their target cells, which have specific receptor sites for the hormone. A hormone is kind of a tourist walking around the city looking for someone who speaks her language. When she finds someone who speaks her language then she can deliver her message. The message that the hormone is delivering is to tell the organ or tissues to do something, like speed up or slow down their work.

Below is a list of endocrine glands and a few of the main hormones that each gland produces. You may see one or two of these on the MBLEx. The depth and detail required on the MBLEx will likely be less than that required in your anatomy and physiology class. So focus on the major concepts and terminology.

Pituitary

The pituitary gland is known as the “master gland” because it controls the function of many other endocrine glands. This small gland that is located in a cavity within the sphenoid bone of the skull.

The pituitary is a single structure, but it is often divided into the anterior pituitary and posterior pituitary when discussing its different functions. The anterior pituitary gland produces more hormones, many of which target other endocrine glands. Hormones of the anterior pituitary gland include:

  • Human growth hormone (hGH)
  • Adrenocorticotropic hormone (ACTH)
  • Follicle-stimulating hormone (FSH)
  • Thyroid-stimulating hormone (TSH)
  • Luteinizing hormone (LH)
  • Prolactin
  • Melanocyte-stimulating hormone

Hypothalamus

The hypothalamus functions as a bridge between the nervous system and the endocrine system. It is located just above the pituitary gland, and anterior to the brain stem. The hypothalamus controls the pituitary gland to a great extent. It also produces the hormones oxytocin and antidiuretic hormone (ADH).

Pineal

The pineal gland is a pea-sized gland in the brain that produces melatonin, which regulates the body’s sleep cycle. This is also known as circadian rhythm.

Thyroid

The thyroid gland is a butterfly-shaped endocrine gland located on the anterior side and wrapping around to the lateral sides of the trachea. It produces 3 main hormones:

  • Triiodothyronine (T3): works to regulate metabolic rate and increase cellular activity.
  • Thyroxine (T4): similar function as T3.
  • Calcitonin: regulates the amount of calcium ions in the blood.

Parathyroid

The parathyroid gland consists of 4 small masses of endocrine tissue located on the posterior side of the thyroid gland. It produces the hormone parathyroid hormone (PTH), which is used to regulate the balance of calcium ions and phosphorus levels in the blood.

Pancreas

The pancreas is located behind the stomach, and has both endocrine and exocrine functions. As an exocrine gland, it is an accessory organ to the digestive system. The endocrine function of the pancreas involves a very small part of the organ (about 1% by mass), but it is a very important role.

Cells in the islets of Langerhans produce 2 hormones that help regulate blood glucose levels.

  • Alpha cells: produce glucagon which raises blood glucose levels
  • Beta cells: produce insulin which lowers blood glucose levels

Adrenal glands

There are two adrenal glands, one at the superior aspect of each kidney. The adrenal glands (also called the suprarenal glands because of their location) produce three classes of hormones.

  • Glucocorticoids: involved with the immune response and in the production of glucose.
  • Mineralocorticoids: help to regulate the balance of minerals in the body.
  • Androgens: hormones involved with growth.

Gonads

These endocrine glands are the ovaries and testes. The gonads produce hormones such as testosterone, progesterone and estrogen, which are involved with growth and development.

Thymus

The thymus is located behind the sternum. It plays a role in the development of the body’s immune function during childhood. After puberty, the job of the thymus is over and the gland gets replaced by adipose tissue.

Interaction between the endocrine system and other systems

The endocrine system has a lot of influence over the activities of other body systems and organs. These systems also influence the endocrine system. The following is a few basic ways that these systems interact.

Circulatory system

The endocrine system uses hormones to regulate heart rate, blood pressure, blood volume, red blood cell production, and strength of heart contractions. The circulatory system helps the endocrine system by transporting hormones to their target organs and tissues.

Muscular system

Hormones affect muscle growth and strength, as well as control smooth muscle activity.

Skeletal system

The skeletal system provides protection for glands such as those in the cranial cavity, and the thymus located behind the sternum. The endocrine system uses hormones to regulate calcium levels, skeletal growth and development.

Integumentary system

Hormones of the endocrine system can affect integumentary system by effecting skin coloring, hair growth, and the activity of sebaceous glands.

Respiratory system

The hormone epinephrine produced by the adrenal glands affects the respiratory system when exercising or under stress (part of the “fight or flight” response). Epinephrine widens the airways to facilitate breathing.

Urinary system

Hormones of the endocrine system such as aldosterone and antidiuretic hormone influence kidney function. The kidneys in turn help to break down and eliminate inactivated hormones.

Digestive system

The endocrine system helps to regulate the production of enzymes produced by the digestive system. Hormones influence the motility of the intestinal tract by affecting the smooth muscle in the wall of the GI tract.

Lymphatic system

Glucocorticoids produced by the adrenal glands help to suppress the immune response and decrease inflammation.

Nervous system

Hormones help in the development and normal function of the nervous system. The parathyroid hormone regulates calcium ion levels, which are needed to generate nerve impulses.

Reproduction system

Hormones of the endocrine system play a major role in the development and function of reproductive organs.

How massage therapy affects the endocrine system

Massage therapy likely has a physiological affect on the endocrine system. For example, many types of massage will stimulate a relaxation response. This response is usually associated with a decrease in hormones such as cortisol.

Massage and bodywork also activates the parasympathetic nervous system. This will stimulate a relaxed physiological and psychological state. A relaxed body and mind produces different hormones than one that is stressed or anxious.

A stressed body will produce the hormones adrenaline, norepinephrine and cortisol. On the other hand, a relaxed body will produce hormones like oxytocin, endorphins, serotonin and dopamine.

Research on specific affects of massage therapy is often inconclusive, biased or conflicting. It stands to reason though that the benefits of massage for conditions such as anxiety, depression, pain and stress aren’t due to dramatic changes in a single hormone, but rather a combined affect across multiple body systems.

This covers some of the most important aspects of the endocrine system that massage therapists will likely see on the MBLEx in 2021. If you have a few minutes, try out a couple of free practice quizzes.

Treatment of endocrine system disorders in Zaporozhye

Hormones are important components in the physiology of the body. Development of human height and weight is impossible without hormones. They regulate many vital processes in the body. Hormones are involved in the formation of the skeleton, muscle tissue and other organs, systems, tissues and cells of the body.

Hormones are produced by various organs – thyroid and pancreas, hypothalamus, testes and ovaries, pituitary gland, thymus gland, adrenal glands and other organs.

CAUSES OF ENDOCRINE DISEASES

Disorders of the endocrine system can occur for reasons associated with a genetic predisposition, under the influence of external factors.

Common causes of endocrine disorders are:

  • frequent stressful conditions;
  • decline of immune functions;
  • age-related changes;
  • viral and bacterial infections;
  • invasive diseases;
  • consequences of heart attacks.

In addition, smoking, alcohol abuse, and uncontrolled intake of medications can be provoking factors in the development of endocrine system pathologies. Among the reasons may be problems of the digestive tract, problems with insomnia.

SIGNS OF DISORDERS OF THE ENDOCRINE SYSTEM

Pathologies in the physiology of hormone-producing organs, disorders of the entire endocrine system are accompanied by signs of disorders in various organs.Symptoms of diseases in endocrine disorders can be general and characteristic. The most common symptoms are:

  • thirst or dry mouth;
  • a sharp change in body weight;
  • decreased vision;
  • abundant hair growth;
  • dermatitis and itching;
  • Rapid fatigue, especially during physical exertion;
  • the appearance of skin defects – folds, seals, puffiness.

TREATMENT OF ENDOCRINE DISEASES

Before prescribing a course of treatment, it is necessary to establish the actual level of the endocrine system.The indicators are different for men and women. To prescribe a more correct treatment, the doctor establishes an anamnesis, conducts a clinical examination. If necessary, prescribes additional laboratory examinations, ultrasound examination of the organs responsible for the production of certain hormones.

The further course of treatment includes vitamin therapy, restoration of immune functions. In some cases, the doctor prescribes replacement therapy with special medications.

If pathological consequences are detected, symptomatic treatment is carried out.At the same time, drugs and methods that regulate the work of the endocrine system can be prescribed.

To achieve the maximum effectiveness of the treatment of such pathologies, it is possible to correctly diagnose and prescribe a course of treatment in a timely manner. Much depends on the competence of the endocrinologist.

You can consult a qualified endocrinologist at the Oxford Medical Zaporozhye Medical Center.

You can make an appointment with an endocrinologist by phone in Zaporozhye: 233 7 233.

Endocrine system / Course / Entomology

The insect endocrine system is formed by heterogeneous neurosecretory cells, a retrocerebral complex, a prothoracic larval gland and neurohemal organs. Taking part in the management of metabolic processes, coordinating and integrating the activities of various systems of the body, it obeys the nervous system and mediates its functions at the level of humoral influences. At the same time, the endocrine system controls the course of development and reproduction of insects.

Neurosecretory cells of the brain

Differing from neurons in their ability to synthesize hormones, they are dispersed throughout all ganglia of the nerve chain, forming several separate groups in the brain. Differing in their affinity for certain dyes, these cells are divided into four types, designated A (A ‘, A’ ‘), B, C, D. However, not all cells of the same type secrete secrets with similar physiological properties. The cells of the medial group of the brain, located near the ocellar nerves, have axons directed to the opposite sides of the protocerebrum (Fig.129), where they penetrate into the first pair of cardiac nerves.

Figure 129. The neurosecretory system of the brain of insects (according to Tyschenko, 1977):

1 – medial and lateral neurosecretory cells; 2 – tritocerebrum; 3 – cardiac body; 4 – adjacent body; 5 – recurrent nerve

Coming out of the brain, these nerves are directed to the cardiac bodies (corpora cardiaca), and sometimes to the adjacent bodies (corpora allatum) of the retrocerebral complex.Groups of lateral neurosecretory cells form the second pair of cardiac nerves, and their third and fourth pairs are formed by the corresponding cells of the deutocerebrum and tritocerebrum. In addition, neurosecretory elements are found in the optical lobes of some insects. A and B cells of the medial groups of the locust protocerebrum Locusta migratoria L . synthesize substances that inhibit the activity of adjacent bodies and affect protein metabolism in the hemolymph, C-cells – substances that stimulate adjacent bodies and the synthesis of melanins, and D-cells form a diuretic hormone.Medial A ‘- silkworm cells Bombux mori L . produce an activation hormone, and B cells of the suboesophageal ganglion produce substances that induce diapause.

Retrocerebral complex

The cardiac bodies, in addition to the four pairs of nerves extending from the brain, have connections with the stomatogastric nervous system and are considered as its ganglia. Clothed with a connective tissue membrane, they have their own neurosecretory elements and neurons, as well as neuroglial cells.Often, cardiac bodies grow together into an unpaired ganglion or (for example, in flies) form, together with the adjacent bodies and the prothoracic gland, an annular gland. Cockroach Periplaneta americana L . they secrete activation hormone (AG), hyperglycemic hormone, neurohormone D, which stimulates heartbeat, and a substance that affects the conduction of nervous excitement; in peacock-eyed butterflies, substances associated with the synthesis of sex attractants or stimulating egg laying.

Not all of these hormones and physiologically active substances are synthesized by the cardiac bodies, which, along with secretory functions, play the role of neurohemal organs, that is, organs that store neurosecrets of the brain.

In particular, the activation hormone only accumulates in them, as well as the hormone that induces the hatching of butterflies from the pupa. In addition to cardiac bodies, neurohemal organs include: aorta (in bedbugs), which deposits neurosecret in its walls; peculiar persympathetic formations, topographically associated with the azygos nerve system; adjacent bodies. The adjacent bodies located behind the cardiac bodies accumulate neurosecretory coming from them, synthesize and release into the hemolymph juvenile hormone (JH), which regulates the course of development and reproduction, metabolic processes, changes in the color of integuments, the intensity of nutrition, as well as inducing diapause and influencing behavior.The adjacent bodies, connected by two pairs of allatal nerves to the cardiac bodies, are at the same time connected by nerves to the suboesophageal ganglion.

Paired prothoracic glands, usually located in the thoracic region and included in the annular gland in Diptera, are present only in larvae. Degenerating during the transition of the organism to an adult state, they persist throughout life only in some primary wingless insects, mayflies, single phases of locusts, and in working termites. Not connected as closely as the components of the retrocerebral complex with the nervous system, the prothoracic glands are often not innervated at all.However, by means of humoral influences spreading along the hemolymph, they clearly depend on the neurosecret of the brain, reacting with the release of the molting hormone – ecdysone. Essentially, the prothoracic glands are a component of a single insect endocrine system, which in many respects resembles the endocrine system of vertebrates. Moreover, unlike vertebrates, insects seem to lack sex hormones that determine the development of secondary sexual characteristics, and only in firefly beetles Lamipyris noctiluca L .when the testes are transplanted into the body of the developing female larva, the sex is reversed and signs characteristic of the male appear. The androgenic hormone presumably acting in this case has not yet been isolated.

There is also evidence of the presence in mature ovaries of the fly Musca domestica L . oostatic hormone, which prevents the development of the next batch of eggs until the already formed eggs are laid. This hormone, synthesized in the ovaries, inhibits the secretion of neurosecretion by the medial cells of the brain.In turn, the production of juvenile hormone, which is necessary to stimulate the activity of the ovaries, depends on this neurosecret. The antigonadotropin of the bug Rhodniusprolixus St , similar in nature, blocks the activity of the juvenile hormone itself directly in the ovaries without affecting other endocrine organs.

Hormones

Insects have discovered a whole spectrum of hormones of various actions, but not all of them have been identified. Activation hormone (AG), the manifestations of which were noted earlier than others (in 1922, apparently, formed by two components: one of them stimulates the synthesis of RNA, the other affects the membrane permeability and the membrane potential of the cells of the prothoracic gland.The assumption about the identity of AH with cholesterol was not confirmed, but when the fractions of the neurosecret of medial cells of the protocerebrum were isolated, their activity was increased by 8000 times. At the same time, three main fractions with different molecular weights were isolated.

Acting on the prothoracic glands, hypertension induces them to synthesize ecdysone, a hormone that causes the onset and passage of molting, as well as sclerotization of the integument when combined with bursicon. There is evidence of the possibility of ecdysone production by hemocytes, cells of the adipose body and enocytes.

After Butenandt and Carlson, having processed 500 kg of silkworm pupae in 1954, obtained 25 mg of a pure crystalline product, it was shown that it was formed by two steroids: α- and β-ecdysones. Contrary to the point of view (3-ecdysone as a by-product of β-ecdysone synthesis, there is evidence that β-ecdysone synthesized in the prothoracic glands is a precursor of the main hormone (3-ecdysone, the synthesis of which occurs in enocytes and, possibly, in cells fatty body.

Currently, the following metabolic series is recognized as valid: cholesterol – 22, 25-deoxyecdysone – 22-deoxyecdizone – β-ecdysone – (3-ecdysone. It is essential that both ecdysones and more than 20 steroids of similar physiological action are isolated from plants, where their content often reaches very high values, for example, up to 0.8 μg per 1 g of dry weight in the tissues of the yew and the nodocarp.However, borrowing steroids from the tissues of fodder plants, insects independently synthesize cholesterol and substances of all subsequent stages of the metabolic pathway of ecdysone.

The main targets for ecdysone are cells of the hypodermis and imaginal discs, more precisely, the chromosomes of these cells. From the standpoint of the membrane hypothesis, ecdysone, causing changes in the permeability of intracellular membranes for ions, stimulates puffing – the formation of local bulges on chromosomes, corresponding to foci of intense mRNA synthesis and reading of genetic information. In the polytene (multi-filamentous) chromosomes of the salivary glands of dipterans, these swellings (puffs) appear in a sequence corresponding to the course of the molting process.The introduction of ecdysone provokes the implementation of this puffing sequence on the chromosomes of even an adult insect.

As an alternative, a depressor hypothesis of the effect of ecdysone on chromosomes was put forward. Awakening the operons responsible for the synthesis of specific enzymes, ecdysone, in accordance with this hypothesis, directly determines the sequence of reading genetic information.

Thus, ecdysone determines the onset and passage of the molar process, but its character and result depend on the juvenile hormone produced by the adjacent bodies.Chemical analysis and synthesis of compounds with the action of JH allowed us to identify three closely related terpenoids, conventionally named JG-I, JG-II, JG-III. Many other compounds that reproduce the effects of these terpenoids have also been discovered and synthesized. Called juvenile hormone analogs, or juvenoids, they were isolated from plants and animals or synthesized artificially.

It is noteworthy that the stimulus to the search for Yug analogues was the cardboard cages made of balsam fir wood, in which the nymphs of soldier bugs ( Pyrrhocoris apterus L .) did not become adults, sexually mature individuals.

Among juvenoids, synthetic noncyclic sesquiterpenes close to insect hormones – farnesol and its derivatives, as well as monocyclic sesquiterpenes of the Juvabion type – have become especially famous. Due to the pronounced specificity of the action, natural and synthetic juvenoids are used to combat certain types of pests of agricultural crops.

In the presence of juvenile hormone in the hemolymph, molting insects undergo only limited transformations, characteristic, for example, for the transition from one preimaginal stage to another.

Transformations into adults, especially abrupt upon complete transformation, become impossible in the presence of juvenile hormone. That is why it is sometimes called neotenin (hormone of the young), or the hormone of the status quo.

During development, the main targets of the hormone are the cells of the hypodermis, and in fully developed females, the ovaries. According to the reverse hypothesis, two or three types of genes (larval, pupal, and imaginal) are present in the cells of insect hypodermis, which are activated at different concentrations of the hormone.From the position of the repressor hypothesis, the action of JH is manifested through the suppression of the operons responsible for the formation of imaginal organs and structures. However, the possibility of the appearance of larval traits in pupae of the Great Meal Beetle (reversion) contradicts this assumption. At the same time, JH, apparently, promotes the synthesis of tRNA, which establishes an order in the arrangement of amino acids of proteins synthesized on ribosomes.

Therefore, insect hormones perform a variety of functions – from regulating gene activity to inducing diapause.However, they are primarily responsible for reproduction and development, extending their influence down to individual acts of behavior associated with these processes. For example, JH is able to increase the locomotor activity of male locusts or the readiness for mating of female Drosophila Drosophila melanogaster Mg . Ecdysone, synthesized under the influence of eggs maturing in the ovary, can block the aspiration of female mosquito Anopheles freebomi Zt. to bloodsucking, necessary for the formation of the next batch of eggs.The extracts of the cardinal bodies, stimulating the phallic nerve of the cockroach Periplaneta americana L ., Provide the realization of the stereotype of sexual behavior.

In conclusion, we note that the endocrine system of insects, coordinating metabolic processes and the course of development, is a system of long-term processes and reactions. In this respect, it is opposed to the nervous system, which forms rapid responses to transient stimuli. In addition, not having its own means of reception, the endocrine system is closely dependent on stimuli mediated by nervous excitement, and together with the nervous system ensures the integration of all vital functions, directing them on the path of procreation.

RESULTS AND PROSPECTS OF ITS STUDY

77

CURRENT ISSUES OF ENDOCRINOLOGY

of the inner plate of the visceral leaf of the mesoderm)

Secrete the same biogenic innos, amines, amines 9000, adrenaline 9000 , glucagon, vasointestinal peptide, soma-

tostatin, cholecystokinin, substance P, bombesin, etc.).

Analyzing this problem from biochemical, physiological,

and histogenetic positions, it should be admitted

that the chemical structure of biologically active

substances (biogenic amines, peptide hormones,

enzymes, etc.) did not fundamentally change during the

evolution of animals, i.e. reflected the expression of the universal

greasy elementary block of the genotype of both unicellular

exact and multicellular animals [32]. Suffice it to say

that the formation of lactic acid both in bacteria and in human muscles requires the participation of the same

enzymes. Representatives of the sponge type (intestinal

lobes) have nerve cells that secrete

the entire set of regulatory peptides inherent in human neurons

.In some species of amphibians, skin cells

contain the entire set of peptide hormones, which

are secreted by cells of the gastroenteropancreatic

human endocrine system. However, skin peptides

of amphibians are mainly used by them as

poisons to protect against animal attacks. In other words

, the same universal elementary

functional block can be used in the body

for the production of a mediator, hormone, poison or other

biological active substance in various

cellular tissue elements.Moreover, in the process of cell differentiation

, they can express either one

elementary block, or several at the same time. This,

, respectively, will be manifested by a specific

set of markers of cytodifferentiation, regardless of

histogenetic affiliation of cells to a particular tissue

[33]. Recognition of the fact that DES

cells can develop from embryonic rudiments of ecto-,

ento- and mesoderm, but in the process of cytodifferentiation

of their cells use the same elementary functional

functional blocks of biogenic amine formation

and peptide hormones, explains the presence in them of the same

and the same markers of cytodifferentiation.At the same time,

each cytogenetic line of differentiation

cells has the specificity of the chemical composition of the intermediate

cytoskeleton filaments (cytogenetic

markers), which may reflect the cytogenetic features of their development and sensitivity2 when using chemotherapy

radiotherapy as a therapeutic effect

on tumors of various histogenetic

origin.All this requires a scientifically grounded

approach to revising the histogenetic classification of

tumors originating from DES cells, since to the present

they are considered neuroendocrine [34-36].

Problems of structural and functional organization

DES. In this problem, it will be expedient to consider the questions of the structure of DES cells, their classification,

localization and function of the hormones secreted by them.

Structurally, DES is an endoepi-

telial endocrine gland of the mosaic-cell type

[37]. It is formed by a complex of singly located

receptor-endocrine cells, the main

mass of which is located in the epithelial tissues of the mucus

stony membranes of the digestive and respiratory organs,

of the genitourinary system and other organs. DES

cells are characterized by a moderately developed set of organelles,

light cytoplasmic matrix and the presence of secretory

granules, which differ in shape in each cell,

in size and electron density of the contents

[38, 39, 40].Structurally and functionally,

DES cells are subdivided into open and closed cells

of that type. Endocrine cells of the open type are located in the epithelium of the mucous membranes of hollow organs

and contact with their apical ends the contents of these organs. At the apical ends there are

microvilli, the membrane of which contains

receptor proteins. Perceiving information from the external environment

of the body, open-type DES cells react

by secreting hormones.Endocrine cells of the closed type

have no contact with the external environment. They receive

information from the internal environment of the body and also

react by releasing the appropriate hormones [40].

The largest link in DES is the gastroenteric

ropancreatic endocrine system. Its composition

contains the following hormone-producing cells:

A, B, D, D1, Ec, Ecl, I, K, L, Mo, N, P, PP, S, X, YY [12].

A-cells are contained in the endocrine part of the pancreas –

gland. They are also found in the mucous membrane of the

stomach. These are closed cells. They secrete glu-

cagon, endorphins, gastroinhibitory peptide (GIP)

and cholecystokinin (CCK). Glucagon increases the level of

glycemia, inhibits the permeability of cell membranes

branes, stimulates lipolysis and protein breakdown in cells.

Endorphins regulate blood microcirculation,

have an analgesic effect and maintain the psycho-emotional status of the body.GIP inhibits

the secretion of pepsinogen by the main cells of the fundal

glands of the stomach, blocks the release of a substrate for the formation of hydrochloric acid by parietal cells,

slows down gastric peristalsis, but stimulates the secretion of insulin B cells. CCK

stimulates the contraction of the gallbladder and the secretion of

pancreatic enzymes, affects the motor

activity of the gastrointestinal tract and enhances the action of secretin.

B-cells are located in the endocrine part of the under-

of the gastric gland. These are closed cells. They

secrete insulin, which lowers the level of gly-

kemia, promotes the polymerization of glucose into gly-

cogen, increases the permeability of cell membranes

and inhibits the breakdown of proteins in the cell.

D-cells are widespread in the organs of the food –

of the varietal system.They are located in the pancreatic islets

, in the gastric mucosa, tonic

and in the large intestine. These are closed cells.

They secrete somatostatin, which inhibits protein synthesis in cells and the secretion of secretions from the gastric and gastrointestinal tract

.

Somatostatin inhibits the release of gastrointestinal hormones

nal hormones and somatotropic hormone, carbonate

melts the acidic secretion of the stomach and its motor

activity, absorption in the intestine, inhibits the release of bicarbonates and gland enzymes

gland enzymes

selectively reduces blood flow in organs, including

and portal [41].

D1 cells are closed cells, contained

in the endocrine pancreas, stomach

ke, small and large intestines. They secrete vasoin-

testinal peptide (VIP). VIP expands the vessels

of the microcirculatory bed, reduces blood pressure in them

, suppresses the secretion of hydrochloric acid,

stimulates the secretion of pancreatic juice, which is rich in bicarbonates, increases blood levels

of insulin and pancreatic polypeptidase.

Health Committee of St. Petersburg | News

After the end of the temporary medical removal, vaccination can be carried out.

Permanent contraindications to the use of the vaccine “Gam-Covid-Vac”

Contraindications are due to the fact that studies on the tolerability of the vaccine in these people have not been conducted. These contraindications may be changed in the future:

3. What preparation is required before vaccination?

No special training required.Persons who have completed the Patient Questionnaire and have no contraindications to vaccination are allowed to vaccinate. Before vaccination, a mandatory medical examination is carried out with temperature measurement, collection of an epidemiological history, measurement of saturation, heart rate, blood pressure, auscultation of the respiratory and cardiovascular systems, examination of the throat and filling out the Informed Voluntary Consent Form.

4. Do I need to check the antibody level before vaccination?

No, there are no such requirements in the instructions for the vaccine.Those who have had COVID-19 in the last six months are not allowed to get vaccinated. Approaches to vaccinating such citizens will be developed later. Despite the fact that, according to studies, antibodies in people who have been ill in a mild or moderate form often disappear after 4-5 months, it is assumed that they retain T-cell immunity, which continues to protect the body. However, such citizens are encouraged to continue to comply with protective measures.

5. What side effects can there be?

Adverse events specific to the use of a vaccine identified in clinical trials, as well as studies of other vaccines based on a similar technology platform, are predominantly mild to moderate.They develop in the first or second day after vaccination and disappear within 3 consecutive days. More often than others, short-term general and local reactions can develop:

– general – a short flu-like syndrome characterized by chills, fever, arthralgia, myalgia, asthenia, general malaise, headache;
– local – soreness at the injection site, hyperemia or swelling.

The appointment of non-steroidal anti-inflammatory drugs is recommended for fever after vaccination.Less commonly, nausea, dyspepsia, decreased appetite, and sometimes an increase in regional lymph nodes are noted. Some patients may develop allergic reactions.

In case of development of these or other symptoms within the time after the first vaccination, you must inform your doctor about this before the introduction of the second dose of the vaccine.

Plastic component recognized as harmful to the endocrine system – Social responsibility

The European Chemicals Agency, the official EU body responsible for implementing the REACH regulations that regulate the production and circulation of chemicals, has recognized bisphenol A as a hazardous toxin.The compound is used in the plastics industry, including baby bottles, kettles, CDs and DVDs, food containers, sports equipment and household appliances. Reported by The Guardian.

The agency is expected to recommend limiting bisphenol A production next year. The agency stressed that they cannot promise that the substance will be banned. “Most likely, measures will be taken, but not soon,” the organization warned.

Bisphenol A is one of the best-selling chemicals in the world.In 2006, 3.8 million tons of bisphenol A were produced, and about a third went to the European market. Experts from the European Chemicals Agency recognized that the toxin negatively affects the endocrine and reproductive systems of a person, can provoke the development of cancer, diabetes, and reduce the ability to learn.

Bisphenol A was developed as a synthetic mimic of the female sex hormone estrogen. Since 1957, the substance has been distributed as an industrial chemical to produce a type of plastic known as polycarbonate.According to the WHO, the substance enters the human body through plastic dishes when it is heated.

According to a study by French scientists from the University of Poitiers, the substance is found in the urine of more than 90% of the world’s population. Specialists from the German Federal Environment Agency found traces of the substance in the organisms of 591 out of 599 children tested.

ClientEarth, an environmental law firm that has advocated a toxin ban for 20 years, called the decision “historic” and called for early action.“The European Union and national governments need to react quickly to prevent irreversible effects of the chemical on humans and the environment,” said the organization’s lawyer, Alice Bernard.

“The ubiquitous endocrine disrupting chemicals are one of the most pressing health problems today,” said Natacha Cingotti, a spokesman for the Belgian Health and Environment Alliance.She noted that the agency’s conclusion is “long overdue.” It depends on him, according to the expert, whether measures will be taken to reduce the impact of chemicals on humans.

However, environmentalists fear that industrial enterprises will challenge the expert opinion, as did the Association of Manufacturers of Synthetic Materials in Europe, when the agency found that the substance could disrupt the reproductive system.

“We are concerned about this development. We believe that the EU’s principle of making regulatory decisions based on scientific research is being ignored.This will result in uncertainty, and not increase consumer safety, “Jasmine Bird, a spokeswoman for the association, told The Guardian. The specialist cited data from the European Food Safety Authority, according to which the substance is safe for the endocrine system.

Material provided by the “+1” project.

90,000 Sputnik V, EpiVacCorona and KoviVak: what’s the difference?

Russians now have access to three types of domestic vaccines – “Sputnik V” and its demo version “Sputnik Light”, “EpiVacCorona” and “KoviVak”.Which vaccine is best to vaccinate and why? How long will immunity last and will it protect against infection?

Briefly about each vaccine in Russia

“Sputnik V” – a combined vector vaccine of the N.N. N.F. Gamalei. In two doses of the vaccine, there are adenovirus vectors that cannot multiply, which introduce the gene for the coronavirus S-protein into the body. The interval between two injections is three weeks.

Sputnik Light is the first component of Sputnik V, which is administered once.

EpiVacCorona is a peptide vaccine created by FBSI SSC VB “Vector”, which consists of artificially synthesized short fragments of viral proteins. With their help, the immune system learns to recognize and eliminate the virus. The interval between two injections is three weeks

KoviVak – whole-virion vaccine created by the Center.Chumakov. It is based on SARS-CoV-2, devoid of infectious properties, but capable of causing an immune response. The interval between two injections is two weeks.

Are vaccines recognized worldwide?

“Sputnik V” was registered on August 11, 2020 and passed all three phases of clinical trials, and publications with the results of the final trials were published in the authoritative scientific journal The Lancet.

According to the Russian Direct Investment Fund, the use of the Sputnik V vaccine has been approved in more than 65 countries.The vaccine for supply to foreign markets will be produced by RDIF’s international partners in India, Brazil, China, South Korea and other countries. At the same time, the vaccine has not yet been approved by international regulatory agencies: the World Health Organization and the European Medical Agency – they lack thorough, modern standards, post-registration studies and open publication of all data.

EpiVacCorona was registered on October 13, 2020 and will complete the third phase of clinical trials only at the end of this July, as Rinat Maksyutov, Director General of the Vector Center, recently announced.The results of the first and second phases of the EpiVacCorona tests were published only in the Russian scientific journal Infection and Immunity. There are no articles in international journals. In the world, EpiVacCorona is treated with caution, and supply contracts at the St. Petersburg International Economic Forum-2021 have been signed so far only with Brazilian and Venezuelan companies.

KoviVak registered on February 20, 2021, released into civil circulation in March.In early June, phase 3 clinical trials began on volunteers in nine cities. They will end only by the end of December 2022. There have been no peer-reviewed scientific journal publications for this vaccine yet.

How are vaccines developed?

“Sputnik V” was created as follows: scientists took not too pathogenic human adenovirus and deprived it of its ability to reproduce for a long time. After that, they inserted into it fragments of the genome that encodes proteins and corresponds to immunologically important proteins of the coronavirus.A carrier in molecular biology is called a vector – it is an adenovirus.

“Once in the body, the altered virus is taken into the cells and uses them to build a number of proteins,” explains Alexander Chepurnov, a leading researcher at the Institute of Clinical and Experimental Medicine, an ex-employee of Vector. “After that, the immune system sees the proteins of the coronavirus and produces antibodies to their receptor-binding domain.”

“This is how the vaccine helps the immune system to identify the” image of a potential enemy “against which it is necessary to conduct training.”

Alexander Chepurnov – Leading Researcher at the Institute of Clinical and Experimental Medicine, ex-employee of Vector.

And the immune system develops various types of protection – antibodies, T-cell immunity.

EpiVacCorona was created according to the following algorithm. The smallest proteins of the coronavirus, peptides, were taken, which scientists, for some reason, considered immunologically significant. Because they are small, the idea is that the body will respond to very specific immunological stimuli, and not having a lot of protein will make the vaccine less reactogenic.

“But the immune system does not see such small proteins – in order to see it, it is necessary to plant them on something, on some kind of protein carrier that can play a useful role. They planted the internal N-protein, which is in the coronavirus, made using technological tricks – that is, they created an image where there is an internal protein that is not important for the immune response, and three fragments of the surface protein that were considered important, ”Chepurnov explains.

CoviVac is called a killed or inactivated vaccine – an old approach to vaccine development that began 250 years ago.First, scientists “develop” a coronavirus – they take a cell culture, infect it with a virus, having previously isolated it so that it matches the strain prevalent in the country as much as possible. Cell culture produces a lot of virus, they are destroyed. Then this culture is cleared of impurity proteins that appear during production, it is cleaned and a pure fraction of the virus is obtained, which is “killed”. In the old days, this was done with formalin, now there are more modern methods that allow the virus to not denature so much, but make it incapable of reproducing.

Which Russian vaccine is more effective?

It should be borne in mind that in the world about 5-7% of people are generally not able to develop immunity after vaccination. However, the probability of getting it from each of us is still high.

Sputnik V. The developers promise that the vaccine is 93% effective, in other words, seven out of a hundred people will get sick. However, the severity of the course of the disease should be significantly lower. On the Stopcoronavirus website.rf also notes that antibodies were found in 98% of the volunteers, cellular immunity was formed in all test participants. Immunity after vaccination was 1.3-1.5 times higher than after the previous illness. The developers of the drug promise that immunity from the vaccine lasts up to two years, but experts are increasingly talking about 6 months.

“Sputnik” is the vaccine about which one can say “the horse plows and does not spoil the furrows.” Yes, there are doubts about the new strains, it is clear that there are sick and seriously ill patients after vaccination, but their share is small, ”says Andrey Isaev, head of the scientific center for molecular genetic research at DNKOM.The expert added that the vaccine has proven itself in the fields, including in terms of its impact on the new strains of the Delta and Delta + coronavirus.

“My doubts about“ Sputnik ”disappeared from me personally when I saw the titers of neutralizing antibodies. Routine tests do not show, but neutralizing antibodies are visible when the serum of the sick is mixed with the virus and see if it has been neutralized. If so, how much should it be diluted so that it retains its properties. A third of the sera of the Hamaley vaccine had a high titer.The rest had less, but neutralizing antibodies were present in all cases. Quite good reviews about cellular immunity, it was investigated by my colleagues, ”emphasizes Alexander Chepurnov.

EpiVacCorone Developers guarantee one hundred percent immunological effectiveness.

Antibodies to “EpiVacCorona” are recorded only by a special test system of Rospotrebnadzor.

“As conceived by scientists, it requires the interaction of T-cells with B-cells, but the adjuvant in this vaccine (a complex of additional substances that enhances the immune response),” sharpens “it exclusively for the production of B-cell antibodies, which are not seen by conventional tests” , – the expert notes.

KoviVak – according to the data of the Center. Chumakov, the effectiveness of the vaccine exceeds 80%. An article about this, according to the developer, should be expected in August-September. People aged 60 and over are likely to need one more dose, the Chumakovites note.

“There are virus-neutralizing antibodies after KoviVac,” notes Andrey Isaev. – It is believed to provide a comprehensive immune response to all coronavirus proteins, not just the S-protein.Some experts believe that these non-core antibodies suppress the immune system, but I’m not sure if this can harm, because natural immunity is formed on the basis of all types of antibodies. ”

“The immune response is not as active as with Sputnik, since KoviVac gives antibodies to other parts of the virus, which are not so important. Maybe there are more antibodies in total, but we do not measure each term and do not know what kind of protection is the result, ”Ancha Baranova emphasizes. “Judging by civil statistics, after KoviVac, the average level of antibodies for the S-protein is still less than after Sputnik, but this information needs to be clarified.”

What are the side effects of each vaccine?

None of them have distant side effects, the past has too little time for that. But “quick reactions” each has its own.

“Sputnik” gives rise in temperature to every second vaccinated on the day of administration and the next, sometimes muscle aches. The instructions also indicate such possible reactions as nausea, dyspepsia, decreased appetite and swollen lymph nodes.

“After the introduction of the second component, the next day, it hurt terribly in the bridge of the nose and forehead, giving it to the eyes – I have never had such a headache,” says a vaccinated 25-year-old girl in one of the popular chats on Telegram.- I lay all day, the temperature fluctuated around 38, my shoulder hurt. The next day everything passed without a trace. ”

“Vaccine protein is really unpleasant for the body. According to new data from scientists, it itself has some neurotoxic properties and affects blood clotting. But when vaccinated, there is very little free S-protein in the body, especially in comparison with a natural infection. Because adenovirus produces protein in muscle cells, not in the central bloodstream. Vaccination allows you to choose from two evils not just the lesser, but much less.”- said Ancha Baranova professor at the School of Systems Biology at George Mason University

With regard to other negative consequences, the expert advised not to blame everything on the vaccine, since a person could have a whole bunch of diseases even before vaccination, including undiagnosed ones. If he has any of the systems already broken, the likelihood that the reaction to the vaccine will affect her increases.

EpiVacCorona : among the side effects in the instructions indicate pain at the injection site and a short-term increase in temperature not higher than 38.5 ° C.But in fact, there are almost no complaints, since the vaccine contains little protein.

KoviVak most commonly causes allergic reactions, drowsiness, dry eyes and minimal shoulder pain. This is exactly what those vaccinated in Telegram chats complain about:

“KoviVak” and my wife got accustomed, we are 66 years old. And after the first dose, and after the second, there were no special side effects. On the third or fifth day after the injections, there was a slight weakness, drowsiness, at normal temperature there was a slight chill, heaviness in the head, a desire to eat more and more often.By the end of the first week after the injection, all deviations from the normal state were gone. ”

Who should be vaccinated with?

As for people with disabilities, EpiVacCorona is contraindicated in people with primary immunodeficiency and malignant blood diseases. It also makes no sense to do “Sputnik” while taking medications that suppress the function of the immune system.

In the instructions for vaccines there is a warning that people with chronic liver and kidney diseases, severe endocrine system disorders, diabetes mellitus, severe diseases of the hematopoietic system, epilepsy, as well as strokes and other diseases of the central nervous system should be vaccinated with caution, diseases of the cardiovascular system, autoimmune diseases.

In the instructions for the vaccine from the Center. Gamaleas in this list also include lung diseases, asthma, atopy and eczema.

“Sputnik light – a good version for those who have been ill: it has been proven that with the introduction of the vaccine to those who have been ill, the effectiveness of the response increases.

“That is, a single vaccination of a patient who has recovered gives a stronger immune response than a double vaccination in a person who has not recovered,” Chepurnov explains. – You can get vaccinated in 6–8 months.And it would be good to monitor once every two to three months how the antibodies go down. They are of different levels and leave the body with different intensity and speed. When they decrease by 3-4 times, you need to get vaccinated immediately. ”

In general, vaccines are contraindicated in people with hypersensitivity to any of their components, a tendency to severe allergic reactions and children. However, “Sputnik” may soon begin to vaccinate pregnant women.

“According to international standards, the main cohort of the population is examined first, and only then the elderly, children, pregnant women,” explains the therapist Alexei Vodovozov.- We have already removed the restriction on the elderly, but not yet on children and pregnant women. However, among the 1.5 billion vaccinated in the world, there are many women who did not know that they were expecting a baby or suddenly became pregnant after being vaccinated. ”

According to him, pregnant women tolerate the vaccination normally, and the baby is born with antibodies that the mother passes on to him. The child also receives antibodies through milk. All over the world, restrictions on vaccination of pregnant women have long been lifted, and it has only now come to changes in the instructions in Russia – on May 28, the Minister of Health of the Russian Federation Mikhail Murashko announced that changes were being made to the instructions for vaccination against coronavirus for pregnant women.

According to preliminary data, a vaccine for minors has already been developed. It will be available from September 1-15 and will be administered nasally.

Every person in Russia today has the opportunity to show consciousness and stop the spread of coronavirus infection.

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structure and function. Organs of the human endocrine system

The nervous system in the process of regulating the internal and external work of the body resorts to various mechanisms.For example, muscle contraction is activated by the neuromuscular synapse, in which the excitatory potential is transmitted from the nerve cell to the muscle fiber. The mediator acetylcholine is the mediator between the electrical potential of the neuron and mechanical contraction. The action of the mediator is very fast and as local as possible. One outgrowth of a neuron affects only one muscle fiber, causing its immediate contraction. But what if a more systemic and long-term action is required? For example, it is energetically more beneficial to use the hormone vasopressin to maintain vascular tone.The action does not come as quickly as in the case of nervous regulation, but the effect is stronger and longer lasting. Thus, we come to the conclusion that the glandular system of internal and external secretion is a necessary mediator between the nervous system and target organs.

The endocrine system is a series of glands located at different distances from the brain. The hormonal effect is carried out according to the cascade principle: the higher glands act on the lower glands and systems in an activating way, and the lower ones, on the contrary, act on the higher ones inhibition.Thus, a system of natural negative feedback is implemented: if the pituitary gland has activated the thyroid gland, thyroid hormones will be released until their concentration in the bloodstream exceeds a certain threshold. When this threshold is reached, the pituitary gland will stop stimulating the thyroid gland. By this time, according to the endocrine system, the concentration of the hormone in the body will be sufficient for the correct course of all processes.

It follows that the correct relationship of all glands to each other and their correct regulation by the nervous system is a prerequisite for a healthy and happy life.

Some of the glands, in addition to secreting secretions directly into the bloodstream, also have excretory ducts into the gastrointestinal tract or into the external environment, which makes them simultaneously exocrine glands. Consider all the glands in the human body from top to bottom.

A small gray-red gland in the midbrain. Located in the area of ​​the quadruple. It is surrounded by a connective tissue capsule, from which trabeculae depart, dividing the gland into lobules.

Pineal gland hormones:
  • Melatonin is involved in the regulation of the sleep-wake cycle, blood pressure. Also participates in the seasonal regulation of some biorhythms. Slows down the aging process, inhibits the nervous system and the secretion of sex hormones.
  • Serotonin is also called the hormone of happiness. It is the main neurotransmitter. The level of serotonin in the body is directly related to the pain threshold. The higher the serotonin level, the higher the pain threshold.Plays a role in the regulation of the pituitary gland by the hypothalamus. Increases blood clotting and vascular permeability. It has an activating effect on the processes of inflammation and allergies. Strengthens intestinal motility and digestion. It also has an activating effect on some types of intestinal microflora. Participates in the regulation of the contractile function of the uterus and in the process of ovulation in the ovary.
  • Adrenoglomerulotropin is involved in the work of the adrenal glands.
  • Dimethyltryptamine is produced during REM sleep and borderline conditions such as life-threatening conditions, birth or death.

The hypothalamus is the central organ that regulates the work of all glands through the activation of secretion in the pituitary gland or through its own secretion of hormones. Located in the diencephalon as a group of cells.

Vasopressin, also called “antidiuretic hormone”, is secreted in the hypothalamus and regulates the tone of the blood vessels, as well as filtration in the kidneys, thus altering the volume of urine excreted.

Oxytocin is secreted in the hypothalamus, then transported to the pituitary gland. There it accumulates and is subsequently secreted. Oxytocin plays a role in the functioning of the mammary glands, has a stimulating effect on uterine contraction and regeneration by stimulating stem cell growth. It also induces feelings of satisfaction, calmness and empathy.

Located in the pituitary fossa of the sella turcica of the sphenoid bone. Divided into anterior and posterior lobes.

Hormones of the anterior pituitary gland:
  • Growth hormone or growth hormone. Acts mainly in adolescence, stimulating the growth zones in the bones, and causes growth in length. Increases protein synthesis and fat burning. Increases blood glucose levels by inhibiting insulin.
  • Lactotropic hormone regulates the functioning of the mammary glands and their growth.
  • Follicle-stimulating hormone, or FSH, stimulates the development of follicles in the ovaries and the secretion of estrogen.In the male body, it participates in the development of the testes and enhances spermatogenesis and testosterone production.
  • Luteinizing hormone works in tandem with FSH. In the male body, it stimulates the production of testosterone. In women, ovarian secretion of estrogen and ovulation at the peak of the cycle.
  • Adrenocorticotropic hormone, or ACTH. Regulates the work of the adrenal cortex, namely, the secretion of glucocorticoids (cortisol, cortisone, corticosterone) and sex hormones (androgens, estrogens, progesterone).Glucocorticoids are especially important in stressful reactions and in shock conditions, they inhibit the sensitivity of tissues to many higher hormones, thus concentrating the body’s attention on the process of getting out of a stressful situation. When the situation is life-threatening, digestion, growth and sexual function take a back seat.
  • Thyroid stimulating hormone is a triggering factor for the synthesis of thyroxine in the thyroid gland. It also indirectly affects the synthesis of triiodothyronine and thyroxine in the same place.These thyroid hormones are essential regulators of the growth and development of the body.

The gland is located on the front surface of the neck, the esophagus and trachea pass behind it, and the front is covered with thyroid cartilage. The thyroid cartilage in men is slightly more developed and forms a characteristic tubercle – the Adam’s apple, also known as the Adam’s apple. The gland consists of two lobules and an isthmus.

Thyroid hormones:
  • Thyroxine has no specificity and acts on absolutely all cells of the body.Its function is to activate metabolic processes, namely, the synthesis of RNA and proteins. Affects the heart rate and growth of the uterine lining in women.
  • Triiodothyronine is the biologically active form of the aforementioned thyroxine.
  • Calcitonin regulates the exchange of phosphorus and calcium in bones.

A gland located behind the sternum in the mediastinum. Before the onset of puberty, it grows, then undergoes a gradual reverse development, involution, and by old age it practically does not stand out against the background of the surrounding adipose tissue.In addition to the hormonal function, the maturation of T-lymphocytes, the most important immune cells, occurs in the thymus.

Thymus hormones:
  • Thymosin stimulates the immune system, participates in carbohydrate metabolism and skeletal development.
  • Thymopoietin is involved in the development of T-lymphocytes of the immune system.

The gland is located behind the stomach, separated from the stomach by the omental bursa.The inferior vena cava, the aorta, and the left renal vein pass behind the gland. Anatomically, the head of the gland, body and tail are distinguished. The loop of the duodenum bends around the head of the gland in front. In the area of ​​contact of the gland with the intestine, the Wirsung duct passes through which the pancreas is secreted, that is, its exocrine function. Often there is also an additional duct as a fallback.

The main volume of the gland performs an exocrine function and is represented by a system of branched collecting ducts.The endocrine function is performed by pancreatic islets, or islets of Langerhans, located diffusely. Most of them are in the tail of the gland.

Pancreatic hormones:
  • Glucagon accelerates the breakdown of glycogen in the liver without affecting glycogen in skeletal muscle. Due to this mechanism, the blood glucose level is maintained at the proper level. It also increases the synthesis of insulin, which is required for glucose metabolism.Increases heart rate and strength. It is an important component of the “fight or flight” system, increasing the amount of resources and their availability for organs and tissues.
  • Insulin has a number of functions, the main of which is the breakdown of glucose with the release of energy, as well as the storage of excess glucose in the form of glycogen in the liver and muscles. Insulin also inhibits the breakdown of glycogen and fats. In case of violation of insulin synthesis, the development of the disease is possible diabetes mellitus.
  • Somatostatin has a pronounced inhibitory effect on the hypothalamus and pituitary gland, inhibiting the production of somatotropic and thyroid-stimulating hormones. It also lowers the secretion of many other substances and hormones, for example, insulin, glucagon, insulin-like growth factor (IGF-1).
  • Pancreatic polypeptide decreases pancreatic external secretion and increases gastric acid secretion.
  • Ghrelin is associated with hunger and satiety. The amount of fat in the body is directly related to this regulation.

Paired organs of a pyramidal shape, adjacent to the upper pole of each kidney, are connected with the kidneys by common blood vessels. Divided into cortex and medulla. In general, they play an important role in the process of adaptation to stressful conditions for the body.

The adrenal cortex produces hormones that increase the body’s resistance, as well as hormones that regulate water-salt metabolism. These hormones are called corticosteroids (cortex – cortex).The cortex is divided into three sections: the glomerular zone, the bundle zone and the reticular zone.

Glomerular hormones, mineralocorticoids:
  • Aldosterone regulates the content of K + and Na + ions in the bloodstream and tissues, thus affecting the amount of water in the body and the ratio of the amount of water between tissues and blood vessels.
  • Corticosterone, like aldosterone, works in the field of salt metabolism, but its role in the human body is small.For example, in mice, corticosterone is the main mineralocorticoid.
  • Deoxycorticosterone is also inactive and similar in action to the above.
Hormones of the bundle zone, glucocorticoids:
  • Cortisol is secreted by order of the pituitary gland. Regulates carbohydrate metabolism and participates in stress reactions. Interestingly, the secretion of cortisol is clearly tied to the circadian rhythm: the maximum level is in the morning, the minimum is in the evening. There is also a dependence on the stage of the menstrual cycle in women.Acts mainly on the liver, causing there an increase in the formation of glucose and its storage in the form of glycogen. This process is intended to preserve the energy resource and store it for future use.
  • Cortisone stimulates the synthesis of carbohydrates from proteins and increases resistance to stress.
Mesh hormones, sex hormones:
  • Androgens, male sex hormones, are precursors
  • Estrogen, female hormones. Unlike the sex hormones from the gonads, the adrenal sex hormones are active before puberty and after the gonads have matured.They take part in the development of secondary sexual characteristics (facial hair and coarsening of the timbre in men, the growth of mammary glands and the formation of a special silhouette in women). A lack of these sex hormones leads to hair loss, an excess leads to the appearance of signs of the opposite sex.
Adrenal medulla produces hormones:
  • Adrenaline, which increases the strength and heart rate, increases blood pressure, participates in carbohydrate metabolism, enhancing the breakdown of glycogen to glucose, dilates the pupil.
  • Norepinephrine is a precursor of adrenaline, the action is similar to adrenaline.

Paired glands in which the formation of germ cells occurs, as well as the production of sex hormones. Male and female gonads differ in structure and location.

Males are located in a multi-layered fold of skin called the scrotum, located in the groin. This location was not chosen by chance, since normal sperm maturation requires temperatures below 37 degrees.The testicles have a lobular structure, from the periphery to the center are convoluted spermatic cords, as they move from the periphery to the center, the maturation of spermatozoa occurs.

In the female body, the sex glands are located in the abdominal cavity on the sides of the uterus. They contain follicles at different stages of development. During about one lunar month, the most developed follicle comes out closer to the surface, breaks through, releasing the egg, after which the follicle undergoes a reverse development, while releasing hormones.

Male sex hormones, androgens, are the strongest steroid hormones. Accelerate the breakdown of glucose with the release of energy. Increases muscle mass and decreases fat. An increased level of androgens increases libido in both sexes, and also contributes to the development of male secondary sexual characteristics: coarsening of the voice, skeletal changes, facial hair growth, etc.

Female sex hormones, estrogens, are also anabolic steroids.They are mainly responsible for the development of the female genital organs, including the mammary glands, the formation of female secondary sexual characteristics. It is also discovered that estrogens have anti-atherosclerotic action, which is associated with a more rare manifestation of atherosclerosis in women.

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