The Endocrine System and Glands of the Human Body: Function and Disorders

Written by Barbara Brody

• What Is the Endocrine System?
• What Is a Gland?
• Endocrine System Functions
• Parts of the Endocrine System
• Health Issues
• Endocrine System Disorders
• More

The endocrine system is a network of glands in your body that make the hormones that help cells talk to each other. They’re responsible for almost every cell, organ, and function in your body.

If your endocrine system isn’t healthy, you might have problems developing during puberty, getting pregnant, or managing stress. You also might gain weight easily, have weak bones, or lack energy because too much sugar stays in your blood instead of moving into your cells where it’s needed for energy.

A gland is an organ that makes and puts out hormones that do a specific job in your body. Endocrine and exocrine glands release the substances they make into your bloodstream.

Your endocrine system:

• Makes hormones that control your moods, growth and development, metabolism, organs, and reproduction
• Controls how your hormones are released
• Sends those hormones into your bloodstream so they can travel to other body parts

Many glands make up the endocrine system. The hypothalamus, pituitary gland, and pineal gland are in your brain. The thyroid and parathyroid glands are in your neck. The thymus is between your lungs, the adrenals are on top of your kidneys, and the pancreas is behind your stomach. Your ovaries (if you’re a woman) or testes (if you’re a man) are in your pelvic region.

• Hypothalamus. This organ connects your endocrine system with your nervous system. Its main job is to tell your pituitary gland to start or stop making hormones.
• Pituitary gland. This is your endocrine system’s master gland. It uses information it gets from your brain to tell other glands in your body what to do. It makes many important hormones, including growth hormone; prolactin, which helps breastfeeding moms make milk; antidiuretic hormone(ADH) (vasopressin), which controls blood pressure and helps control body water balance through its effect on the kidney, corticotropin /ACTH: Adrenocorticotrophic hormone. which stimulates the adrenal gland to make certain hormones, thyroid-stimulating hormone (TSH), which stimulates the production and secretion of thyroid hormones, oxytocin which helps in milk ejection during breast feeding; and luteinizing hormone, which manages estrogen in women and testosterone in men.
• Pineal gland. It makes a chemical called melatonin that helps your body get ready to go to sleep.
• Thyroid gland. This gland makes thyroid hormone, which controls your growth and metabolism. If this gland doesn’t make enough (a condition called hypothyroidism), everything happens more slowly. Your heart rate might slow down. You could get constipated. And you might gain weight. If it makes too much (hyperthyroidism), everything speeds up. Your heart might race. You could have diarrhea. And you might lose weight without trying. The thyroid gland also produces the hormone calcitonin, which may contribute to bone strength by helping calcium to be incorporated into bone.
• Parathyroid. This is a set of four small glands behind your thyroid. They play a role in bone health. The glands control your levels of calcium and phosphorus.
• Thymus. This gland makes white blood cells called T-lymphocytes that fight infection and are crucial as a child’s immune system develops. The thymus starts to shrink after puberty.
• Adrenals. Best known for making the “fight or flight” hormone adrenaline (also called epinephrine), these two glands also make hormones called corticosteroids. They affect your metabolism heart rate, oxygen intake, blood flow, and sexual function, among other things.
• Pancreas. This organ is part of both your digestive and endocrine systems. It makes digestive enzymes that break down food. It also makes the hormones insulin and glucagon. These ensure you have the right amount of sugar in your bloodstream and your cells.
• If you don’t make insulin, which is the case for people with type 1 diabetes, your blood sugar levels can get dangerously high. In type 2 diabetes, the pancreas usually makes some insulin but not enough.
• Ovaries. In women, these organs make estrogen and progesterone. These hormones help develop breasts at puberty, regulate the menstrual cycle, and support a pregnancy.
• Testes. In men, the testes make testosterone. It helps them grow facial and body hair at puberty. It also tells the penis to grow larger and plays a role in making sperm.

As you get older, it’s natural to notice some things related to your endocrine system. Your metabolism tends to slow down. So you might gain weight even though you haven’t changed how you eat or exercise. Hormonal shifts also explain, at least in part, why you’re more likely to have heart disease, osteoporosis, and type 2 diabetes as you age.

No matter how old you are, stress, infections, and being around certain chemicals can also mess with parts of your endocrine system. And genetics or lifestyle habits can increase your chances of an endocrine disorder like hypothyroidism, diabetes, or osteoporosis.

• Acromegaly. Sometimes the pituitary gland makes too much growth hormone and your bones get bigger. It usually affects your hands, feet, and face. It usually starts in middle age.
• Adrenal insufficiency. When you have this, your adrenal glands don’t make enough of certain hormones, like cortisol, which controls stress.
• Cushing’s disease. In this, your body makes too much cortisol. You could gain weight, get stretch marks, bruise easily at first, then get weakened muscles and bones and possibly develop a hump on your upper back.
• Hyperthyroidism. This is when your thyroid gland makes more hormones than your body needs. You might hear it called overactive thyroid. It makes your system run fast and you might feel nervous, lose weight, and have a rapid heartbeat or trouble sleeping.
• Hypothyroidism. When your body doesn’t make enough thyroid hormone, your system slows down. You might feel tired, gain weight, have a slow heartbeat, and get joint and muscle pains.
• Hypopituitarism. Sometimes your pituitary gland doesn’t make enough of certain hormones and your adrenal and thyroid glands can’t work right.
• Multiple endocrine neoplasia. This is a group of disorders that affect your endocrine system. It causes tumors on at least two endocrine glands or in other organs and tissues.
• Polycystic ovary syndrome. An imbalance of reproductive hormones can cause your ovaries to either not make an egg or not release it during ovulation. This can throw off your periods, cause acne, and make hair to grow on your face or chin.
• Precocious puberty. When glands that control reproduction don’t work properly, some kids start puberty abnormally early — around 8 in girls and 9 in boys.

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Endocrine System (for Teens) – Nemours KidsHealth

What Is the Endocrine System?

The endocrine system is made up of glands that make hormones. Hormones are the body’s chemical messengers. They carry information and instructions from one set of cells to another.

The endocrine (pronounced: EN-duh-krin) system influences almost every cell, organ, and function of our bodies.

What Does the Endocrine System Do?

• Endocrine glands release
  hormonesinto the bloodstream. This lets the hormones travel to cells in other parts of the body.
• The endocrine hormones help control mood, growth and development, the way our organs work,
  metabolism, and reproduction.
• The endocrine system regulates how much of each hormone is released. This can depend on levels of hormones already in the blood, or on levels of other substances in the blood, like calcium. Many things affect hormone levels, such as stress, infection, and changes in the balance of fluid and minerals in blood.

Too much or too little of any hormone can harm the body. Medicines can treat many of these problems.

What Are the Parts of the Endocrine System?

While many parts of the body make hormones, the major glands that make up the endocrine system are the:

• hypothalamus
• pituitary
• thyroid
• parathyroids
• adrenals
• pineal body
• the ovaries
• the testes

The pancreas is part of the endocrine system and the digestive system. That’s because it secretes hormones into the bloodstream, and makes and secretes enzymes into the digestive tract.

Hypothalamus: The hypothalamus (pronounced: hi-po-THAL-uh-mus) is in the lower central part of the brain. It links the endocrine system and nervous system. Nerve cells in the hypothalamus make chemicals that control the release of hormones secreted from the pituitary gland. The hypothalamus gathers information sensed by the brain (such as the surrounding temperature, light exposure, and feelings) and sends it to the pituitary. This information influences the hormones that the pituitary makes and releases.

Pituitary: The pituitary (pronounced: puh-TOO-uh-ter-ee) gland is at the base of the brain, and is no bigger than a pea. Despite its small size, the pituitary is often called the “master gland.” The hormones it makes control many other endocrine glands.

The pituitary gland makes many hormones, such as:

• growth hormone, which stimulates the growth of bone and other body tissues and plays a role in the body’s handling of nutrients and minerals
• prolactin (pronounced: pro-LAK-tin), which activates milk production in women who are breastfeeding
• thyrotropin (pronounced: thy-ruh-TRO-pin), which stimulates the thyroid gland to make thyroid hormones
• corticotropin (pronounced: kor-tih-ko-TRO-pin), which stimulates the adrenal gland to make certain hormones
• antidiuretic (pronounced: an-ty-dy-uh-REH-tik) hormone, which helps control body water balance through its effect on the kidneys
• oxytocin (pronounced: ahk-see-TOE-sin), which triggers the contractions of the uterus that happen during labor

The pituitary also secretes endorphins (pronounced: en-DOR-fins), chemicals that act on the nervous system and reduce feelings of pain. The pituitary also secretes hormones that signal the reproductive organs to make sex hormones. The pituitary gland also controls
ovulationand the menstrual cycle in women.

Thyroid: The thyroid (pronounced: THY-royd) is in the front part of the lower neck. It’s shaped like a bow tie or butterfly. It makes the thyroid hormones thyroxine (pronounced: thy-RAHK-sin) and triiodothyronine (pronounced: try-eye-oh-doe-THY-ruh-neen). These hormones control the rate at which cells burn fuels from food to make energy. The more thyroid hormone there is in the bloodstream, the faster chemical reactions happen in the body.

Thyroid hormones are important because they help kids’ and teens’ bones grow and develop, and they also play a role in the development of the brain and nervous system.

Parathyroids: Attached to the thyroid are four tiny glands that work together called the parathyroids (pronounced: par-uh-THY-roydz). They release parathyroid hormone, which controls the level of calcium in the blood with the help of calcitonin (pronounced: kal-suh-TOE-nin), which the thyroid makes.

Adrenal Glands: These two triangular adrenal (pronounced: uh-DREE-nul) glands sit on top of each kidney. The adrenal glands have two parts, each of which makes a set of hormones and has a different function:

1. The outer part is the adrenal cortex. It makes hormones called corticosteroids (pronounced: kor-tih-ko-STER-oydz) that help control salt and water balance in the body, the body’s response to stress, metabolism, the immune system, and sexual development and function.
2. The inner part is the adrenal medulla (pronounced: muh-DUH-luh). It makes catecholamines (pronounced: kah-tuh-KO-luh-meenz), such as epinephrine (pronounced: eh-puh-NEH-frun). Also called adrenaline, epinephrine increases blood pressure and heart rate when the body is under stress.

Pineal: The pineal (pronounced: pih-NEE-ul) body, also called the pineal gland, is in the middle of the brain. It secretes melatonin (pronounced: meh-luh-TOE-nin), a hormone that may help regulate when you sleep at night and when you wake in the morning.

Reproductive Glands: The gonads are the main source of sex hormones. Most people don’t realize it, but both guys and girls have gonads. In guys the male gonads, or testes (pronounced: TES-teez), are in the scrotum. They secrete hormones called androgens (pronounced: AN-druh-junz), the most important of which is
testosterone(pronounced: tess-TOSS-tuh-rone). These hormones tell a guy’s body when it’s time to make the changes associated with puberty, like penis and height growth, deepening voice, and growth in facial and pubic hair. Working with hormones from the pituitary gland, testosterone also tells a guy’s body when it’s time to make sperm in the testes.

A girl’s gonads, the ovaries (pronounced: OH-vuh-reez), are in her pelvis. They make eggs and secrete the female hormones
estrogen(pronounced: ESS-truh-jen) and
progesterone(pronounced: pro-JESS-tuh-rone). Estrogen is involved when a girl starts puberty. During puberty, a girl will have breast growth, start to accumulate body fat around the hips and thighs, and have a growth spurt. Estrogen and progesterone are also involved in the regulation of a girl’s menstrual cycle. These hormones also play a role in pregnancy.

Pancreas: The pancreas (pronounced: PAN-kree-us) makes insulin (pronounced: IN-suh-lin) and glucagon (pronounced: GLOO-kuh-gawn), which are hormones that control the level of glucose, or sugar, in the blood. Insulin helps keep the body supplied with stores of energy. The body uses this stored energy for exercise and activity, and it also helps organs work as they should.

How Can I Help Keep My Endocrine System Healthy?

To help keep your endocrine system healthy:

• Get plenty of exercise.
• Eat a nutritious diet.
• Go for regular medical checkups.
• Talk to the doctor before taking any supplements or herbal treatments.
• Let the doctor know about any family history of endocrine problems, such as diabetes or thyroid problems.

When Should I Call the Doctor?

Let the doctor know if you:

• drink a lot of water but are still thirsty
• have to pee often
• have frequent belly pain or nausea
• are very tired or weak
• are gaining or losing a lot of weight
• have tremors or sweat a lot
• are constipated
• are not growing or developing as expected

Medically reviewed by: Larissa Hirsch, MD

Date reviewed: October 2018

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Home / Endocrinology – Endocrine system

Endocrine system regulates the functions of internal organs. This regulation is carried out by hormones secreted by endocrine cells directly into the blood or carried to neighboring cells through the cell membrane. Endocrinology studies all these processes.

The endocrine system is divided into glandular and diffuse. Glandular – this is when the endocrine glands are “scattered” throughout the body. Diffuse – these are already endocrine cells, which are also “scattered” throughout the body. Endocrine cells “share” with the body hormones – aglandular peptides.

Of course, the functions of the endocrine system are vital for a person. It is involved in the chemical regulation of organs, systems and the body as a whole.

It is involved (along with the immune and nervous system) in the growth and development of the body, in sexual differentiation, controls reproductive function and energy conservation.

Hormones produced by the endocrine system , along with the nervous system play an important role in the psycho-emotional state of a person.

What are these hormones? Hormones are carriers that enter the bloodstream to deliver chemicals to cells throughout the body. As already mentioned, hormones are produced in the endocrine glands and are proteins, steroids or protein derivatives.

As it became known, hormones are also produced by organs – the heart, liver, brain.

To date, we are familiar with more than 60 hormones, most of which cannot be stored in the body in reserve, with the exception of thyroglobulin produced by the thyroid gland, which can be stored for 2 days, as well as vitamin D, which is stored in reserve in the liver.

In order for the body to function properly, hormones must be constantly produced. How many hormones the endocrine glands will produce directly depends on the state of the physical, mental, age, and time of day.

Some types of hormones enter the blood in impulses – portions. Hormones, synthesized in one place and entering the bloodstream, are transported to cells throughout the body. Some hormones are characterized by “moving” to “their” target cells by attaching to transport proteins, carrier proteins.

Hormones are excreted from the body in their original form with urine and bile. The main amount of hormones is processed in the liver and leaves the body with bile.

The hypothalamus is the center for regulating the production of hormones by the endocrine glands and their release into the blood. It is located in the brain, it is in it that hormones called liberins are formed – stimulants of another central endocrine organ – the pituitary gland. Liberins “come” to the pituitary gland from the hypothalamus and stimulate the pituitary gland to produce its own hormones – tropins. Tropins, in turn, stimulate the production of hormones by the endocrine glands, which are the main link in the entire chain.

At the same time, the hormones produced by the endocrine glands contribute to the normal functioning of the hypothalamic-pituitary system. When the concentration of hormones in the blood increases, liberins are “released in reduced quantities” by the hypothalamus, which leads to a reduction in the production of tropins by the pituitary gland, and this is the result of a decrease in hormone production. Thus, the hormone itself regulates its own production.

The scheme described above does not include a description of the entire complex system of regulation of hormonal work in the body, since there are a wide range of significant factors. When work is needed and the amount of hormones is regulated very quickly.

Hormone dysfunction may occur in the following cases:

• Hormone deficiency. With a reduction in the production of hormones by the endocrine gland, a heart attack can occur as a result, infections, autoimmune processes, hereditary diseases are activated, and tumors may appear.
• Excessive production of the hormone with its subsequent release into the blood is observed in case of excessive synthesis of them by the endocrine glands, and also when the hormone begins to be produced by tissues (may be during malignant degeneration), an increased release of hormones from the precursor by tissues can also be observed. An iatrogenic cause of an increase in the hormone in the blood is considered to be the case when the hormone is administered in excess in the form of a medicine.
• Synthesis of abnormal hormones by the endocrine glands, which is explained by the presence of genetic abnormalities.
• Resistance (immunity) to hormones, which manifests itself in an inadequate response of body tissues to normal or elevated levels of hormones. Causes: heredity, defects in tissue receptors, production of antibodies to hormones by the body.

Endocrine glands:

1. The pituitary gland is a special gland, as it not only produces hormones, but also influences their production by other glands in the same organism. The pituitary gland is located at the base of the brain and is connected to the hypothalamus by a group of nerve fibers. Together (the pituitary and hypothalamus) control metabolic processes throughout the body, thereby providing all organs with the necessary substances for full-fledged activity.

2. The thyroid gland is located at the level of the larynx.

3. Parathyroid glands, which are located next to the thyroid gland.

4. The pancreas is the largest of all. She is two glands in one. Insulin is a hormone produced by the pancreas, diseases due to malfunction of the pancreas can be serious, one of which is diabetes mellitus. Diseases characteristic of the pancreas are acute pancreatitis, chronic pancreatitis, tumor, lipomatosis. If there are problems with the pancreas, treatment should be started on time, in order to avoid the development of irreversible processes or the transition of the disease to a chronic form. In any case, for problems with the pancreas, treatment is supplemented by a strict diet.

Violations in any area of ​​the endocrine system can lead to many violations of processes in the body. Endocrinology is a branch of medicine that deals with the study of the endocrine system. You can monitor the state of ES, carry out prevention, diagnose diseases and treat them under the supervision of an endocrinologist. A good endocrinologist will help diagnose the disorder itself and the cause of disorders in the functioning of the ES and select the right treatment.

Endocrinology in Irkutsk and consultation with a good endocrinologist are available at the clinic “For the whole family”. Qualified specialists of our clinic will be able to conduct a detailed consultation, examination and treatment.

Price list for endocrinologist services

reception and get detailed advice from a specialist:

1) by phone: +7 (3952) 390 – 292; 404 – 200 (Zheleznodorozhnaya 2nd, 74)

2) by phone: +7 (3952) 205-749; 723 – 749 (Karl-Liebknecht, 152)

Which nervous system regulates the endocrine system

The human body is a complex mechanism. Its cells, tissues and organs must work harmoniously and harmoniously. This condition is ensured by the work of two signaling systems: endocrine and nervous. Their interconnection provides several important conditions:

• homeostasis – the body’s ability to maintain constant characteristics;
• adaptation – the ability to change some factors of the internal environment depending on changes in external conditions;
• cell growth;
• reproduction.

The nervous system is a collection of organs that provide innervation to all organs and tissues. Its central section includes the brain and spinal cord, and the peripheral section includes the nerves. Information is captured by receptors, then moves in the form of impulses through nerve cells and reaches the brain. It provides a quick reaction in the form of muscle movement or other response to a stimulus. Also, the nervous system regulates the work of the endocrine system, controlling the intensity of hormone production.

The endocrine system is a collection of glands that secrete hormones into the blood. It includes the hypothalamus, pituitary gland, as well as peripheral glands: thyroid, pancreas, genital, adrenal glands. Hormones are biologically active substances that combine with the cells of various organs and can change their work, speed up or slow down biochemical processes in the body.

To understand which nervous system regulates the work of the endocrine system, you need to track the relationship. It is called “neuroendocrine regulation” and consists in controlling the production of hormones by the endocrine glands. This process is ensured by the work of several structures: the hypothalamus, neurotransmitter hormones, and the adrenal medulla.

The role of the hypothalamus

The hypothalamus is a small area of ​​the diencephalon, which is considered the center of neuroendocrine regulation. It is connected with other parts of the nervous system, the brain and spinal cord. Together with the pituitary gland, it forms the hypothalamic-pituitary system and regulates the intensity of the production of its hormones.

The hypothalamus receives signals from the following structures:

• basal nuclei (ganglia) – accumulations of gray matter in the white matter of the brain;
• spinal cord;
• parts of the brain: oblong, middle, thalamus, as well as some parts of the cerebral hemispheres.

The hypothalamus is the center that accumulates data from the whole organism, as well as from the external environment. Nerve cells of the hypothalamus are able to produce several types of neuroendocrine transmitters – biologically active substances that affect the intensity of the synthesis of tropic pituitary hormones:

1. Liberins – a group of compounds that stimulate hormonal synthesis. So, somatoliberin increases the production of somatotropic growth hormone, thyreoliberin – thyrotropic, gonadoliberin – luteinizing and follicle-stimulating hormones.
2. Statins are substances that suppress the production of tropic hormones by the pituitary gland. There are varieties such as somatostatin, prolactostatin, melanostatin.
3. Oxytocin and vasopressin are hormones produced by the hypothalamus but stored in the posterior pituitary gland. The first increases during childbirth and causes contraction of the muscular wall of the uterus, but also performs other functions. Vasopressin regulates water metabolism, increases vascular tone.

Hormones of the hypothalamus enter the pituitary gland through the bloodstream and there affect its functions. Statins and liberins do not always act strictly selectively. So, somatostatin can suppress the production of not only somatotropin, but also thyrotropic hormone, insulin and prolactin.

Nervous regulation of the adrenal glands

Adrenal glands are paired glands, which in humans are located in the region of the upper pole of the kidneys. In their structure, two components are distinguished: cortical and medulla. The cortex performs an endocrine function and produces hormones into the blood, and the medulla is an intermediate link between the nervous and endocrine systems.

One of the functions of the adrenal medulla is the production of catecholamines. This is a group of biologically active compounds that includes epinephrine and norepinephrine. They are activated to the maximum in stressful situations, when it is urgent to bring the body into tone, and trigger a number of changes:

• increased heart rate;
• increased vascular tone;
• increase in blood pressure;
• expansion of the bronchial lumen;
• inhibition of the digestive tract and a decrease in the secretion of its glands;
• dilated pupils;
• increased activity of sweat glands.

The adrenal medulla has a similar structure to the nervous tissues, since during fetal development it is formed from identical rudiments. Histologically, the cells in this area are deformed neurons of the sympathetic autonomic nervous system, which then transformed into endocrine cells. They are activated under the influence of sympathetic nerve fibers. As a result of their irritation, adrenaline and norepinephrine are released into the bloodstream.

Catecholamines are considered “stress hormones” because their concentration increases in uncomfortable conditions for the body. They are activated during times of pain, exposure to cold, exercise, and muscle fatigue. Also, their increase can be caused by stress, vivid emotions, prolonged mental stress and other factors. The work of the adrenal medulla is controlled by structures such as the cerebral cortex and medulla oblongata, as well as the hypothalamus.

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In the process of neuroendocrine regulation, a two-way connection is observed.