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What are the chemicals produced by the endocrine system: Glands and Hormones – Genes and Disease

Endocrine System (for Parents) – 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 (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 (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 (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 (pro-LAK-tin), which activates milk production in women who are breastfeeding
  • thyrotropin (thy-ruh-TRO-pin), which stimulates the thyroid gland to make thyroid hormones
  • corticotropin (kor-tih-ko-TRO-pin), which stimulates the adrenal gland to make certain hormones
  • antidiuretic (an-ty-dy-uh-REH-tik) hormone, which helps control body water balance through its effect on the kidneys
  • oxytocin (ahk-see-TOE-sin), which triggers the contractions of the uterus that happen during labor

The pituitary also secretes endorphins (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 (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 (thy-RAHK-sin) and triiodothyronine (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 (par-uh-THY-roydz). They release parathyroid hormone, which controls the level of calcium in the blood with the help of calcitonin (kal-suh-TOE-nin), which the thyroid makes.

Adrenal Glands: These two triangular adrenal (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 (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 (muh-DUH-luh). It makes catecholamines (kah-tuh-KO-luh-meenz), such as epinephrine (eh-puh-NEH-frun). Also called adrenaline, epinephrine increases blood pressure and heart rate when the body is under stress.

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

Reproductive Glands: The gonads are the main source of sex hormones. In boys the male gonads, or testes (TES-teez), are in the scrotum. They secrete hormones called androgens (AN-druh-junz), the most important of which is
testosterone(tess-TOSS-tuh-rone). These hormones tell a boy’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 boy’s body when it’s time to make sperm in the testes.

A girl’s gonads, the ovaries (OH-vuh-reez), are in her pelvis. They make eggs and secrete the female hormones
estrogen(ESS-truh-jen) and
progesterone(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 (PAN-kree-us) makes insulin (IN-suh-lin) and glucagon (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.

What Can Help Keep the Endocrine System Healthy?

To help keep your child’s 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 your child:

  • drinks a lot of water but is still thirsty
  • has to pee often
  • has frequent belly pain or nausea
  • is very tired or weak
  • is gaining or losing a lot of weight
  • has tremors or sweats a lot
  • is constipated
  • isn’t growing or developing as expected

Medically reviewed by: Larissa Hirsch, MD

Date reviewed: October 2018

Hormonal (endocrine) system – Better Health Channel

Summary

Read the full fact sheet

  • Endocrine glands secrete hormones straight into the bloodstream.
  • Hormones help to control many body functions, such as growth, repair and reproduction.
  • The endocrine system involves many organ systems and hormones, many of which are still being investigated and understood.

Endocrine glands make chemicals called hormones and pass them straight into the bloodstream. Hormones can be thought of as chemical messages.

From the blood stream, the hormones communicate with the body by heading towards their target cell to bring about a particular change or effect to that cell. The hormone can also create changes in the cells of surrounding tissues (paracrine effect). The endocrine system works with the nervous system and the immune system to help the body cope with different events and stresses.

This branch of medicine – relating to the study of the endocrine system – is called endocrinology and is practiced by endocrinologists. The field is rapidly expanding due to understanding of the cellular pathways that hormones stimulate and the discovery of new hormones and their actions.

Exocrine glands

An exocrine gland, unlike an endocrine gland, is a gland that secretes substances (electrolytes, proteins or enzymes) straight to a target site via ducts or tube. Some examples include:

  • Salivary glands
  • Sweat glands
  • Sebaceous glands
  • The pancreas.

The pancreas is both an endocrine and exocrine organ. It releases certain enzymes to aid in digestion delivered to the gut via the pancreatic duct. The endocrine pancreas also releases hormones such as insulin and glucagon, which are hormones predominantly related to glucose metabolism, into the blood stream.

Functions of the endocrine system

Some of the roles of the endocrine system include:

  • Growth
  • Repair
  • Sexual reproduction
  • Digestion
  • Homeostasis (constant internal balance).

How hormones work

A hormone will only act on a part of the body if it ‘fits’. A hormone can be thought of as a key, and its target site (such as an organ) has specially shaped locks on the cell walls. If the hormone fits the cell wall, then it will work.

The hormones can set off a cascade of other signaling pathways in the cell to cause an immediate effect (for instance, insulin signaling leads to a rapid uptake of glucose into muscle cells) or a more delayed effect (glucocorticoids bind to DNA elements in a cell to switch on the production of certain proteins, which takes a while to produce).

The endocrine system is a tightly regulated system that keeps the hormones and their effects at just the right level. One way this is achieved is through ‘feedback loops’. The release of hormones is regulated by other hormones, proteins or neuronal signals.

The released hormone then has its effect on other organs. This effect on the organ feeds back to the original signal to control any further hormone release. The pituitary gland is well known for its feedback loops.

Endocrine glands and organs

The main glands and organs of the endocrine system include:

  • Pituitary gland – is inside the brain. It oversees the other glands and keeps hormone levels in check. It can bring about a change in hormone production somewhere else in the system by releasing its own ‘stimulating’ hormones. The pituitary gland is also connected to the nervous system through part of the brain called the hypothalamus. The hormones released by the pituitary gland are gonadotropins (LH and FSH), growth hormone (GH), thyroid stimulating hormone (TSH), adrenocorticotropic hormone (ACTH), prolactin, antidiuretic hormone and oxytocin.
  • Thyroid gland – sits in the neck at the front of the windpipe. It releases thyroid hormone (T4 and T3) which is required for metabolism and body homeostasis. It is controlled by TSH which is produced by the pituitary gland through a feed-back loop.
  • Parathyroid gland – there are usually four parathyroid glands which lie alongside the thyroid gland. The parathyroid gland is involved in calcium, phosphate and vitamin D regulation.
  • Adrenal glands – there are two adrenal glands which sit on top of each kidney. They make a number of different hormones. The outside part of the gland (adrenal cortex) makes cortisol, aldosterone and sex hormones. The centre of the adrenal gland (adrenal medulla) makes adrenaline. Adrenaline is an example of a hormone that is under the control of the nervous system.
  • Pancreas – an organ of digestion which is inside the abdomen. It makes insulin, which controls the amount of sugar in the bloodstream. It also makes other hormones such as glucagon and somatostatin.
  • Ovaries – are inside the female pelvis. They make female sex hormones like oestrogen.
  • Testes – they hang in the male scrotal sack. They make male sex hormones like testosterone.

Other lesser known endocrine organs include:

  • Adipose tissue (fat tissue) – is recognised to be metabolically important. It releases hormones such as leptin, which affect appetite, and is also a site of oestrogen production. Insulin also acts on adipose tissue.
  • Kidneys – produce erythropoietin (EPO) which stimulates red blood cell production, produce renin which is needed for blood pressure regulation and produce the active form of Vitamin D (1–25 dihydroxy vitamin D3)
  • Gut – an increasing number of hormones in the gut are being researched and being understood to effect metabolism and appetite. Included are glucagon-like peptide 1 (GLP–1), ghrelin which stimulates appetite, and somatostatin.

Problems of the endocrine system

Numerous problems can occur in the endocrine system. These can be considered as excessive or deficient hormone production. Endocrine organs are also prone to tumours (adenomas) which can over produce hormones. Some problems of the endocrine system include:

  • Diabetes – too much sugar in the blood caused by problems with insulin production. This includes type 1 diabetes (deficiency of insulin) and type 2 diabetes (initially excessive, then deficiency, of insulin).
  • Menstruation abnormalities – irregular menstruation or lack of menstruation. Some causes of this include polycystic ovarian syndrome (PCOS), pituitary adenoma or primary ovarian failure (POF).
  • Thyroid problems – when the gland is overactive (hyperthyroidism) or underactive (hypothyroidism). Thyroid nodules are common but thyroid cancers are rare.
  • Parathyroid problems – an enlargement or one of more of the parathyroid glands can lead to high calcium levels in the blood (hypercalcemia).
  • Pituitary adenomas – these are tumours of the pituitary gland that can make too much of a certain hormone or cause deficiencies of hormones. These tumours can be small (microadenomas) or large (macroadenomas).
  • Neuro-endocrine tumours – these are rare to tumours of certain endocrine glands (usually the adrenal gland, pancreas or small bowel). These can include too much adrenaline released by the adrenal gland (pheochromocytoma), or too much hormone 5–HIAA from a carcinoid tumour which causes diarrhoea and flushing.

Where to get help

  • Your GP (doctor)
  • Australian Pituitary FoundationExternal Link Tel. 1300 331 807
  • Australian Thyroid FoundationExternal Link
  • Diabetes AustraliaExternal Link Tel. 1800 177 055
  • Healthy MaleExternal Link
  • Australian Menopause SocietyExternal Link Tel. (03) 5962 6241
  • Jean Hailes for Women’s HealthExternal Link Tel. (03) 9562 7555

This page has been produced in consultation with and approved
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What is the endocrine system – an explanation of glands and hormones

The endocrine system is a system of glands that produce and release hormones into the blood. These hormones control many of the body’s vital functions such as growth, metabolism, and reproduction.

What is the endocrine system?

The endocrine system is very complex and scientists are still learning a lot about how it works. But we do know that the circulatory system plays an important role in delivering hormones to target tissues.

The endocrine system includes many different glands. These include the pituitary gland, thyroid gland, adrenal glands, and pancreas. Each gland produces specific hormones that help regulate various bodily functions. For example, the pituitary gland produces growth hormone, which allows the body to grow and develop. The thyroid gland produces thyroxine, which helps regulate metabolism. The adrenal glands produce adrenaline, which helps mobilize the body’s resources during times of stress.

Body glands

There are many different glands in the body, each with a specific function. Endocrine glands produce hormones – chemicals that regulate the growth, metabolism and reproduction of the body.

Pituitary gland

The pituitary gland is located at the base of the brain; this gland produces growth hormone, which regulates the growth of the body. The pituitary gland is also responsible for the production of other hormones such as adrenocorticotropic hormone (ACTH), which controls the production of stress hormones in the adrenal glands. Fight or flight, the system that can make us feel stressed or anxious, is controlled by the pituitary gland.

Hypothalamus

The hypothalamus is located just below the thalamus, in the center of the brain. It produces many hormones, including corticotropin-releasing hormone (CRH), which regulates the production of stress hormones in the adrenal glands. The hypothalamus also regulates body temperature, hunger, thirst and fatigue.

Thyroid gland

The thyroid gland is located in the front of the neck, just below the vocal apparatus (larynx). It produces thyroid-stimulating hormone, which regulates the body’s metabolism. Thyroid hormone helps the body convert food into energy and plays a role in growth and development.

Parathyroid gland

The parathyroid gland is located in the neck, behind the thyroid gland. It produces parathyroid hormone, which helps regulate calcium levels in the body. Calcium is essential for many functions, including muscle contraction, nerve function, and blood clotting.

Adrenal glands

The adrenal glands sit above the kidneys and produce stress hormones such as adrenaline and cortisol. These hormones help the body respond to stressful situations.

Pancreas

The pancreas is located in the abdomen, behind the stomach. It produces insulin, a hormone that helps regulate blood sugar levels. The pancreas also produces other hormones, such as glucagon, which help regulate metabolism.

Pineal gland

The pineal gland is located in the brain, in the center of the head. It produces melatonin, a hormone that helps regulate sleep. The pineal gland also helps regulate the circadian rhythm, or the body’s internal clock.

Reproductive glands (ovaries and testes)

Ovaries and testicles are the main reproductive glands. The ovaries produce eggs that are necessary for fertilization. They also produce hormones such as estrogen and progesterone that play a role in reproduction.

The testicles produce sperm, which is necessary for fertilization. They also produce testosterone, a hormone that helps regulate male characteristics such as muscle mass and hair growth.

Hormones

Now that we have discussed the glands of the body, let’s talk about hormones. As we have already said, hormones are chemicals that regulate the growth, metabolism and reproduction of the body. They are produced by the endocrine glands and enter the bloodstream. Through the blood, hormones enter target tissues, where they bind to specific receptors. Binding of hormones to receptors causes a response in target tissues.

There are many different hormones in the body, each with a specific function. Some of the most important hormones include:

Adrenaline (stress hormone)

Adrenaline increases heart rate, blood pressure and blood sugar levels, which gives the body extra energy to cope with a stressful situation

Cortisol (stress hormone)

Cortisol helps the body respond to stress by regulating metabolism, blood sugar and immune function .

Estrogen

Estrogen regulates the menstrual cycle and promotes the development of feminine features such as breasts and hips. Estrogen also protects bone health.

Progesterone

Progesterone prepares the body for pregnancy by thickening the lining of the uterus and also plays a role in the production of breast milk.

Testosterone

Testosterone promotes the development of male qualities such as muscle mass and hair growth; it also regulates sex drive.

Thyroid hormone

Thyroid hormone regulates the body’s metabolism, which is the process of converting food into energy. It also controls the activity of the nervous system.

Insulin

Insulin regulates blood sugar by helping the body store and use glucose (sugar). Many other hormones in the body play an important role in regulating growth, metabolism, and reproduction.

Hormone imbalance

A hormonal imbalance occurs when there is too much or too little of a hormone in the body. Hormone imbalances can lead to various health problems, including infertility, obesity, and diabetes.

There are several ways to correct hormonal imbalances. One of them is hormone replacement therapy, which involves taking hormones in pill form. Another way is surgery to remove a gland that is not functioning properly. Finally, some hormonal imbalances can be treated with lifestyle changes such as diet and exercise.

Circulatory system

The circulatory system is essential for the proper functioning of the endocrine system and is responsible for transporting hormones throughout the body. Circulating blood delivers hormones to target tissues by binding to specific receptors. Binding of hormones to receptors causes a response in target tissues. Without the circulatory system, hormones would not be able to reach their target tissues and perform their functions.

There are two main types of circulation in the body: The first is systemic circulation: it carries oxygen-rich blood to the tissues of the body. Pulmonary circulation: Carries carbon dioxide-rich blood from body tissues to the lungs.

People also ask about the endocrine system

What are hormones?

Hormones are chemical molecules produced by the endocrine glands. These hormones travel through the bloodstream and bind to specific receptors on target cells. This binding elicits a response in target cells that can be anything from stimulating cell growth to regulating metabolism.

Hormones are important for many vital bodily functions, including growth, metabolism and reproduction. Imbalances in hormone levels can lead to various health problems.

What are endocrine diseases?

Endocrine disorders occur when there is an imbalance of hormones in the body. This may be due to dysfunction of one or more endocrine glands, or to problems with the hormones themselves. Common endocrine diseases include diabetes, hypothyroidism, and adrenal insufficiency. Treatment for endocrine disorders often includes medication, lifestyle changes, or surgery.

How can I help regulate my hormones?

There are some simple strategies to help you regulate your hormone levels, including being physically active, maintaining a healthy weight, eating a balanced protein diet, reducing stress through activities such as meditation or yoga, and getting enough sleep.

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ReSources

Anatomy of the endocrine system | Johns Hopkins Medicine

Endocrine system: What it is, functions and organs

Hormones and the endocrine system | Johns Hopkins Medicine

Endocrine System: What it is, Functions, Organs and Conditions

Reproductive Glands – Encyclopedia of Health – University of Rochester Medical Center

10 Natural Ways to Balance Hormones

Endocrine System – ONA Medical Association

Endocrine This system ensures the stable operation of the human body in a constantly changing environment, its protection from stress.

The endocrine system includes the following main organs: hypothalamus, pituitary gland, thyroid gland, mammary gland, adrenal glands, pancreas, ovaries (testes in men), gallbladder and appendix. ES organs are glands that provide growth, physiological development, reproductive functions of a person, as well as the course of the most important processes of balancing the activity of the whole organism under continuously changing external influences. Management of all this work and control over the correctness of its implementation is carried out in the body by hormones, which are produced by the glands of the ES. Each hormone is responsible for its own organs and functions, but works in a delicate balance with hormones produced by other glands. Depending on the function being performed at the moment, a different balance of hormones is required. Its failure causes disruption of the corresponding systems, organs, the flow of necessary reactions, which leads to the appearance of abnormalities in the body, and then diseases. Therefore, regular monitoring of hormonal levels is the key to the timely detection of violations and their curability. Another feature of ES should be noted: the interconnection and interdependence of its glands is so great that a violation found in one of the organs almost automatically means the presence of problems in others – after all, there is a hormonal failure.

Endocrine glands (EG) do not have excretory ducts, and the substances they secrete (hormones) enter directly into the blood and lymph. By sending hormones into the blood, EJs create a communication system and control the work of literally every cell in the body. Hormones provide its chemical balance, give the cells an indication of how to act, given their abilities and capabilities. The purpose of the EJ is to ensure the well-being of the whole organism, the balance in the work of internal organs, regardless of changes in the external environment, to protect the body from the destructive effects of stress.

Hypothalamus. Regulates the temperature reaction, establishes the correct ratio between heat release and heat transfer, controls the pituitary gland.

Pituitary gland. Manages the operation of the entire system. Incoming and outgoing messages are coordinated and make the ES work efficiently and harmoniously. The pituitary gland controls the body’s chemical balance by influencing most of the body’s chemical processes (for example, regulating water-salt and fat metabolism).

There is a constant need for the body to adapt to external changes, and this is also part of the task of the pituitary gland. The human body grows, wears out, and the pituitary gland is engaged in ensuring growth and repair. In addition, it provides reproductive function.

The pituitary gland performs its functions with the help of hormones that stimulate other endocrine glands. Those, in turn, secrete hormones that affect the pituitary gland itself and the nervous system. What happens in the body when the production of only one hormone is disrupted can be seen in the example of growth hormone. If it is produced more than the norm, a person becomes a victim of gigantism, if it is less than the norm, he remains a dwarf.

The pituitary gland is called the conductor of the ES, and sometimes its “brain”.

Thyroid. If the pituitary gland is the conductor of ES, then the thyroid gland (TG) is its metronome. It kind of sets the pace for all the cells of the body. The main function of the thyroid gland is to control the proper metabolism, the absorption of oxygen. It can speed up the metabolism if it increases the amount of hormones sent to the blood stream, or slow it down by reducing their amount. However, this does not happen, since its work is under the control of thyroid-stimulating hormone secreted by the pituitary gland. And that, in turn, manages the thyroid hormone, which provides feedback to the pituitary gland. That is, between the pituitary gland and the thyroid gland, there is a self-regulating mechanism of balance and control, working in a certain cycle.

Normal thyroid function promotes growth, puberty, childbearing, mental development, emotional balance, vitality.

Adrenal glands. Their bark is actually a gland, also called adrenal. It produces adrenaline, which increases vascular tone and blood pressure. The adrenal cortex affects the performance of the body, its resistance to stress. Women’s adrenal glands also help the ovaries – they also produce sex hormones. Moreover, during menopause, when the ovaries stop their production.

Pancreas. It produces insulin, which enhances the process of burning glycogen in muscles, which proceeds with the release of energy.

Gallbladder. During stress, it releases bile, as a result of which the peristalsis of the small intestine increases, the rotting masses are quickly pushed into the large intestine, into the rectum. There is an accelerated release of toxins, thereby preventing their entry into the blood.

Appendix. At the moment of stress, the release of the hormone occurs, as a result of which the peristalsis of the large intestine increases and the rotting masses are released through the rectum (often this process is called “bear disease”).

Ovaries. In the broadest sense, the ovaries provide a woman with femininity. They perform this function with the help of two main hormones: estrogen and progesterone. Progesterone promotes fertility, while estrogen provides other signs of femininity, including the complex function of the menstrual cycle. And when the ovaries reduce its secretion, menopause occurs.

Hormones. This is a Greek word meaning “I excite,” “I set into action.” These are a kind of chemical messages, ordering the actions of certain organs. The hormone does not explain to the cells what kind of work they should do, but only determines how much and how quickly it should be done. Each hormone has its own controlled organs, but circulating through the body, it affects others, having a specific and general effect.

The pituitary gland produces three main hormones: gonadotropic (stimulates the ovaries and sex glands) and mammotropic or prolactin (affects the mammary glands, promotes the formation of milk after the birth of a child) and thyrotropic.