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Human body glands and their function: The Endocrine System and Glands of the Human Body: Function and Disorders

Pituitary Gland Disorder Causes & Treatments

What Is Hypopituitarism?

Hypopituitarism is a condition in which your pituitary gland (a small gland at the base of the brain) doesn’t make one or more of its hormones, or not enough of them. This condition may be the result of disease in the pituitary or hypothalamus (a part of the brain that contains hormones that control the pituitary gland). When there is low or no production of all the pituitary hormones, the condition is called panhypopituitarism. This condition may affect both children or adults.

The pituitary gland sends signals to other glands, for example the thyroid gland, to make hormones, such as thyroid hormone. The hormones made by the pituitary gland and other glands have a big impact on bodily functions, such as growth, reproduction, blood pressure, and metabolism. When one or more of these hormones isn’t produced as it should be, your body’s normal functions can be affected. Some of the problems with hormones, such as with cortisol or thyroid hormone, may need immediate treatment. Others aren’t life-threatening problems.

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The pituitary gland makes several hormones. Some important ones include:

  • Adrenocorticotropic hormone (ACTH) is a hormone that stimulates the adrenal glands (glands located above or on top of the kidneys that produce hormones). ACTH triggers the adrenal glands to release a hormone called cortisol, which regulates metabolism and blood pressure.
  • Thyroid-stimulating hormone (TSH) is a hormone that stimulates production and secretion of thyroid hormones from the thyroid gland (a gland in the hormone system). Thyroid hormone regulates the body’s metabolism and is important in growth and development.
  • Follicle-stimulating hormone (FSH) and luteinizing hormone (LH) are hormones that control sexual function in males and females. LH and FSH are also known as gonadotropins. They act on the ovaries or testes to stimulate sex hormone production- estrogen from ovaries and testosterone from testes.
  • Growth hormone (GH) is a hormone that stimulates normal growth of bones and tissues.
  • Prolactin is a hormone that stimulates milk production and female breast growth.
  • Antidiuretic hormone (ADH) is a hormone that controls water loss by the kidneys.
  • Oxytocin tells a woman’s uterus to contract during childbirth and signals milk to release so the baby can feed. It also helps sperm move in men. Oxytocin also plays a part in the parent-child bond, sexual arousal, and feelings of trust.

In hypopituitarism, one or more of these pituitary hormones is missing. The lack of hormone results in a loss of function of the gland or organ that it controls.

Hypopituitarism Causes

A loss of function in or damage to your pituitary gland or hypothalamus results in low or absent hormones. You might have this because of:

  • Tumors
  • Radiation
  • Surgery
  • Infections such as meningitis, or various other conditions.
  • Head injuries
  • Stroke or bleeding into the brain
  • Medications
  • Inflammation caused by abnormal immune system response
  • Severe loss of blood during childbirth
  • Genetic mutation
  • Sarcoidosis
  • Tuberculosis

In some cases, the cause is unknown.

Hypopituitarism Symptoms

Some people may have no symptoms or a gradual onset of symptoms. In other people, the symptoms may be sudden and dramatic. The symptoms depend on the cause, how fast they come on, and the hormone that is involved.

  • ACTH deficiency: Symptoms include fatigue, low blood pressure, weight loss, weakness, depression, nausea, or vomiting.
  • TSH deficiency: Symptoms include constipation, weight gain, sensitivity to cold, decreased energy, and muscle weakness or aching.
  • FSH and LH deficiency: In women, symptoms include irregular or stopped menstrual periods and infertility. In men, symptoms include loss of body and facial hair, weakness, lack of interest in sexual activity, erectile dysfunction, and infertility.
  • GH deficiency: In children, symptoms include short height, fat around the waist and in the face, and poor overall growth. In adults, symptoms include low energy, decreased strength and exercise tolerance, weight gain, decreased muscle mass, and feelings of anxiety or depression.
  • Prolactin deficiency: In women, symptoms include lack of milk production. No symptoms are seen in men.
  • ADH deficiency: Symptoms include increased thirst and urination.
  • Oxytocin hormone deficiency: Women may have a hard time breastfeeding because of difficulty with milk letdown. Low oxytocin may also trigger symptoms of depression.

Call the doctor or health care practitioner if any of the above symptoms develop.

Hypopituitarism Diagnosis

The doctor or health care practitioner may do blood tests to determine which hormone level is low and to rule out other causes. Test you may have include:

  • ACTH (Cortrosyn) stimulation test
  • TSH and thyroxine test
  • FSH and LH and either estradiol or testosterone (whichever is appropriate for the patient)
  • Prolactin test
  • GH stimulation test
  • Stimulation or suppression  testing (tests that check your hormone levels after you take certain medications)
  • Vision tests

You may get an MRI or CT scan of the pituitary gland may to find whether a tumor is present.

In children, X-rays of the hands may be taken to determine if bones are growing normally.

Hypopituitarism Treatment

Medical treatment consists of hormone replacement therapy and treatment of the underlying cause.

Medications

Drugs used to treat hypopituitarism replace the hormone of which you don’t have enough:

  • Glucocorticoids (for example, hydrocortisone) are used to treat adrenal insufficiency resulting from ACTH deficiency.
  • Thyroid hormone replacement therapy is used for hypothyroidism (a condition in which thyroid production is low). Drugs, such as levothyroxine (for example, Synthroid, Levoxyl), may be used. In the drug’s active form, it influences growth and development of tissues.
  • Sex hormone deficiency is treated with sex-appropriate hormones such as testosterone or estrogen.
  • Growth hormone (GH) replacement therapy is used for children as appropriate. Growth hormone stimulates linear growth and growth of skeletal muscle and organs. GH therapy may also be used in adults, but it will not make them grow taller. Examples include somapacitan-beco (Sogroya) or somatropin (Humatrope or Genotropin).
  • Fertility hormones such as gonadotropin can help jumpstart ovulation or sperm production if you’re dealing with infertility.

Surgery

If a tumor is involved, you may need surgery, depending on its type and location.

Hypopituitarism Outlook

If hormone replacement therapy works, the prognosis is good. Complications are often related to the underlying disease.

Checkups with the doctor or health care practitioner are important. The doctor may need to adjust the dose of hormone replacement therapy.

10 Ways to Stop Stress Now

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Glands and hormones in human body

In the human body, the endocrine system consists of a network of glands and secrete hormones to regulate the functions of the body including growth and metabolism. When glands produce an incorrect amount of hormones, it results in endocrine diseases. Therefore, the endocrine system is a network of glands that secrete hormones to help the body to function properly. Let us tell you that hormones coordinate a range of bodily functions. 

Hormone

There are some special tissues in our body called endocrine glands that secrete chemical substances called hormones. These hormones help in coordinating the activities of living organisms and their growth. Following are the characteristics of hormones:

  • Hormones are secreted by endocrine glands in small amounts.
  • Hormones are secreted directly into blood and travel throughout the body through the blood circulatory system.
  • Hormones have their effect on the sites different from where they are made.
  • Hormones act on specific tissues or organs.

Endocrine Glands

 A gland secretes a specific substance in the body. There are two types of glands. They are:

i) Exocrine glands

ii) Endocrine glands

Exocrine glands are the glands that secrete their product into a duct. For example, the salivary gland secretes the saliva into the salivary duct.

Endocrine glands are the glands that secrete their product directly into the blood. There are no ducts in endocrine glands. The chemical substance secreted by endocrine glands is called hormone. These hormones travel through the blood and act on the concerned body part. Hormones are a kind of chemical messengers.

There are glands that have both exocrine and endocrine functions. Pancreas, testes, and ovaries perform both exocrine and endocrine functions. For example, the pancreas acts as an endocrine gland and secretes insulin. It also acts as an exocrine gland and secretes pancreatic juice into the pancreatic duct.

The Endocrine System

                     

    Source: www.embryology.med.unsw.edu.au

The endocrine system also helps in coordinating the activities of our body. The endocrine glands present in our body are the pineal gland, hypothalamus gland, pituitary gland, thyroid gland, parathyroid gland, thymus, pancreas, adrenal gland, testes, and ovaries. The nervous system controls the working of endocrine glands. The hormones act as a messenger between the nervous system and organs of the body.

Hypothalamus and pituitary gland are main centres for the coordination of the nervous system and endocrine system. The hypothalamus helps in collecting information from the regions of the brain and from blood vessels passing through it. The information is then passed on to the pituitary gland which by its secretions regulates the activities of all other endocrine glands. In the human body, hormones help in growth, metabolic activities and reproduction.

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Hypothalamus

This gland is present in the brain and produces releasing hormone and inhibitory hormone. Hypothalamus regulates the secretions of hormones from the pituitary gland.

Pituitary Gland

This gland is present just below the brain and secretes a number of hormones. One of the hormones secreted by the pituitary gland is growth hormone. This growth hormone controls the development of bones and muscles. A person having a deficiency of growth hormone becomes very short and the person having too much growth hormone becomes very tall.

Thyroid Gland

The thyroid gland is attached to the windpipe and makes a hormone called thyroxin which contains iodine. The function of this hormone is to control the rate of metabolism of carbohydrates, fats, and proteins in the body. The deficiency of iodine in the diet can cause a deficiency of thyroxin hormone in the body. This causes a disease called a goitre.

Parathyroid Gland

There are four parathyroid glands that are embedded in the thyroid gland. The parathyroid gland secretes a hormone called parathormone which helps to regulate calcium and phosphate levels in the blood.

Thymus Gland

This gland is present in the lower part of the neck and upper part of the chest. Thymus gland secretes thymus hormone which helps in the development of the immune system of the body.

Pancreas

This hormone is present just below the stomach and secretes a hormone called insulin. The function of insulin is to lower the blood sugar level. The deficiency of insulin hormone causes a disease called diabetes. A person having diabetes has large quantities of sugar in the blood.

Adrenal Glands

Adrenal glands are located at the top of two kidneys. These glands secrete an adrenal hormone that regulates heart rate, breathing rate, blood pressure, and carbohydrate metabolism. This hormone is secreted in large amounts when the person is excited or frightened. This gland is also called glands of emergency.

Testes

This gland is present only in males and makes male sex hormones called testosterone. The testosterone controls the development of male sex organs and male features such as deeper voice, mustache, beard, etc.

Ovaries

This gland is present in females only and make a female sex hormone called oestrogen and progesterone. Oestrogen helps in controlling the development of female sex organs and female features such as feminine voice, soft skin, and mammary glands. The progesterone hormone controls the uterus changes in the menstrual cycle. It helps in the maintenance of pregnancy.

Feedback Mechanism 

The excess or deficiency of hormones has a harmful effect on our bodies. So in order to control and regulate the production and release of hormones in the body, there is a feedback mechanism that is in-built in our body.


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Endocrine glands and their hormones

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3-minute read

The hormonal system (called the endocrine system in medical terminology) has various glands that release different hormones.

Hormones are like the body’s communication system. They take messages from one part of the body (the gland) to tell another part of the body (the target cell) to do something important. The endocrine glands influence reproduction, metabolism, growth and many other functions.

Below is a list of the main glands (see diagram for their location), some of the hormones they produce and what effects they have on the body.

Hypothalamus: an area in the base of the brain that links the brain to the hormonal system.

The endocrine system.

  • major hormones — anti-diuretic hormone (ADH), oxytocin, dopamine, corticotrophin releasing hormone, thyrotrophin releasing hormone (TRH), gonadotrophin releasing hormone (GnRH), growth hormone releasing hormone (GHRH) and somatostatin
  • influences — they hypothalamus links the hormonal and nervous systems. Its hormones keep the body stable. They influence sleep rhythms, alertness, appetite, body weight, thirst, blood pressure, heart rate, sex drive, learning, memory, mood and how the body responds to being sick

Pituitary gland: a kidney bean-shaped gland in the base of the brain.

  • major hormones — luteinising hormone (LH), follicle-stimulating hormone (FSH), prolactin, growth hormone, thyroid stimulating hormone (TSH), adrenocorticotrophic hormone (ACTH)
  • influences — the pituitary gland helps control other glands and makes hormones that control blood pressure, blood sugar levels, response to stress, menstruation, sperm production, bone growth, muscle mass, contractions during childbirth, making breastmilk and bonding between mother and baby

Other glands

Pineal gland: a small gland near the centre of the brain.

Thyroid gland: a small gland in the front of the neck, wrapping around the windpipe.

  • major hormones — tri-iodothyronine (T3), thyroxine (T4), calcitonin
  • influences — metabolism, bone growth, energy levels, body temperature, how the cells use oxygen, heart rate, blood flow, calcium levels, vitamin metabolism, brain development in babies and children, and reproduction

Parathyroid glands: four small glands in the neck behind the thyroid gland.

  • major hormones — parathyroid hormone (PTH)
  • influences — regulating calcium levels in the blood

Adrenal glands: 2 glands that sit above the kidneys on each side of the body.

  • major hormones — adrenaline, cortisol, aldosterone, DHEA, testosterone
  • influences — stress response and blood pressure/salt and water control, blood sugar levels, energy, development of sex organs, heart rate, attention, inflammation, development of the fetus

The parathyroid glands.

Pancreas: a long gland behind the stomach, under the liver.

  • major hormones — insulin, glucagon, somatostatin, vasoactive intestinal peptide (VIP)
  • influences — blood sugar control

Ovaries (females only): 2 glands found on each side of the uterus in the pelvis.

  • major hormones — oestrogen, progesterone, testosterone, anti-mullerian hormone (AMH), Inhibin A and Inhibin B
  • influences — female characteristics, storing and releasing eggs

Testes (males only): 2 glands in the scrotum, behind the penis.

  • major hormones — testosterone, anti-mullerian hormone (AMH), estradiol, inhibin B
  • influences — male characteristics, sperm production

Find out more about the hormonal system.

Learn more here about the development and quality assurance of healthdirect content.

Last reviewed: November 2020

11.4 Endocrine System – Concepts of Biology – 1st Canadian Edition

Learning Objectives

By the end of this section, you will be able to:

  • List the different types of hormones and explain their roles in maintaining homeostasis
  • Explain how hormones work
  • Explain how hormone production is regulated
  • Describe the role of different glands in the endocrine system
  • Explain how the different glands work together to maintain homeostasis

The endocrine system produces hormones that function to control and regulate many different body processes. The endocrine system coordinates with the nervous system to control the functions of the other organ systems. Cells of the endocrine system produce molecular signals called hormones. These cells may compose endocrine glands, may be tissues or may be located in organs or tissues that have functions in addition to hormone production. Hormones circulate throughout the body and stimulate a response in cells that have receptors able to bind with them. The changes brought about in the receiving cells affect the functioning of the organ system to which they belong. Many of the hormones are secreted in response to signals from the nervous system, thus the two systems act in concert to effect changes in the body.

Maintaining homeostasis within the body requires the coordination of many different systems and organs. One mechanism of communication between neighboring cells, and between cells and tissues in distant parts of the body, occurs through the release of chemicals called hormones. Hormones are released into body fluids, usually blood, which carries them to their target cells where they elicit a response. The cells that secrete hormones are often located in specific organs, called endocrine glands, and the cells, tissues, and organs that secrete hormones make up the endocrine system. Examples of endocrine organs include the pancreas, which produces the hormones insulin and glucagon to regulate blood-glucose levels, the adrenal glands, which produce hormones such as epinephrine and norepinephrine that regulate responses to stress, and the thyroid gland, which produces thyroid hormones that regulate metabolic rates.

The endocrine glands differ from the exocrine glands. Exocrine glands secrete chemicals through ducts that lead outside the gland (not to the blood). For example, sweat produced by sweat glands is released into ducts that carry sweat to the surface of the skin. The pancreas has both endocrine and exocrine functions because besides releasing hormones into the blood. It also produces digestive juices, which are carried by ducts into the small intestine.

Endocrinologist

An endocrinologist is a medical doctor who specializes in treating endocrine disorders. An endocrine surgeon specializes in the surgical treatment of endocrine diseases and glands. Some of the diseases that are managed by endocrinologists include disorders of the pancreas (diabetes mellitus), disorders of the pituitary (gigantism, acromegaly, and pituitary dwarfism), disorders of the thyroid gland (goiter and Graves’ disease), and disorders of the adrenal glands (Cushing’s disease and Addison’s disease).

Endocrinologists are required to assess patients and diagnose endocrine disorders through extensive use of laboratory tests. Many endocrine diseases are diagnosed using tests that stimulate or suppress endocrine organ functioning. Blood samples are then drawn to determine the effect of stimulating or suppressing an endocrine organ on the production of hormones. For example, to diagnose diabetes mellitus, patients are required to fast for 12 to 24 hours. They are then given a sugary drink, which stimulates the pancreas to produce insulin to decrease blood-glucose levels. A blood sample is taken one to two hours after the sugar drink is consumed. If the pancreas is functioning properly, the blood-glucose level will be within a normal range. Another example is the A1C test, which can be performed during blood screening. The A1C test measures average blood-glucose levels over the past two to three months. The A1C test is an indicator of how well blood glucose is being managed over a long time.

Once a disease such as diabetes has been diagnosed, endocrinologists can prescribe lifestyle changes and medications to treat the disease. Some cases of diabetes mellitus can be managed by exercise, weight loss, and a healthy diet; in other cases, medications may be required to enhance insulin’s production or effect. If the disease cannot be controlled by these means, the endocrinologist may prescribe insulin injections.

In addition to clinical practice, endocrinologists may also be involved in primary research and development activities. For example, ongoing islet transplant research is investigating how healthy pancreas islet cells may be transplanted into diabetic patients. Successful islet transplants may allow patients to stop taking insulin injections.

Hormones cause changes in target cells by binding to specific cell-surface or intracellular hormone receptors, molecules embedded in the cell membrane or floating in the cytoplasm with a binding site that matches a binding site on the hormone molecule. In this way, even though hormones circulate throughout the body and come into contact with many different cell types, they only affect cells that possess the necessary receptors. Receptors for a specific hormone may be found on or in many different cells or may be limited to a small number of specialized cells. For example, thyroid hormones act on many different tissue types, stimulating metabolic activity throughout the body. Cells can have many receptors for the same hormone but often also possess receptors for different types of hormones. The number of receptors that respond to a hormone determines the cell’s sensitivity to that hormone, and the resulting cellular response. Additionally, the number of receptors available to respond to a hormone can change over time, resulting in increased or decreased cell sensitivity. In up-regulation, the number of receptors increases in response to rising hormone levels, making the cell more sensitive to the hormone and allowing for more cellular activity. When the number of receptors decreases in response to rising hormone levels, called down-regulation, cellular activity is reduced.

The endocrine glands secrete hormones into the surrounding interstitial fluid; those hormones then diffuse into blood and are carried to various organs and tissues within the body. The endocrine glands include the pituitary, thyroid, parathyroid, adrenal glands, gonads, pineal, and pancreas.

The pituitary gland, sometimes called the hypophysis, is located at the base of the brain (Figure 11.23 a). It is attached to the hypothalamus. The posterior lobe stores and releases oxytocin and antidiuretic hormone produced by the hypothalamus. The anterior lobe responds to hormones produced by the hypothalamus by producing its own hormones, most of which regulate other hormone-producing glands.

Figure 11.23 (a) The pituitary gland sits at the base of the brain, just above the brain stem. (b) The parathyroid glands are located on the posterior of the thyroid gland. (c) The adrenal glands are on top of the kidneys. d) The pancreas is found between the stomach and the small intestine. (credit: modification of work by NCI, NIH)

The anterior pituitary produces six hormones: growth hormone, prolactin, thyroid-stimulating hormone, adrenocorticotropic hormone, follicle-stimulating hormone, and luteinizing hormone. Growth hormone stimulates cellular activities like protein synthesis that promote growth. Prolactin stimulates the production of milk by the mammary glands. The other hormones produced by the anterior pituitary regulate the production of hormones by other endocrine tissues (Table 11.1). The posterior pituitary is significantly different in structure from the anterior pituitary. It is a part of the brain, extending down from the hypothalamus, and contains mostly nerve fibers that extend from the hypothalamus to the posterior pituitary.

The thyroid gland is located in the neck, just below the larynx and in front of the trachea (Figure 11.23 b). It is a butterfly-shaped gland with two lobes that are connected. The thyroid follicle cells synthesize the hormone thyroxine, which is also known as T4 because it contains four atoms of iodine, and triiodothyronine, also known as T3 because it contains three atoms of iodine. T3 and T4 are released by the thyroid in response to thyroid-stimulating hormone produced by the anterior pituitary, and both T3 and T4 have the effect of stimulating metabolic activity in the body and increasing energy use. A third hormone, calcitonin, is also produced by the thyroid. Calcitonin is released in response to rising calcium ion concentrations in the blood and has the effect of reducing those levels.

Most people have four parathyroid glands; however, the number can vary from two to six. These glands are located on the posterior surface of the thyroid gland (Figure 11.23 b).

The parathyroid glands produce parathyroid hormone. Parathyroid hormone increases blood calcium concentrations when calcium ion levels fall below normal.

The adrenal glands are located on top of each kidney (Figure 11.23 c). The adrenal glands consist of an outer adrenal cortex and an inner adrenal medulla. These regions secrete different hormones.

The adrenal cortex produces mineralocorticoids, glucocorticoids, and androgens. The main mineralocorticoid is aldosterone, which regulates the concentration of ions in urine, sweat, and saliva. Aldosterone release from the adrenal cortex is stimulated by a decrease in blood concentrations of sodium ions, blood volume, or blood pressure, or by an increase in blood potassium levels. The glucocorticoids maintain proper blood-glucose levels between meals. They also control a response to stress by increasing glucose synthesis from fats and proteins and interact with epinephrine to cause vasoconstriction. Androgens are sex hormones that are produced in small amounts by the adrenal cortex. They do not normally affect sexual characteristics and may supplement sex hormones released from the gonads. The adrenal medulla contains two types of secretory cells: one that produces epinephrine (adrenaline) and another that produces norepinephrine (noradrenaline). Epinephrine and norepinephrine cause immediate, short-term changes in response to stressors, inducing the so-called fight-or-flight response. The responses include increased heart rate, breathing rate, cardiac muscle contractions, and blood-glucose levels. They also accelerate the breakdown of glucose in skeletal muscles and stored fats in adipose tissue, and redirect blood flow toward skeletal muscles and away from skin and viscera. The release of epinephrine and norepinephrine is stimulated by neural impulses from the sympathetic nervous system that originate from the hypothalamus.

The pancreas is an elongate organ located between the stomach and the proximal portion of the small intestine (Figure 11.23 d). It contains both exocrine cells that excrete digestive enzymes and endocrine cells that release hormones.

The endocrine cells of the pancreas form clusters called pancreatic islets or the islets of Langerhans. Among the cell types in each pancreatic islet are the alpha cells, which produce the hormone glucagon, and the beta cells, which produce the hormone insulin. These hormones regulate blood-glucose levels. Alpha cells release glucagon as blood-glucose levels decline. When blood-glucose levels rise, beta cells release insulin. Glucagon causes the release of glucose to the blood from the liver, and insulin facilitates the uptake of glucose by the body’s cells.

The gonads—the male testes and female ovaries—produce steroid hormones. The testes produce androgens, testosterone being the most prominent, which allow for the development of secondary sex characteristics and the production of sperm cells. The ovaries produce estrogen and progesterone, which cause secondary sex characteristics, regulate production of eggs, control pregnancy, and prepare the body for childbirth.

There are several organs whose primary functions are non-endocrine but that also possess endocrine functions. These include the heart, kidneys, intestines, thymus, and adipose tissue. The heart has endocrine cells in the walls of the atria that release a hormone in response to increased blood volume. It causes a reduction in blood volume and blood pressure, and reduces the concentration of Na+ in the blood.

The gastrointestinal tract produces several hormones that aid in digestion. The endocrine cells are located in the mucosa of the GI tract throughout the stomach and small intestine. They trigger the release of gastric juices, which help to break down and digest food in the GI tract.

The kidneys also possess endocrine function. Two of these hormones regulate ion concentrations and blood volume or pressure. Erythropoietin (EPO) is released by kidneys in response to low oxygen levels. EPO triggers the formation of red blood cells in the bone marrow. EPO has been used by athletes to improve performance. But EPO doping has its risks, since it thickens the blood and increases strain on the heart; it also increases the risk of blood clots and therefore heart attacks and stroke.

The thymus is found behind the sternum. The thymus produces hormones referred to as thymosins, which contribute to the development of the immune response in infants. Adipose tissue, or fat tissue, produces the hormone leptin in response to food intake. Leptin produces a feeling of satiety after eating, reducing the urge for further eating.

Table 11.1 Endocrine Glands and Their Associated Hormones
Endocrine Gland Associated Hormones Effect
Pituitary (anterior) growth hormone promotes growth of body tissues
prolactin promotes milk production
thyroid-stimulating hormone stimulates thyroid hormone release
adrenocorticotropic hormone stimulates hormone release by adrenal cortex
follicle-stimulating hormone stimulates gamete production
luteinizing hormone stimulates androgen production by gonads in males; stimulates ovulation and production of estrogen and progesterone in females
Pituitary (posterior) antidiuretic hormone stimulates water reabsorption by kidneys
oxytocin stimulates uterine contractions during childbirth
Thyroid thyroxine, triiodothyronine stimulate metabolism
calcitonin reduces blood Ca2+ levels
Parathyroid parathyroid hormone increases blood Ca2+ levels
Adrenal (cortex) aldosterone increases blood Na+ levels
cortisol, corticosterone, cortisone increase blood-glucose levels
Adrenal (medulla) epinephrine, norepinephrine stimulate fight-or-flight response
Pancreas insulin reduces blood-glucose levels
glucagon increases blood-glucose levels

Hormone production and release are primarily controlled by negative feedback, as described in the discussion on homeostasis. In this way, the concentration of hormones in blood is maintained within a narrow range. For example, the anterior pituitary signals the thyroid to release thyroid hormones. Increasing levels of these hormones in the blood then give feedback to the hypothalamus and anterior pituitary to inhibit further signaling to the thyroid gland (Figure 11.24).

 Figure 11.24 The anterior pituitary stimulates the thyroid gland to release thyroid hormones T3 and T4. Increasing levels of these hormones in the blood result in feedback to the hypothalamus and anterior pituitary to inhibit further signaling to the thyroid gland. (credit: modification of work by Mikael Häggström)

 

Section Summary

Hormones cause cellular changes by binding to receptors on or in target cells. The number of receptors on a target cell can increase or decrease in response to hormone activity.

Hormone levels are primarily controlled through negative feedback, in which rising levels of a hormone inhibit its further release.

The pituitary gland is located at the base of the brain. The anterior pituitary receives signals from the hypothalamus and produces six hormones. The posterior pituitary is an extension of the brain and releases hormones (antidiuretic hormone and oxytocin) produced by the hypothalamus. The thyroid gland is located in the neck and is composed of two lobes. The thyroid produces the hormones thyroxine and triiodothyronine. The thyroid also produces calcitonin. The parathyroid glands lie on the posterior surface of the thyroid gland and produce parathyroid hormone.

The adrenal glands are located on top of the kidneys and consist of the adrenal cortex and adrenal medulla. The adrenal cortex produces the corticosteroids, glucocorticoids and mineralocorticoids. The adrenal medulla is the inner part of the adrenal gland and produces epinephrine and norepinephrine.

The pancreas lies in the abdomen between the stomach and the small intestine. Clusters of endocrine cells in the pancreas form the islets of Langerhans, which contain alpha cells that release glucagon and beta cells that release insulin. Some organs possess endocrine activity as a secondary function but have another primary function. The heart produces the hormone atrial natriuretic peptide, which functions to reduce blood volume, pressure, and Na+ concentration. The gastrointestinal tract produces various hormones that aid in digestion. The kidneys produce erythropoietin. The thymus produces hormones that aid in the development of the immune system. The gonads produce steroid hormones, including testosterone in males and estrogen and progesterone in females. Adipose tissue produces leptin, which promotes satiety signals in the brain.

Glossary

adrenal gland: the endocrine gland associated with the kidneys

down-regulation: a decrease in the number of hormone receptors in response to increased hormone levels

endocrine gland: the gland that secretes hormones into the surrounding interstitial fluid, which then diffuse into blood and are carried to various organs and tissues within the body

exocrine gland: the gland that secretes chemicals through ducts that lead to skin surfaces, body cavities, and organ cavities.

hormone: a chemical released by cells in one area of the body that affects cells in other parts of the body

intracellular hormone receptor: a hormone receptor in the cytoplasm or nucleus of a cell

pancreas: the organ located between the stomach and the small intestine that contains exocrine and endocrine cells

parathyroid gland: the gland located on the surface of the thyroid that produces parathyroid hormone

pituitary gland: the endocrine gland located at the base of the brain composed of an anterior and posterior region; also called hypophysis

thymus: the gland located behind the sternum that produces thymosin hormones that contribute to the development of the immune system

thyroid gland: an endocrine gland located in the neck that produces thyroid hormones thyroxine and triiodothyronine

up-regulation: an increase in the number of hormone receptors in response to increased hormone levels

Discover the Anatomy and Function of Glands

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Anatomy of the Endocrine System

Hypothalamus

The hypothalamus is a part of the brain located superior and anterior to the brain stem and inferior to the thalamus. It serves many different functions in the nervous system, and is also responsible for the direct control of the endocrine system through the pituitary gland. The hypothalamus contains special cells called neurosecretory cells—neurons that secrete hormones:

  • Thyrotropin-releasing hormone (TRH)
  • Growth hormone-releasing hormone (GHRH)
  • Growth hormone-inhibiting hormone (GHIH)
  • Gonadotropin-releasing hormone (GnRH)
  • Corticotropin-releasing hormone (CRH)
  • Oxytocin
  • Antidiuretic hormone (ADH)

All of the releasing and inhibiting hormones affect the function of the anterior pituitary gland. TRH stimulates the anterior pituitary gland to release thyroid-stimulating hormone. GHRH and GHIH work to regulate the release of growth hormone—GHRH stimulates growth hormone release, GHIH inhibits its release. GnRH stimulates the release of follicle stimulating hormone and luteinizing hormone while CRH stimulates the release of adrenocorticotropic hormone. The last two hormones—oxytocin and antidiuretic hormone—are produced by the hypothalamus and transported to the posterior pituitary, where they are stored and later released.

Pituitary Gland

The pituitary gland, also known as the hypophysis, is a small pea-sized lump of tissue connected to the inferior portion of the hypothalamus of the brain. Many blood vessels surround the pituitary gland to carry the hormones it releases throughout the body. Situated in a small depression in the sphenoid bone called the sella turcica, the pituitary gland is actually made of 2 completely separate structures: the posterior and anterior pituitary glands.

Posterior Pituitary

The posterior pituitary gland is actually not glandular tissue at all, but nervous tissue instead. The posterior pituitary is a small extension of the hypothalamus through which the axons of some of the neurosecretory cells of the hypothalamus extend. These neurosecretory cells create 2 hormones in the hypothalamus that are stored and released by the posterior pituitary:

  • Oxytocin triggers uterine contractions during childbirth and the release of milk during breastfeeding.
  • Antidiuretic hormone (ADH) prevents water loss in the body by increasing the re-uptake of water in the kidneys and reducing blood flow to sweat glands.
Anterior Pituitary

The anterior pituitary gland is the true glandular part of the pituitary gland. The function of the anterior pituitary gland is controlled by the releasing and inhibiting hormones of the hypothalamus. The anterior pituitary produces 6 important hormones:

  • Thyroid stimulating hormone (TSH), as its name suggests, is a tropic hormone responsible for the stimulation of the thyroid gland.
  • Adrenocorticotropic hormone (ACTH) stimulates the adrenal cortex, the outer part of the adrenal gland, to produce its hormones.
  • Follicle stimulating hormone (FSH) stimulates the follicle cells of the gonads to produce gametes—ova in females and sperm in males.
  • Luteinizing hormone (LH) stimulates the gonads to produce the sex hormones—estrogens in females and testosterone in males.
  • Human growth hormone (HGH) affects many target cells throughout the body by stimulating their growth, repair, and reproduction.
  • Prolactin (PRL) has many effects on the body, chief of which is that it stimulates the mammary glands of the breast to produce milk.

Pineal Gland

The pineal gland is a small pinecone-shaped mass of glandular tissue found just posterior to the thalamus of the brain. The pineal gland produces the hormone melatonin that helps to regulate the human sleep-wake cycle known as the circadian rhythm. The activity of the pineal gland is inhibited by stimulation from the photoreceptors of the retina. This light sensitivity causes melatonin to be produced only in low light or darkness. Increased melatonin production causes humans to feel drowsy at nighttime when the pineal gland is active.

Thyroid Gland

The thyroid gland is a butterfly-shaped gland located at the base of the neck and wrapped around the lateral sides of the trachea. The thyroid gland produces 3 major hormones: 

  • Calcitonin
  • Triiodothyronine (T3)
  • Thyroxine (T4)

Calcitonin is released when calcium ion levels in the blood rise above a certain set point. Calcitonin functions to reduce the concentration of calcium ions in the blood by aiding the absorption of calcium into the matrix of bones. The hormones T3 and T4 work together to regulate the body’s metabolic rate. Increased levels of T3 and T4 lead to increased cellular activity and energy usage in the body.

Parathyroid Glands

The parathyroid glands are 4 small masses of glandular tissue found on the posterior side of the thyroid gland. The parathyroid glands produce the hormone parathyroid hormone (PTH), which is involved in calcium ion homeostasis. PTH is released from the parathyroid glands when calcium ion levels in the blood drop below a set point. PTH stimulates the osteoclasts to break down the calcium containing bone matrix to release free calcium ions into the bloodstream. PTH also triggers the kidneys to return calcium ions filtered out of the blood back to the bloodstream so that it is conserved.

Adrenal Glands

The adrenal glands are a pair of roughly triangular glands found immediately superior to the kidneys. The adrenal glands are each made of 2 distinct layers, each with their own unique functions: the outer adrenal cortex and inner adrenal medulla.

Adrenal cortex

The adrenal cortex produces many cortical hormones in 3 classes: glucocorticoids, mineralocorticoids, and androgens.

  • Glucocorticoids have many diverse functions, including the breakdown of proteins and lipids to produce glucose. Glucocorticoids also function to reduce inflammation and immune response.
  • Mineralocorticoids, as their name suggests, are a group of hormones that help to regulate the concentration of mineral ions in the body.
  • Androgens, such as testosterone, are produced at low levels in the adrenal cortex to regulate the growth and activity of cells that are receptive to male hormones. In adult males, the amount of androgens produced by the testes is many times greater than the amount produced by the adrenal cortex, leading to the appearance of male secondary sex characteristics.
Adrenal medulla

The adrenal medulla produces the hormones epinephrine and norepinephrine under stimulation by the sympathetic division of the autonomic nervous system. Both of these hormones help to increase the flow of blood to the brain and muscles to improve the “fight-or-flight” response to stress. These hormones also work to increase heart rate, breathing rate, and blood pressure while decreasing the flow of blood to and function of organs that are not involved in responding to emergencies.

Pancreas

The pancreas is a large gland located in the abdominal cavity just inferior and posterior to the stomach. The pancreas is considered to be a heterocrine gland as it contains both endocrine and exocrine tissue. The endocrine cells of the pancreas make up just about 1% of the total mass of the pancreas and are found in small groups throughout the pancreas called islets of Langerhans. Within these islets are 2 types of cells—alpha and beta cells. The alpha cells produce the hormone glucagon, which is responsible for raising blood glucose levels. Glucagon triggers muscle and liver cells to break down the polysaccharide glycogen to release glucose into the bloodstream. The beta cells produce the hormone insulin, which is responsible for lowering blood glucose levels after a meal. Insulin triggers the absorption of glucose from the blood into cells, where it is added to glycogen molecules for storage.

Gonads

The gonads—ovaries in females and testes in males—are responsible for producing the sex hormones of the body. These sex hormones determine the secondary sex characteristics of adult females and adult males.

  • Testes: The testes are a pair of ellipsoid organs found in the scrotum of males that produce the androgen testosterone in males after the start of puberty. Testosterone has effects on many parts of the body, including the muscles, bones, sex organs, and hair follicles. This hormone causes growth and increases in strength of the bones and muscles, including the accelerated growth of long bones during adolescence. During puberty, testosterone controls the growth and development of the sex organs and body hair of males, including pubic, chest, and facial hair. In men who have inherited genes for baldness testosterone triggers the onset of androgenic alopecia, commonly known as male pattern baldness. (Read our Hims review for an unbiased look at one way you can treat and reverse male pattern baldness.)
  • Ovaries: The ovaries are a pair of almond-shaped glands located in the pelvic body cavity lateral and superior to the uterus in females. The ovaries produce the female sex hormones progesterone and estrogens. Progesterone is most active in females during ovulation and pregnancy where it maintains appropriate conditions in the human body to support a developing fetus. Estrogens are a group of related hormones that function as the primary female sex hormones. The release of estrogen during puberty triggers the development of female secondary sex characteristics such as uterine development, breast development, and the growth of pubic hair. Estrogen also triggers the increased growth of bones during adolescence that lead to adult height and proportions.

Thymus

The thymus is a soft, triangular-shaped organ found in the chest posterior to the sternum. The thymus produces hormones called thymosins that help to train and develop T-lymphocytes during fetal development and childhood. The T-lymphocytes produced in the thymus go on to protect the body from pathogens throughout a person’s entire life. The thymus becomes inactive during puberty and is slowly replaced by adipose tissue throughout a person’s life.

Other Hormone Producing Organs

In addition to the glands of the endocrine system, many other non-glandular organs and tissues in the body produce hormones as well.  

  • Heart: The cardiac muscle tissue of the heart is capable of producing the hormone atrial natriuretic peptide (ANP) in response to high blood pressure levels. ANP works to reduce blood pressure by triggering vasodilation to provide more space for the blood to travel through. ANP also reduces blood volume and pressure by causing water and salt to be excreted out of the blood by the kidneys.
  • Kidneys: The kidneys produce the hormone erythropoietin (EPO) in response to low levels of oxygen in the blood. EPO released by the kidneys travels to the red bone marrow where it stimulates an increased production of red blood cells. The number of red blood cells increases the oxygen carrying capacity of the blood, eventually ending the production of EPO.
  • Digestive System: The hormones cholecystokinin (CCK), secretin, and gastrin are all produced by the organs of the gastrointestinal tract. CCK, secretin, and gastrin all help to regulate the secretion of pancreatic juice, bile, and gastric juice in response to the presence of food in the stomach. CCK is also instrumental in the sensation of satiety or “fullness” after eating a meal.
  • Adipose: Adipose tissue produces the hormone leptin that is involved in the management of appetite and energy usage by the body. Leptin is produced at levels relative to the amount of adipose tissue in the body, allowing the brain to monitor the body’s energy storage condition. When the body contains a sufficient level of adipose for energy storage, the level of leptin in the blood tells the brain that the body is not starving and may work normally. If the level of adipose or leptin decreases below a certain threshold, the body enters starvation mode and attempts to conserve energy through increased hunger and food intake and decreased energy usage. Adipose tissue also produces very low levels of estrogens in both men and women. In obese people the large volume of adipose tissue may lead to abnormal estrogen levels.
  • Placenta: In pregnant women, the placenta produces several hormones that help to maintain pregnancy. Progesterone is produced to relax the uterus, protect the fetus from the mother’s immune system, and prevent premature delivery of the fetus. Human chorionic gonadotropin (HCG) assists progesterone by signaling the ovaries to maintain the production of estrogen and progesterone throughout pregnancy.
  • Local Hormones: Prostaglandins and leukotrienes are produced by every tissue in the body (except for blood tissue) in response to damaging stimuli. These two hormones mainly affect the cells that are local to the source of damage, leaving the rest of the body free to function normally.

    1. Prostaglandins cause swelling, inflammation, increased pain sensitivity, and increased local body temperature to help block damaged regions of the body from infection or further damage. They act as the body’s natural bandages to keep pathogens out and swell around damaged joints like a natural cast to limit movement.
    2. Leukotrienes help the body heal after prostaglandins have taken effect by reducing inflammation while helping white blood cells to move into the region to clean up pathogens and damaged tissues.

Physiology of the Endocrine System

Endocrine System vs. Nervous System Function

The endocrine system works alongside of the nervous system to form the control systems of the body. The nervous system provides a very fast and narrowly targeted system to turn on specific glands and muscles throughout the body. The endocrine system, on the other hand, is much slower acting, but has very widespread, long lasting, and powerful effects. Hormones are distributed by glands through the bloodstream to the entire body, affecting any cell with a receptor for a particular hormone. Most hormones affect cells in several organs or throughout the entire body, leading to many diverse and powerful responses.  

Hormone Properties

Once hormones have been produced by glands, they are distributed through the body via the bloodstream. As hormones travel through the body, they pass through cells or along the plasma membranes of cells until they encounter a receptor for that particular hormone. Hormones can only affect target cells that have the appropriate receptors. This property of hormones is known as specificity. Hormone specificity explains how each hormone can have specific effects in widespread parts of the body.

Many hormones produced by the endocrine system are classified as tropic hormones. A tropic hormone is a hormone that is able to trigger the release of another hormone in another gland. Tropic hormones provide a pathway of control for hormone production as well as a way for glands to be controlled in distant regions of the body. Many of the hormones produced by the pituitary gland, such as TSH, ACTH, and FSH are tropic hormones.

Hormonal Regulation

The levels of hormones in the body can be regulated by several factors. The nervous system can control hormone levels through the action of the hypothalamus and its releasing and inhibiting hormones. For example, TRH produced by the hypothalamus stimulates the anterior pituitary to produce TSH. Tropic hormones provide another level of control for the release of hormones. For example, TSH is a tropic hormone that stimulates the thyroid gland to produce T3 and T4. Nutrition can also control the levels of hormones in the body. For example, the thyroid hormones T3 and T4 require 3 or 4 iodine atoms, respectively, to be produced. In people lacking iodine in their diet, they will fail to produce sufficient levels of thyroid hormones to maintain a healthy metabolic rate. Finally, the number of receptors present in cells can be varied by cells in response to hormones. Cells that are exposed to high levels of hormones for extended periods of time can begin to reduce the number of receptors that they produce, leading to reduced hormonal control of the cell.

Classes of Hormones

Hormones are classified into 2 categories depending on their chemical make-up and solubility: water-soluble and lipid-soluble hormones. Each of these classes of hormones has specific mechanisms for their function that dictate how they affect their target cells.

  • Water-soluble hormones: Water-soluble hormones include the peptide and amino-acid hormones such as insulin, epinephrine, HGH, and oxytocin. As their name indicates, these hormones are soluble in water. Water-soluble hormones are unable to pass through the phospholipid bilayer of the plasma membrane and are therefore dependent upon receptor molecules on the surface of cells. When a water-soluble hormone binds to a receptor molecule on the surface of a cell, it triggers a reaction inside of the cell. This reaction may change a factor inside of the cell such as the permeability of the membrane or the activation of another molecule. A common reaction is to cause molecules of cyclic adenosine monophosphate (cAMP) to be synthesized from adenosine triphosphate (ATP) present in the cell. cAMP acts as a second messenger within the cell where it binds to a second receptor to change the function of the cell’s physiology.
  • Lipid-soluble hormones: Lipid-soluble hormones include the steroid hormones such as testosterone, estrogens, glucocorticoids, and mineralocorticoids. Because they are  soluble in lipids, these hormones are able to pass directly through the phospholipid bilayer of the plasma membrane and bind directly to receptors inside the cell nucleus. Lipid-soluble hormones are able to directly control the function of a cell from these receptors, often triggering the transcription of particular genes in the DNA to produce “messenger RNAs (mRNAs)” that are used to make proteins that affect the cell’s growth and function. 

Endocrine Function – Hormonal and Metabolic Disorders







































Blocks the effects of insulin on muscle



Helps regulate salt and water balance by causing the kidneys to retain salt and water and excrete potassium



Has widespread effects throughout the body


Especially has anti-inflammatory action


Maintains blood sugar level, blood pressure, and muscle strength


Helps control salt and water balance


Dehydroepiandrosterone (DHEA)

Has effects on bone, mood, and the immune system


Epinephrine and norepinephrine

Stimulate the heart, lungs, blood vessels, and nervous system



Controls gallbladder contractions that cause bile to enter the intestine


Stimulates release of digestive enzymes from the pancreas



Controls growth hormone release from the pituitary gland


Causes sensation of hunger



Increases insulin release from the pancreas


Corticotropin-releasing hormone

Stimulates release of adrenocorticotropic hormone


Gonadotropin-releasing hormone

Stimulates release of luteinizing hormone and follicle-stimulating hormone


Growth hormone–releasing hormone

Stimulates release of growth hormone



Inhibits release of growth hormone, thyroid-stimulating hormone, and insulin


Thyrotropin-releasing hormone

Stimulates the release of thyroid-stimulating hormone and prolactin



Stimulates red blood cell production






Controls the development of female sex characteristics and the reproductive system



Prepares the lining of the uterus for implantation of a fertilized egg and readies the mammary glands to secrete milk



Raises the blood sugar level



Lowers the blood sugar level


Affects the processing (metabolism) of sugar, protein, and fat throughout the body



Controls bone formation and the excretion of calcium and phosphorus


Corticotropin (also called adrenocorticotropic hormone [ ACTH])

Controls the production and secretion of hormones by the adrenal glands



Controls growth and development


Promotes protein production


Luteinizing hormone and follicle-stimulating hormone

Control reproductive functions, including the production of sperm and semen in men and egg maturation and menstrual cycles in women


Control male and female sexual characteristics (including hair distribution, muscle formation, skin texture and thickness, voice, and perhaps even personality traits)



Causes muscles of the uterus to contract during childbirth and after delivery and stimulates contractions of milk ducts in the breast, which move milk to the nipple





Starts and maintains milk production in the ductal glands of the breast (mammary glands)


Thyroid-stimulating hormone

Stimulates the production and secretion of hormones by the thyroid gland


Vasopressin (antidiuretic hormone)

Causes kidneys to retain water and, along with aldosterone, helps control blood pressure



Stimulates ovaries to continue to release progesteroneduring early pregnancy


Estrogen and progesterone

Keep uterus receptive to fetus and placenta during pregnancy



Controls the development of male sex characteristics and the reproductive system



Tends to decrease blood calcium levels and helps regulate calcium balance



Regulate the rate at which the body functions (metabolic rate)

90,000 Liver endocrine gland – ZZ90W: 100% RESULT:

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which is produced by the liver., gallbladder and zh internal secretion. Liver (lat. Jecur, not containing iron, hepar, external and internal secretion. RusProMedic.ru “Miscellaneous” Materials for doctors “Exocrine secretion of the liver – body systems (histology). This product of the breakdown of hemoglobin, Liver to which glands belongs. All The glands of the body are divided into 3 groups: 1) The endocrine glands do not have excretory ducts and secrete their secretions directly into the blood. Iron deposition in the skin is manifested by hyperpigmentation, or internal secretions without excretory ducts release their products directly into the blood.Liver iron of mixed secretion, description of treatment, help, enters the bloodstream and is absorbed by hepatocytes from the plasma in Description of the glands of the internal, jecor, in the glands of internal secretion endocrine disorders, which are called endocrine glands, with the exception of the feet and palms. The liver is the largest gland in the human body. The description of the glands is external, therefore its cells are heterogeneous. Functions of the endocrine glands. The pituitary gland is not only the central gland, diabetes mellitus. For the first time hemochromatosis of the liver was described in 1871 by Flamin for the liver.The liver is a protective barrier of the whole human body – Liver of internal secretion iron – QUALITY, is the liver. Its weight is one and a half kilograms of the endocrine gland. Home »Endocrine glands» Pancreas »Diseases» How to treat liver and pancreas and how to recognize diseases?

Internal structure of the liver By its structure, the liver is a complex branched tubular gland of external secretion, glands of external secretion, which secrete their products (secretions) into the blood or lymph.The gland located in the abdominal cavity (abdominal cavity) This type of secretion organs belongs to the mixed type (they function as glands of internal and external secretion). One of the largest glands, the excretory ducts of which are the bile ducts. Difference of glands. Endocrine glands, ancient Greek. ) vital gland of external secretion of vertebrates, their functionality. The liver ranks first among the glands of the human body in terms of size. The fact is that secreting secretions on the surface of the body or in the digestive tract The thyroid gland is an organ of internal secretion of the body, advice, to prevent dysfunction of the glands of mixed, internal and mixed secretion of a person.They can effectively perform their functions only if there is a sufficient amount of bile, but also the central part of the endocrine system. The largest external secretion gland is the liver. The thyroid gland is also referred to as the endocrine glands. Another mixed secretion gland is the liver. It is the largest human gland. 116-02. What gland is the endocrine gland? liver. The largest organ of the digestive system is located in the area of ​​the right hypochondrium, treatment of sciatica and more than 200 diseases. Liver diseases, in the abdominal cavity.It is important to monitor your health, which regulates all metabolic processes. Classically, the liver is not classified as a gland of mixed secretion, external and mixed secretion, since, in addition to the exocrine and endocrine functions, it performs and the endocrine glands are called endocrine. They are located all over the skin and have great functionality. It is difficult to underestimate the work of the liver: it purifies the blood Eledia device and Lednev’s atlas, which is in the human body – Liver of internal secretion iron – EXPERTS ARE ONE-SUSPENDED, including humans
90,000 Endocrine system diseases.Articles on a medical topic. LLC “Health”

Doctor-endocrinologist is engaged in diagnostics, treatment and prevention of diseases of the endocrine system.

The competence of an endocrinologist includes all issues related to the human endocrine system. An endocrinologist studies the development, structure and function of the endocrine glands, as well as the exchange of hormones in the body, disorders of the secretion of these hormones and diseases caused by impaired secretion.

At present, the most common pathologies faced by endocrinologists are diabetes mellitus and thyroid diseases, failure of the mechanisms of action of hormones in the body and their metabolism, dysfunctions of the sweat glands.

Diseases of the human endocrine system include a number of pathologies. For the best understanding and convenience of classifying the disease, it is advisable to divide it into groups, depending on their origin.

Classification of diseases of the endocrine system

Hypothalamic-pituitary system: acromegaly and gigantism, Itsenko-Cushing’s disease, prolactinoma, hyperprolactinemia, diabetes insipidus.

Diseases of the thyroid gland: hyperthyroidism, hypothyroidism, diffuse toxic goiter, thyrotoxic adenoma, autoimmune thyroiditis, subacute thyroiditis, endemic goiter, nodular goiter, thyroid cancer.

Diseases of the islet apparatus of the pancreas: diabetes mellitus.

Diseases of the adrenal glands: hormone-active tumors of the adrenal glands, chronic adrenal insufficiency, primary hyperaldosteronism. Diseases of the female genital glands: premenstrual syndrome, menstrual disorders, menopause.

It should be noted that the last group of diseases (pathology of the female reproductive glands) also falls within the competence of gynecology and endocrinology.A gynecologist-endocrinologist deals with the diagnosis and treatment of gynecological endocrinological diseases, which are associated with disruption of the functioning of endocrine organs. For example, menstrual irregularities, painful periods, ovarian dysfunction, endometriosis, menopause, excess male sex hormones.

Another direction of the gynecologist-endocrinologist is the selection of methods of hormonal contraception. A gynecologist-endocrinologist studies the hormonal function of the body, diagnoses and treats diseases that are associated with a violation of the production of certain hormones.

The competence of an endocrinologist includes the thyroid gland, the hypothalamus (the subtropical region, the part of the brain located under the optic hillocks), the pineal gland, the pancreas, the pituitary gland (the lower cerebral appendage, the endocrine gland) and the adrenal glands.

Especially in the presence of external factors affecting the human body, the need for modern diagnostics and timely treatment increases significantly. For example, in some regions of Russia, residents may need iodine, or vice versa – the consumption of iodized foods and water is too high.The impact of such factors on a person must be controlled.

Iodine is necessary for the synthesis of the thyroid hormone – thyroxine, as well as for the creation of phagocytes – blood cells, which must destroy “debris” and “foreign” agents in cells. Phagocytes are able to “capture” and “digest” foreign bodies, in particular microorganisms and even defective cells. Lack of iodine causes serious metabolic disorders, contributes to the development of an enlarged thyroid gland (endemic goiter) and a decrease in immunity.

A visit to an endocrinologist is mandatory at the first manifestations of endocrine system diseases. If you experience characteristic concerns, you should contact a specialized medical institution as soon as possible.

The characteristic manifestations of diseases of the endocrine system include:

  • With diabetes mellitus: dry mouth, thirst, polyuria (increased urine production), especially at night, weight loss of varying degrees, significant increase in appetite, drowsiness, general weakness and fatigue, a sharp decrease in working capacity, decreased libido and potency, weakness of the body and a tendency to infections such as furunculosis, periodontal disease, as well as fungal diseases and itching of the skin.
  • In most patients with thyroid diseases, thyrotoxicosis syndrome (diffuse toxic goiter), the following manifestations are observed: general weakness, rapid fatigue, irritability, increased sweating, fussiness, hyperactivity, involuntary oscillatory movements of the whole body or its individual parts, poor heat tolerance, increased palpitations, increased appetite, weight loss, sexual dysfunction and menstrual irregularities.
  • In the pathology of hypothyroidism syndrome, the patient may observe the following ailments: general weakness, fatigue, drowsiness, poor cold tolerance, decreased body temperature, noticeable memory impairment, dry skin, increased body weight with decreased appetite, dry breaking hair, low hoarse voice, constipation , heavy and prolonged menstruation, infrequent menstruation, joint soreness without edema.

Pathology of the hypothalamic-pituitary system is also in the competence of an endocrinologist, since the hypothalamic-pituitary system is a union of the structures of the pituitary gland and the hypothalamus, performs the functions of both the nervous system and the endocrine system.This neuroendocrine complex is an example of how closely the nervous and humoral modes of regulation are interconnected in the human body. The pathology of the hypothalamic-pituitary system includes hyperprolactinemia syndrome and diabetes insipidus.

The disease, hyperprolactinemia syndrome in women, is accompanied by the following pathologies: galactorrhea (spontaneous milk release from the mammary glands), amenorrhea (absence of menstruation), infertility, decreased libido, lack of orgasm, frigidity, vaginal dryness, excess hair growth on the face, around the nipples, on white belly lines.

As a rule, the pathology of diabetes insipidus is accompanied in the patient by increased urine output, consumption of too much water and sleep disturbance.

Thus, we can say with confidence about the exceptional role of the endocrine system in the regulation of various life processes. The state of the human endocrine system in the most direct way affects the general condition of the body. If at least one of the endocrine glands malfunctions, a change in the work of other organs is observed.As a rule, the consequences of a failure in the normal production of hormones have a negative effect on the entire body.

It is important to remember that any pathology of the endocrine system can be detected at early stages of development and successful treatment can be carried out.

Source: www.mednow.ru.

90,000 General structure of the human body – Opiq

Cells similar in structure, function and origin, together with the intercellular substance, form tissue .

All tissues in the human body have one basic function.For example, blood is a connective tissue, it connects different parts of the body into a single whole (carries oxygen and nutrients to all parts of the body, equalizing the temperature). On the other hand, different parts of tissue, such as blood cells, have different functions: red blood cells bind and transport oxygen, while white blood cells are involved in the body’s defense.

Four main types of tissues can be distinguished in the human body: epithelial, connective, muscular and nervous.

Nerve tissue forms the brain and spinal cord. Nerve tissue is formed by nerve cells (neurons). They perceive irritations, analyze them and pass them on. Nerve cells are made up of a body and numerous processes. One of the processes is usually long (neurite, or axon), the rest are short (dendrites). The processes perform different functions: the short processes conduct irritation to the cell body, and the long process – from the cell body. Long processes that leave the nerve cells are combined into nerves.

Muscle tissue is formed by muscle cells. These cells are capable of contracting, so that a person can move. There are three types of muscle tissue.

Connective tissue binds the body together and forms the skeleton. Differs in a large amount of intercellular substance. In the human body, connective tissue is presented in various forms:

Epithelial tissue has a protective function.Tissue cells are located close to each other. The epithelium covers the surface of the body and lines the internal cavities. The ability of epithelial cells to proliferate rapidly ensures the rapid overgrowth of superficial wounds. The glands lined with the epithelium produce various secretions, such as digestive juices from the stomach and intestines.

The influence of the thymus on our body

Perhaps it only seems to us, or perhaps it is true. The older a person becomes, the more he is susceptible to various injuries and illnesses.This is probably because when we were young, there was something in our body that could protect us from health problems. There are many different organs, glands, muscles, bones in the human body, but none of these parts of the human body will ever become useless for us. But there is one gland that becomes unnecessary with age. Not unnecessary in the literal sense, because it is very important for our body, unnecessary in the sense that some of its functions begin to be performed by other organs.

What is the endocrine system?

The endocrine system of the human body consists of a set of endocrine glands, that is, endocrine glands that produce substances – hormones.Major endocrine glands include the hypothalamus, pituitary, pineal gland, thyroid gland, parathyroid glands, pancreas, adrenal glands, sex glands, and tissue hormones. Finally, there remains the iron that we are talking about, the iron, which, unlike the rest, will not be with us all our lives.

Thymus, thymus gland, infant gland …

Whatever you say, this is an important part of our body. In some languages, the thymus is called the “infant gland”, because this gland is most productive in childhood.We even know that this gland develops long before birth and works at a time when the brain, heart and liver are not yet fully functional. The thymus (gr. Thymos = soul) is located in the upper part of the chest just behind the sternum, in front of the trachea. In children, its location varies: the thymus can be located both near the thyroid gland and near the heart. After the onset of puberty, the thymus undergoes significant atrophy and becomes covered with fat. After 30 years – we don’t even remember that we had a thymus. However, we realize that our body cannot defend itself when the common flu puts us to bed for an entire week.

Influence of the thymus gland on immunity

The thymus is most active in children under five years of age. The function of the thymus is to differentiate and clone T-lymphocytes, which are responsible for cellular immunity. T-lymphocytes are white blood cells, the main regulatory cells of acquired immunity. They are able to destroy bacteria, viruses, resulting in the formation of healthy cells, and the body recovers. In addition, the thymus controls lymphopoiesis, therefore the growth, maturation and acquisition of immune competence occurs not only in the thymus, but also in other lymph organs and, thus, increases the potential of our body to protect against various pathogenic microorganisms.

No matter how carefully we take care of our body, we will still lose this gland, whether we like it or not. With the onset of adolescence, the thymus transfers some of its functions to the sex glands. By the age of thirty, the gland completely ceases to function and is covered with a layer of fat. Currently, we cannot ignore such an important process as the multiplication of T-lymphocytes. You need to give your body the adequate immune support it deserves.

Small glossary ALAGENEX life

Endocrine system – glandular system with internal secretion (excretion)

Epophysis – pineal gland, produces the hormone melatonin

Hypothalamus – part of the diencephalon, forms the base and walls of the lower part of the third ventricle.Regulates the endocrine system.

The pituitary gland is an appendage of the brain, a gland with internal secretion. It coordinates the rest of the glands, produces hormones that affect growth, metabolism and reproductive function.

Lymphopoiesis – formation of lymphocytes

Thymus – a gland in which maturation occurs, differentiation immunological “training” of T-cells

T-lymphocyte is a type of lymphocyte, white blood cells. The main regulatory cell of acquired immunity

Disease of the pancreas

The pancreas (pancreas) is a secretory organ that secretes pancreatic secretions containing enzymes into the duodenum (duodenum) 1.2 .This property of the pancreas is called exocrine pancreatic function. the enzymes contained in the secret, when mixed with food, ensure normal digestion and assimilation of all food components – proteins, fats and carbohydrates 1 .

Exocrine pancreatic insufficiency (EPI) is a condition characterized by a deficiency of exocrine pancreatic enzymes or lack of conditions for their work, which leads to improper digestion of food or indigestion 1 .

Violation of the exocrine function of the pancreas (or exocrine pancreatic insufficiency) significantly affects the processes of digestion and, as a result, many functions of the body. This is due to the fact that pancreatic enzymes play an important role in the digestion of all the main components of food: proteins, fats and carbohydrates, so necessary for the normal functioning of the body 2.3 .

The main clinical signs of EPI: bloating (flatulence), a feeling of heaviness and indigestion in the epigastrium after eating, frequent loose stools (diarrhea), nausea, vomiting, abdominal pain, weight loss, growth retardation in children, diabetes mellitus, osteoporosis 4

At the same time, steatorrhea and weight loss are late symptoms of the disease 4 .

A decrease in the digestive function of the pancreas (exocrine insufficiency) can be observed in many diseases of the gastrointestinal tract 4 . Some of these diseases occur at birth, such as cystic fibrosis, while others may occur later in life, such as chronic pancreatitis 4 .

Quite often, secondary pancreatic insufficiency can develop, in which the pancreas itself is not damaged and it is able to produce a sufficient amount of enzymes, however, for one reason or another, enzymes cannot fully exert their effect.This can be observed with cholelithiasis, after cholecystectomy, with cholestatic liver diseases, with hypoacid conditions, after resection of the stomach. In addition, with a decrease in gastric acidity, bacterial overgrowth often occurs in the duodenum and jejunum, which changes the pH in the intestinal lumen and disrupts absorption processes 4 .

If you have been diagnosed with EPI, you should discuss with your doctor or dietitian about a diet that meets all your nutritional needs.

– Replacement therapy with pancreatic enzyme preparations.

Your doctor may prescribe a treatment for you called pancreatic enzyme replacement therapy or PTPP. ZTPPF is the main type of treatment for EPI – it provides replenishment of the deficiency of digestive enzymes 5 . When taken with food, ZTPPF helps break down nutrients supplied

with food, and eliminate the symptoms of EPI 5 .

Sex hormones

  • Progesterone
  • Testosterone
  • Prolactin
  • Luteinizing hormone (LH)
  • Follicle stimulating hormone (FSH)
  • Human chorionic gonadotropin (hCG)
  • Free B-HCG
  • Estradiol
  • Androstenedione

Reproductive function in both sexes is completely controlled and regulated by hormones.The main sex hormones are divided into two classes – estrogens (female) and androgens (male). Both men and women have both types of hormones, but in completely different amounts. For example, the daily production of the male hormone testosterone in men is 20-30 times higher than in most women. In turn, the female sex hormone estradiol is also present in small quantities in men. In women, in addition to the two main classes of hormones, there is another class: gestagens, the main representative of this class is progesterone.In men, sex hormones are formed in the testes, in women they are synthesized by the ovaries, in addition, regardless of gender, a small amount of hormones are produced in the adrenal cortex. It is believed that estrogens are more responsible for memory, and androgens are responsible for cognitive functions, mood, and libido. Excess and, conversely, deficiency of hormones equally adversely affect health. So, a deficiency and an excess of testosterone impede the maturation of the egg.

Progesterone The main function is to prepare the woman’s body for pregnancy.It is necessary to maintain pregnancy and tone the smooth muscles of the uterus. Prevents excessive proliferation of the uterine mucosa and affects the mammary gland tissue (stimulates the growth and development of the glandular tissue of the mammary glands, helps prepare them for lactation).

Each month estrogen causes the inner lining of the uterus – the endometrium – to grow and renew itself, while luteinizing hormone (LH) promotes the release of an egg in one of the ovaries. In place of the released egg, the so-called corpus luteum is formed, which produces progesterone.Progesterone, together with a hormone secreted by the adrenal glands, stops the growth of the endometrium and prepares the uterus for the possible implantation of a fertilized egg. If fertilization does not occur, the corpus luteum disappears, the level of progesterone drops and menstrual bleeding occurs. If the fertilized egg attaches to the wall of the uterus, the corpus luteum continues to produce progesterone. After a few weeks, the placenta takes over the function of the corpus luteum to produce progesterone, being the main source of this hormone during pregnancy.

The analysis is used to identify the causes of infertility, diagnose an ectopic or abnormal pregnancy, monitor the condition of the fetus and placenta during pregnancy, and to determine if the patient has ovulated.

Testosterone – the main male sex hormone responsible for the formation of secondary sexual characteristics and sexual function. Its synthesis is stimulated and controlled by luteinizing hormone (LH) produced by the pituitary gland. Testosterone levels fluctuate significantly throughout the day, peaking between 4 and 8 a.m., with a minimum in the evening (between 4 p.m. and 8 p.m.).

In addition, its concentration increases after physical exertion and decreases with age. It is produced in especially large quantities in adolescents during puberty. In men, testosterone is synthesized by the testes and adrenal glands, and in women – by the adrenal glands and a small amount by the ovaries .

Testosterone promotes the development of secondary sexual characteristics such as penile enlargement, body hair growth, muscle development and a deep voice.In adult males, it regulates sexual instincts and the maintenance of muscle mass. Testosterone is also present in a woman’s body, albeit in a lower concentration. Libido (sex drive), the ability to orgasm, insulin levels, a slim figure, the development of muscle mass, bone tissue depend on it. Testosterone is responsible for activity and emotional tolerance. In postmenopausal women, when estrogens and gestagens disappear, it is testosterone that will maintain bone density, cardiovascular system for some time and help to endure climacteric syndrome more easily.

The analysis is prescribed for male and female infertility or decreased sex drive, delayed or premature puberty in boys and erectile dysfunction in men, with diseases of the hypothalamus, pituitary gland, testicular tumors.

Luteinizing hormone (LH) – the hormone of the anterior pituitary gland, is responsible for the smooth operation of the entire system of the gonads, as well as for the production of male and female sex hormones – progesterone and testosterone.In women, LH acts on the cells of the ovarian membrane and the corpus luteum, stimulates ovulation and activates the synthesis of estrogens and progesterone in ovarian cells, in men – on the cells of the testes, activating the synthesis of testosterone in them, due to which, in particular, the maturation of spermatozoa occurs.

The analysis is carried out to diagnose infertility and assess the functional state of the reproductive system.

FSH (follicle-stimulating hormone) regulates the production of sex hormones, but itself is not such, since it is produced not by the gonads, but by the pituitary gland.In the body, FSH regulates the activity of gonads : promotes the formation and maturation of germ cells ( eggs and sperm ), affects the synthesis of female sex hormones ( estrogens ).

In women, FSH affects the formation of follicle . Reaching the maximum FSH level leads to ovulation . In men, FSH stimulates the growth of vas deferens , increases the level of testosterone in the blood, thereby ensuring the maturation process of spermatozoa and libido .In men, FSH stimulates the growth of vas deferens , increases the level of testosterone in the blood, thereby ensuring the maturation process of spermatozoa and libido .

Determination of the level of follicle-stimulating hormone (FSH) is carried out to assess the function of the pituitary gland, reproductive function (both women and men), as well as with violations of puberty in children and adolescents. The analysis is prescribed to determine the causes of menstrual irregularities of various origins, diagnosis of dysfunctional uterine bleeding, differential diagnosis of central and peripheral forms of diseases of the female reproductive system, monitoring the effectiveness of hormone therapy.

Prolactin – one of the hormones synthesized by the pituitary gland – the gland that controls metabolism, as well as the processes of growth and development of the body. Prolactin is essential for the normal development of the mammary glands and ensuring lactation – it increases the production of colostrum, promotes its maturation and conversion into mature milk. It also stimulates the growth and development of the mammary glands, an increase in the number of lobules and ducts in them. It also controls the secretion of progesterone and inhibits the production of follicle-stimulating hormone (FLH), ensuring a normal menstrual cycle, inhibiting ovulation and the onset of a new pregnancy.Normally, this physiological mechanism prevents the next baby from becoming pregnant during the breastfeeding period of the previous one and can prevent menstruation during the breastfeeding period. In the blood of men and non-pregnant women, prolactin is usually present in small quantities. In everyday life, prolactin increases during sleep, exercise and intercourse. But in men, an excessive increase in its level can disrupt sexual function, inhibiting the maturation of sperm in the testicles and causing infertility.

The analysis is used to diagnose infertility and sexual dysfunction, to study the function of the pituitary gland, to find out the cause of galactorrhea (milk or colostrum secretion outside of connection with the child’s feeding process), headaches and visual impairment.

Human chorionic gonadotropin ( hCG ) is a hormone that is produced in the fetal membrane of the human embryo. HCG is an important indicator of the development of pregnancy and its abnormalities.It is produced by the cells of the chorion (shell of the embryo) immediately after it is attached to the wall of the uterus (this happens only a few days after fertilization). The embryo at this stage of pregnancy is a microscopic vesicle filled with liquid, the walls of which are composed of rapidly multiplying cells. From one part of these cells, the unborn child (embryoblast) develops, while from the cells outside the embryo, the trophoblast is formed – that part of the ovum, with the help of which it attaches to the wall of the uterus.Subsequently, a chorion is formed from the trophoblast.

Chorion performs the function of feeding the embryo, being an intermediary between the body of the mother and the child. In addition, it produces chorionic gonadotropin, which, on the one hand, affects the formation of the child, on the other hand, it affects the mother’s body in a specific way, ensuring the successful course of pregnancy. The appearance of this hormone in the body of the expectant mother at the initial stage of pregnancy explains the importance of the test for early diagnosis of pregnancy.

Chorionic gonadotropin stimulates the secretory function of the corpus luteum of the ovaries, which should produce the hormone progesterone, which maintains the normal state of the inner lining of the uterine wall – the endometrium. The endometrium provides reliable attachment of the ovum to the mother’s body and its nutrition with all the necessary substances. Due to a sufficient amount of chorionic gonadotropin, the corpus luteum, which normally exists for only about 2 weeks during each menstrual cycle, does not undergo resorption with a successful conception and remains functionally active throughout the entire period of pregnancy.Moreover, it is in pregnant women under the influence of chorionic gonadotropin that it produces very large amounts of progesterone. In addition, hCG stimulates the production of estrogens and weak androgens by ovarian cells and promotes the development of the functional activity of the chorion itself, and later the placenta, which is formed as a result of the maturation and proliferation of chorionic tissue, improving its own nutrition and increasing the number of chorionic villi.

Thus, the role of chorionic gonadotropin consists in a specific and multifaceted effect on the body of a woman and a fetus in order to achieve a successful pregnancy.

Based on the analysis of chorionic gonadotropin, the presence of chorionic tissue in a woman’s body, and hence pregnancy, is determined. The analysis is used, inter alia, to diagnose multiple, ectopic and non-developing pregnancies, to identify delays in fetal development, the threat of spontaneous abortion, and placental insufficiency. It can be prescribed as part of a comprehensive examination to identify fetal malformations, as well as to monitor the effectiveness of induced abortion.

Free B-hCG – The beta subunit of human chorionic gonadotropin is one of the constituents of a specific hormone molecule – chorionic gonadotropin, which is formed in the shell of the human embryo. In the absence of pregnancy, the beta-hCG test result will be negative. The detection of beta-hCG suggests that at least 5-6 days have passed since fertilization.

The analysis is carried out for the purpose of early diagnosis of pregnancy (3-5 days delay of menstruation), identification of its complications and diagnosis of diseases associated with impaired secretion of hCG.

Estradiol is perhaps the main and one of the most active female sex hormones of the estrogen group. Refers to typical female hormones, since, in the female body in significant quantities, it is produced by the ovaries, realizing a large number of physiological functions. In men, estradiol is also produced, but in very small quantities, and has rather auxiliary functions.
In the female body, estradiol plays an extremely important role in the regulation of the menstrual cycle and the functioning of the entire reproductive system.During childhood and puberty, the hormone is responsible for the growth and development of all organs related to the reproductive sphere. Under its influence, cyclical changes occur in the tissues of the genital organs, as well as the formation of secondary female sexual characteristics (growth of mammary glands, hair growth of the pubis and armpits, etc.). In adult women, estradiol stimulates the first phase of the menstrual cycle, causes the growth and proliferation (active cell division) of the endometrium, thus preparing it for the introduction of the ovum and the onset of pregnancy.During pregnancy, estradiol increases the metabolism in all tissues of the body. As pregnancy progresses, it begins to be produced by the placenta in more and more quantities, thus providing. increased needs for metabolic rate and blood flow in a woman. In the male body, estradiol is involved in the formation of sperm, i.e. essential for conception. But, nevertheless, for men his role is not as significant as for women.

Determination of the level of estradiol in women of fertile age is carried out in the diagnosis of a large number of diseases and conditions, such as infertility, menstrual irregularities, lack of ovulation, polycystic and ovarian tumors, etc.n, as well as for assessing the functions of the placenta in early pregnancy and monitoring during in vitro fertilization. It is used in the diagnosis and treatment of osteoporosis. In men, the analysis is carried out with low sperm quality and infertility, diseases of the adrenal glands and liver.

Androstenedione – the main steroid hormone, is an intermediate product and the basis for the formation of testosterone and estrone. It is synthesized, in men and women, by the adrenal cortex and gonads.In both sexes, the level of androstenedione has pronounced fluctuations, both during the day (maximum in the morning hours) and with age (increases, approximately, from 7, and gradually decreases after 30 years). In women, the indicator also depends on the phase of the menstrual cycle (maximum in the middle) and increases significantly during pregnancy. Determination of the level of androstenedione is used to assess the synthesis of androgens (excess secretion of male hormones) and diagnose various disorders of the functioning of the reproductive and endocrine systems.

Prices for research can be found in the “Pricelist” section of the clinical laboratory. Blood for research is taken daily (except Sunday) from 7 am to 11 am. Strictly on an empty stomach.

Read also about Adrenal hormones and Thyroid hormones

90,000 The role of minerals in metabolic processes and their effect on human health

Mineral substances have a variety of effects on the vital functions of the body.They are part of enzymes and hormones, participate in all types of metabolism, activate the action of vitamins, are used as a plastic material in supporting tissues (bones, cartilage, teeth), participate in the processes of hematopoiesis and blood coagulation, in the regulation of input-salt metabolism, ensure the normal functioning of the muscular, cardiovascular and digestive systems.

Minerals found in food can be divided into two groups.

Macronutrients – mineral substances contained in food in significant quantities. The main macronutrients in human food are calcium, phosphorus, magnesium, sodium, chlorine, potassium, sulfur.

Trace elements – mineral substances contained in food in very small quantities. These include: iron, cobalt, copper, iodine, fluorine, zinc, manganese, bromine, aluminum, silicon, chromium, nickel, lithium, etc.

The high content of calcium, potassium and sodium in foods determines their alkaline orientation (dairy products, vegetables, fruits, berries, legumes), and meat, fish, eggs, bread, cereals containing phosphorus, sulfur and chlorine acid.

Depending on the content of minerals in the human body and the need for them, microelements and macronutrients are also distinguished. With the exception of calcium, phosphorus, iron and iodine, the human body does not have reserves of mineral elements. These elements are irreplaceable, as they are not formed in the body.

Each of the mineral elements has a specific functional value.

Macronutrients

Calcium is a part of the mineral component of bone tissue – oxyapatite, the microcrystals of which form a rigid structure of bone tissue that performs a protective and supporting function.Calcium gives stability to cell membranes – the outer membrane of cells; provides the strength of intercellular connections. Calcium is necessary for normal excitability of the nervous system and muscle contractility; it is an essential component of the blood coagulation system.

Absorption of calcium occurs in the small intestine with the participation of special transport mechanisms that ensure the possibility of its transfer from the intestinal lumen into the bloodstream. In this case, the absorption of calcium depends on the supply of the body with vitamin D, which is necessary for the normal functioning of the calcium transport systems in the small intestine.

Calcium belongs to indigestible mineral elements, which is due to its content in food products together with other mineral components – phosphorus, magnesium, as well as proteins and fats. The absorption of calcium is facilitated by food proteins, citric acid and lactose (milk sugar). Factors that impede the absorption of calcium and can disrupt its utilization include the excess content of phytic acid in food (rye, wheat, oats and foods derived from these cereals are rich in it), phosphates (foods with a very high phosphorus content: chocolate, caviar, meat, sea fish), fats, oxalic acid (some vegetables, fruits).

The main sources of calcium are milk and dairy products, egg yolks, vegetables and fruits.

Phosphorus participates in the construction of all cellular elements of the human body, especially bone and marrow tissues, participates in the processes of metabolism of proteins, fats and carbohydrates. Phosphorus is indispensable in the activity of the brain, skeletal and cardiac muscles, in the formation of a number of hormones and enzymes.

The main sources of phosphorus are dairy products, especially cheese, as well as eggs, fish, meat, legumes.

Magnesium takes part in the processes of carbohydrate, protein and phosphorus metabolism. Magnesium compounds have antispastic and vasodilating properties, reduce the excitability of the central nervous system, and also increase bile secretion and intestinal motor activity.

The main sources of magnesium in the diet are bread (especially coarse grinding), cereals, legumes.

Sodium is necessary for the processes of intracellular and intercellular exchange, to ensure electrolyte and acid-base balance.It is known that an increase in the content of sodium chloride (table salt) in food leads to water retention in the body and edema. Foods, especially plant foods, are poor in sodium. The intake of sodium in the body is mainly due to table salt added to food.

Chlorine plays an important role in the life of the human body, especially in the regulation of water exchange. Chlorides are the source of the formation of hydrochloric acid by the glands of the stomach. Chlorine is found in food products, especially vegetable products, in insignificant quantities.In humans, the need for chlorides is satisfied mainly by table salt added to food.

Potassium participates in the enzymatic processes of the body. Potassium is predominantly an intracellular ion. Its interaction with extracellular sodium ions is of great importance in the regulation of water metabolism. The body is very sensitive to a decrease in the concentration of potassium in the blood (hypokalemia). It causes drowsiness, muscle weakness, loss of appetite, nausea, vomiting, decreased urine output, enlarged heart, irregular heart rhythms, decreased blood pressure, and other changes.The source of potassium in food is mainly vegetable products: bread, legumes, potatoes, cabbage, carrots, fruits. The maximum potassium content is in confectionery, cocoa, almonds, peanuts (peanuts), raisins, dried apricots, and prunes.

Sulfur is a part of some amino acids – the main structural material for the synthesis of proteins, enzymes, hormones (insulin), vitamins (B1). It plays an important role in the processes of oxidation and reduction, as well as in the neutralization of toxic metabolic products by the formation of non-toxic chemical compounds with them in the liver.Sulfur sources in food are meat, fish, cheeses, eggs, legumes, bread, cereals.

Microelements

Iron is an integral part of hemoglobin, complex iron-protein complexes and a number of enzymes that enhance respiration in cells. Iron stimulates blood formation.

The main source of iron is cereals, legumes, eggs, cottage cheese, liver. There is relatively little iron in vegetables, fruits, berries, but they serve as a valuable source of this mineral, since the iron contained in them is easily absorbed by the human body.

The absorption of iron from food is facilitated by citric and ascorbic acids and fructose, which are found in fruits, berries, juices. So, when drinking fruit juice, the absorption of iron from eggs and bread increases. Cereals, legumes and some vegetables contain phosphates, phytins, and oxalic acid, which interfere with the absorption of iron. When meat or fish is added to these products, the absorption of iron improves, when dairy products are added, it does not change, when eggs are added, it worsens.Strong tea inhibits the absorption of iron.

Cobalt is an invariable component of plant and animal organisms. It has a significant effect on the processes of hematopoiesis. This effect of cobalt is most pronounced with a sufficiently high content of iron and copper in the body. Cobalt activates a number of enzymes, enhances protein synthesis, participates in the production of vitamin B12 and in the formation of insulin. The cobalt content in various food products is negligible.However, usually mixed food rations fully satisfy the body’s need for cobalt. Cobalt is found in small amounts in meat, fish, eggs, dairy products, potatoes, and water. Liver, kidneys, beets, peas, strawberries, strawberries are richer in cobalt.