How does the endocrine system regulate bodily functions. What are the major glands in the human body and their roles. Which disorders can affect the endocrine system. How do hormones impact growth, metabolism, and reproduction.

The Endocrine System: An Overview of Hormone Regulation

The endocrine system is a complex network of glands that produce and secrete hormones directly into the bloodstream. These chemical messengers play a crucial role in regulating various bodily functions, from growth and metabolism to reproduction and mood. Understanding the intricacies of this system is essential for comprehending how our bodies maintain homeostasis and respond to internal and external stimuli.

At its core, the endocrine system consists of several major glands, each with specific functions and hormone production capabilities. These glands work in concert to ensure proper bodily function and maintain overall health. By releasing hormones into the bloodstream, the endocrine system enables communication between distant organs and tissues, orchestrating a symphony of biological processes that keep us alive and thriving.

Key Functions of the Endocrine System

• Regulating metabolism and energy balance
• Controlling growth and development
• Managing stress responses
• Governing reproductive processes
• Maintaining electrolyte balance
• Influencing mood and cognitive function

The endocrine system’s influence extends to nearly every cell and organ in the body, making it a vital component of human physiology. Its proper functioning is essential for maintaining good health and well-being throughout life.

Major Endocrine Glands and Their Functions

The endocrine system comprises several glands, each with unique roles in hormone production and regulation. Understanding these glands and their functions provides insight into how the body maintains balance and responds to various stimuli.

Hypothalamus: The Master Controller

The hypothalamus serves as a crucial link between the nervous system and the endocrine system. Its primary function is to regulate the pituitary gland, often referred to as the “master gland” of the endocrine system. How does the hypothalamus accomplish this. By producing releasing and inhibiting hormones, the hypothalamus directs the pituitary gland to either increase or decrease its hormone production, thereby influencing a wide range of bodily functions.

Pituitary Gland: The Conductor of the Endocrine Orchestra

Located at the base of the brain, the pituitary gland is often called the “master gland” due to its far-reaching influence on other endocrine glands. This small but mighty gland produces a variety of hormones that regulate crucial bodily functions:

• Growth hormone (GH): Stimulates growth and cell reproduction
• Prolactin: Promotes milk production in breastfeeding mothers
• Adrenocorticotropic hormone (ACTH): Stimulates the adrenal glands
• Thyroid-stimulating hormone (TSH): Regulates thyroid gland function
• Follicle-stimulating hormone (FSH) and luteinizing hormone (LH): Control reproductive functions

The pituitary gland’s diverse hormone production makes it a central player in maintaining overall endocrine balance and coordinating various bodily processes.

Thyroid Gland: Metabolism’s Maestro

The butterfly-shaped thyroid gland, located in the neck, plays a crucial role in regulating metabolism, growth, and development. It produces two main hormones: thyroxine (T4) and triiodothyronine (T3). These hormones influence nearly every cell in the body, controlling how quickly the body uses energy, makes proteins, and regulates sensitivity to other hormones.

How does thyroid function impact overall health. An underactive thyroid (hypothyroidism) can lead to fatigue, weight gain, and slowed metabolism, while an overactive thyroid (hyperthyroidism) may cause rapid heartbeat, weight loss, and increased nervousness. Maintaining proper thyroid function is essential for overall well-being and energy balance.

Parathyroid Glands: Guardians of Calcium Balance

The four tiny parathyroid glands, located behind the thyroid, play a crucial role in maintaining calcium homeostasis in the body. They produce parathyroid hormone (PTH), which regulates calcium and phosphorus levels in the blood and bones. This delicate balance is essential for proper nerve and muscle function, as well as bone health.

Adrenal Glands: Stress Response Regulators

Situated atop the kidneys, the adrenal glands produce hormones that help the body respond to stress and regulate various metabolic processes. The adrenal cortex produces corticosteroids, including cortisol (the “stress hormone”) and aldosterone (which regulates sodium and potassium balance). The adrenal medulla secretes epinephrine (adrenaline) and norepinephrine, which are involved in the “fight or flight” response.

Pancreas: Blood Sugar Balancer

The pancreas serves both endocrine and exocrine functions. As an endocrine gland, it produces insulin and glucagon, two hormones crucial for regulating blood sugar levels. Insulin promotes the uptake of glucose by cells, lowering blood sugar, while glucagon stimulates the release of stored glucose, raising blood sugar. This delicate balance is essential for maintaining energy levels and overall metabolic health.

Hormones: The Chemical Messengers of the Endocrine System

Hormones are the primary means by which the endocrine system exerts its influence on the body. These chemical messengers are released by endocrine glands into the bloodstream, where they travel to target tissues and organs to elicit specific responses. Understanding the nature and function of hormones is crucial for comprehending the endocrine system’s role in maintaining bodily homeostasis.

Types of Hormones

Hormones can be broadly classified into three main categories based on their chemical structure:

1. Amino acid-derived hormones (e.g., epinephrine, norepinephrine)
2. Peptide hormones (e.g., insulin, growth hormone)
3. Steroid hormones (e.g., cortisol, estrogen, testosterone)

Each type of hormone has unique properties that influence how it is produced, transported, and received by target cells. This diversity allows the endocrine system to regulate a wide range of physiological processes with precision and specificity.

Hormone Action and Regulation

How do hormones exert their effects on target cells. Hormones typically bind to specific receptors on or within target cells, initiating a cascade of cellular responses. This process can lead to changes in gene expression, enzyme activity, or cellular metabolism, depending on the hormone and target tissue involved.

The endocrine system employs various feedback mechanisms to regulate hormone production and maintain physiological balance. Negative feedback loops, in which elevated hormone levels suppress further production, are common in many endocrine pathways. This self-regulating system helps prevent excessive hormone secretion and maintains homeostasis.

Endocrine System Disorders: When Hormones Go Awry

While the endocrine system is remarkably efficient, various disorders can disrupt its delicate balance, leading to a wide range of health issues. Understanding these disorders is crucial for early detection, proper diagnosis, and effective treatment.

Common Endocrine Disorders

• Diabetes mellitus (Type 1 and Type 2)
• Thyroid disorders (hypothyroidism, hyperthyroidism)
• Adrenal insufficiency (Addison’s disease)
• Cushing’s syndrome
• Growth hormone deficiency or excess
• Polycystic ovary syndrome (PCOS)
• Hypogonadism

Each of these disorders can have profound effects on overall health and quality of life. Early diagnosis and appropriate management are essential for mitigating their impact and preventing long-term complications.

Diabetes Mellitus: A Growing Epidemic

Diabetes mellitus, particularly Type 2 diabetes, has become increasingly prevalent worldwide. This disorder is characterized by impaired insulin production or insulin resistance, leading to elevated blood glucose levels. What are the primary risk factors for developing Type 2 diabetes. Obesity, sedentary lifestyle, and genetic predisposition are major contributors to the development of this condition.

Managing diabetes often requires a multifaceted approach, including dietary modifications, regular exercise, and, in some cases, medication or insulin therapy. Proper management is crucial for preventing complications such as cardiovascular disease, neuropathy, and kidney damage.

Thyroid Disorders: Impacting Metabolism and More

Thyroid disorders, including hypothyroidism and hyperthyroidism, can significantly impact overall health and well-being. These conditions result from either underproduction or overproduction of thyroid hormones, leading to a wide range of symptoms affecting metabolism, energy levels, and various bodily functions.

How can thyroid disorders be diagnosed and treated. Blood tests measuring thyroid hormone levels are typically used for diagnosis. Treatment options may include hormone replacement therapy for hypothyroidism or medications to suppress thyroid function in cases of hyperthyroidism. In some cases, surgical intervention may be necessary.

The Endocrine System and Aging: Hormonal Changes Over Time

As we age, the endocrine system undergoes various changes that can impact overall health and well-being. Understanding these age-related changes is crucial for maintaining hormonal balance and addressing potential health concerns throughout life.

Menopause and Andropause: Hormonal Transitions

For women, menopause marks a significant hormonal transition, typically occurring between the ages of 45 and 55. During this time, the ovaries gradually produce less estrogen and progesterone, leading to the cessation of menstrual cycles and various physical and emotional symptoms.

Men experience a more gradual decline in testosterone levels as they age, a process sometimes referred to as andropause. This decline can impact muscle mass, bone density, and sexual function, among other aspects of health.

Growth Hormone and Aging

Growth hormone production naturally declines with age, contributing to decreased muscle mass, increased body fat, and reduced bone density. While some advocate for growth hormone replacement therapy in older adults, its benefits and risks remain a topic of ongoing research and debate.

Maintaining Endocrine Health: Lifestyle Factors and Prevention

While some endocrine disorders have genetic components or arise from factors beyond our control, many aspects of endocrine health can be influenced by lifestyle choices. Adopting healthy habits can help support optimal endocrine function and reduce the risk of developing certain disorders.

Nutrition and Endocrine Health

A balanced diet rich in essential nutrients is crucial for maintaining endocrine health. Certain nutrients play particularly important roles in hormone production and function:

• Iodine: Essential for thyroid hormone production
• Vitamin D: Supports calcium absorption and bone health
• Omega-3 fatty acids: May help regulate hormone production
• Zinc: Important for insulin production and function

How can dietary choices impact endocrine health. Consuming a varied diet that includes whole grains, lean proteins, fruits, vegetables, and healthy fats can provide the necessary nutrients to support optimal endocrine function. Limiting processed foods, excessive sugar, and unhealthy fats may help reduce the risk of developing conditions like type 2 diabetes and obesity, which can impact endocrine health.

Exercise and Hormonal Balance

Regular physical activity plays a crucial role in maintaining hormonal balance and overall endocrine health. Exercise can help:

• Improve insulin sensitivity
• Regulate stress hormones
• Support healthy body composition
• Enhance thyroid function
• Boost growth hormone production

Engaging in a combination of aerobic exercise and strength training can provide comprehensive benefits for endocrine health and overall well-being.

Stress Management and Endocrine Function

Chronic stress can have significant impacts on the endocrine system, particularly on the adrenal glands and their production of stress hormones like cortisol. Implementing effective stress management techniques can help maintain hormonal balance and support overall endocrine health.

What are some effective stress management strategies. Practices such as meditation, deep breathing exercises, yoga, and regular physical activity can help reduce stress levels and promote hormonal balance. Additionally, ensuring adequate sleep and maintaining strong social connections can contribute to overall well-being and endocrine health.

The Future of Endocrine Research and Treatment

The field of endocrinology continues to evolve rapidly, with ongoing research shedding new light on the complexities of hormone function and endocrine disorders. Several exciting areas of research hold promise for improved understanding and treatment of endocrine conditions in the future.

Precision Medicine in Endocrinology

Advances in genetic testing and personalized medicine are opening new avenues for tailored treatment approaches in endocrinology. By identifying specific genetic markers associated with endocrine disorders, healthcare providers may be able to develop more targeted and effective treatment strategies for individual patients.

Artificial Intelligence and Endocrine Health

The integration of artificial intelligence (AI) and machine learning in healthcare is showing promise in the field of endocrinology. These technologies may help improve diagnostic accuracy, predict disease progression, and optimize treatment plans based on vast amounts of patient data.

How might AI impact endocrine care in the future. AI-powered systems could potentially analyze complex patterns in hormone levels, genetic data, and other health markers to provide more precise diagnoses and personalized treatment recommendations. This could lead to more effective management of endocrine disorders and improved patient outcomes.

Emerging Therapies and Treatment Modalities

Researchers are exploring innovative approaches to treating endocrine disorders, including:

• Gene therapy for genetic endocrine disorders
• Stem cell treatments for diabetes and other conditions
• Novel drug delivery systems for more efficient hormone replacement
• Bioengineered hormone analogues with improved efficacy and fewer side effects

These emerging therapies hold the potential to revolutionize the treatment of endocrine disorders, offering new hope for patients with challenging or treatment-resistant conditions.

As our understanding of the endocrine system continues to grow, so too does our ability to diagnose, treat, and prevent endocrine disorders. By staying informed about the latest developments in endocrine research and maintaining a proactive approach to endocrine health, individuals can work towards optimal hormonal balance and overall well-being throughout their lives.

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 – Histology

No cell is an island. With the emergence of multi-cellular organisms appeared a need for communication between cells to coordinate the activities of specialized tissues for the benefit of an entire organism. The endocrine system plays a major role in this process.

Now, we know that practically every organ sends signals (hormones) to other body parts to elicit biological responses that adjust the behavior of these target organs to maintain homeostasis. The heart does it, fat does it, as do the stomach and intestines.  However, this chapter covers only the glandular organs that secrete hormones as their primary function.

The “classic” endocrine glands in the human body include the pituitary, thyroid, parathyroid, adrenal 

and pineal glands. Some other glands with endocrine cells have both endocrine and non-endocrine functions. The pancreas is one of these glands, where the non-endocrine function is secreting digestive enzymes to the small intestine.

The diagram below shows the endocrine glands and their localization throughout the body. The pineal gland and the pituitary gland are located in the brain. The thyroid gland, located within the neck, wraps around the trachea. Four small, disc-shaped parathyroid glands are embedded into the posterior side of the thyroid. The adrenal glands are located on top of each kidney. The pancreas is located in the upper portion of the abdomen. In females, the two ovaries are in the pelvic cavity, while in males, the two testes are located in the scrotum.

Endocrine glands and cells are located throughout the body and play an important role in homeostasis.

The human pituitary gland is a small endocrine gland attached to the inferior surface of the brain by a thin thread of tissue called the infundibulum. The pituitary has two parts or lobes, the anterior pituitary (a.k.a adenohypophysis) and a posterior pituitary (a.k.a neurohypophysis. ) The two parts of the pituitary have different origins, are made of different tissues and look different under the microscope. Both parts have a fairly rich network of sinusoid capillaries that pick up secreted hormones.

Anterior pituitary

The anterior lobe is made of secretory epithelial cells and can be recognized by the presence of glandular epithelium. The hormone-secreting cells are arranged along the sinusoidal capillaries into cords sharply outlined by collagenous fibers.

The pituitary is frequently stained with more than hematoxylin-eosin in order to show the different types of hormone-secreting cells. The colors of the cells depend on the hormones the cell produces and stores in the secretory granules. In Masson’s trichrome stain:

The acidophils are dark red and rounded. They include cells that produce growth hormone (GH) and prolactin.

The basophils are blue and produce luteinizing hormone (LH), follicle stimulating hormone (FSH), thyroid stimulating hormone (TSH) and adrenal cortical stimulating hormone (ACTH).

The chromophobes are light orange or faded and are ACTH producing cells, or cells that have emptied their granules.

Anterior pituitary

The posterior lobe is made of the axons of hypothalamic neurons extending through the infundibulum, and pituicytes, which are the specialized glial cells. In the trichrome stain, the posterior lobe looks grayish and vacuolated. The large magenta-stained swellings are Herring bodies, the secretory granules containing either oxytocin or anti-diuretic hormone (ADH). The red-pink nuclei belong to pituicytes.

Posterior pituitary

The majority of the thyroid gland is made of spherical structures called follicles, instead of cords and clusters characteristic of the endocrine system. The central cavity of a follicle is filled with a colloid composed of thyroglobulin. Thyroglobulin is a glycoprotein that is a precursor and storage molecule for thyroid hormones. An extensive network of capillaries around follicles allows for the easy pick up of hormones by the blood.

The thyroid gland has two types of endocrine cells with different functions.

Follicular cells are the secretory (glandular) epithelial cells surrounding a cavity filled with a pink thyroglobulin. The height of the follicular cells reflects the functional state of the thyroid. The more active the cells, the taller the follicular cells. Follicular cells with normal activity are simple cuboidal; the highly active cells become columnar, the inactive cells flatten to squamous. Follicular cells produce and secrete the hormones thyroxine and triiodothyronine.

The parafollicular cells are primarily located in clusters between follicles but can also be a part of the follicular wall. Parafollicular cells are larger, oval in shape and have lighter stained cytoplasm than follicular cells. These cells secrete calcitonin.

Follicular and parafollicular cells of the thyroid gland

Parathyroid glands are small glands located on the posterior side of the thyroid. There are two types of cells in the parathyroid glands, chief cells, that secrete hormones and non-secreting oxyphil cells.

The majority of the cells are chief cells. They have clear cytoplasm and small, centrally placed, round nuclei. Cells are arranged into cords of cells surrounded by sinusoidal capillaries. Oxyphil cells are larger and intensely eosinophilic (pink) and may be found interspersed or in clusters among the chief cells. The function of the oxyphil cells is unknown.

Chief cells and oxyphil cells of the parathyroid gland

The adrenal gland is another “double origin” and double function endocrine organ. The outside layer of the triangle-shaped organ, the cortex, is made of the steroid hormone producing cells, and secretes cortisol, aldosterone and adrenal androgens. In the interior is a medulla that is part of the autonomic nervous system, and is made of the chromaffin cells that secrete catecholamines, adrenaline and noradrenaline. The adrenal gland is covered by an outer connective tissue capsule. In the center of the adrenal gland lies the large central vein.

Adrenal gland. Adrenal cortex produces steroid hormones while adrenal medulla produces catecholamines.

Adrenal cortex

Going from outside, from the connective tissue capsule, the adrenal cortex is comprised of three distinctly recognizable layers:

• • a thin zona glomerulosa
  • a wide zona fasciculata
  • a thin zona reticularis
    Layers of the adrenal cortex. 1. zona glomerulosa 2. zona fasciculata 3. zona reticularis and the medulla to the left.

The cells of the zona glomerulosa are small, with round nuclei and arranged in loops and arcades. This layer is darker in appearance due to the closely located nuclei.

Zona glomerularis

The cells of zona fasciculata are large and are arranged into columns. The nuclei are round and larger than those of the zona glomerulosa or zona reticularis. The accumulation of lipid droplets in the cytoplasm of these cells (white spots in histological preps) gives this zone a vacuolated appearance.

Zona fasciculata

The cells of zona reticularis are smaller than those of the zona fasciculata and look like a branched network. The cytoplasm may contain brown pigment and gives this zone a darker appearance. Zona reticularis borders the medulla on the inside.

Zona reticularis

Adrenal medulla

The medulla is composed of the chromaffin cells that are arranged in cords and clumps surrounded by sinusoidal capillaries. The chromaffin cells have a clear cytoplasm in hematoxylin/eosin staining, but after dichromate fixation they can appear brown due to the oxidation of the catecholamines with dichromate salts. Cells making norepinephrine stain darker than those making epinephrine.

Adrenal medulla

Pancreas has both exocrine and endocrine components. The endocrine component of the pancreas consists of the islets of Langerhans, the round masses of glandular epithelial cells appearing as nodules in the endocrine pancreas. The cells are found in irregular cords and clumps, as opposed to the neighboring, highly organized acini of the exocrine pancreas. They are surrounded by a network of capillaries. Two principal cells in the islets are the alpha cells that secrete glucagon, and the beta cells that secrete insulin. These cell types cannot be differentiated by light microscopy, and biopsy is of no use in diagnosing type 1 diabetes.

Islet of Langerhans, higher magnification.

Endocrine glands

Internal glands
secretions (from Greek endo
– inside, krino – highlight) –
are glands that do not have excretory ducts
and secrete the hormones they produce
directly into the blood, lymph and
interstitial fluid.

glands internal
secretions differ in their development,
structure, chemical composition of the emitted
hormones and effects on the body, but all
they have common anatomical and physiological
features:

– absence
excretory ducts;

– base fabric
almost all endocrine glands – glandular
epithelium;

– glands are surrounded
dense network of lymphatic and circulatory
capillaries;

– hormones,
produced in the cells of the glands, are formed
in small quantities and have a high
biological activity;

– are innervated
many nerve fibers
predominantly autonomic nervous
systems.

K
endocrine glands include:
pituitary, hypothalamus, epiphysis, thyroid
gland, parathyroid
gland,
thymus, pancreas,
adrenal glands and sex glands.

Pituitary
consists of three lobes: anterior
(adenohypophysis), intermediate and posterior
(neurohypophysis).

Front share
(adenohypophysis) secretes tropic
hormones that regulate
influence on the functions of other endocrine
glands, as well as somatotropin (hormone
growth), enhancing protein synthesis and breakdown
fat.

Newborn
somatotropin concentration 2-3 times
higher than that of the mother. Within 1 week
after birth, it decreases more than
by 50%. After 3-5 years, the level of somatotropin
in the blood is the same as in adults.

Another hormone
adenohypophysis lactotropin is registered
in high concentrations in the newborn.
During the 1st year, its concentration in
blood volume decreases and remains low until
adolescence. During the period of sexual
maturing concentration of it again
increases, and in girls it is stronger,
than boys. In adolescents, lactotropin
performs a number of important functions. In men’s
it stimulates growth in the body
prostate and seminal
bubbles. Hypersecretion of lactotropin
causes a decrease in testosterone secretion,
hypogonadism and decreased sexual
attraction. In the female body this
hormone inhibits the secretion of gonadotropins.

Also adenohypophysis
produces thyrotropin, which regulates
thyroid function. Significant
increased secretion of thyrotropin is noted
immediately after birth and before puberty
ripening. The first increase is related
with the adaptation of the newborn to new
conditions of existence. Second promotion
corresponds to hormonal changes,
including increased function of the genital
glands.

corticotropin,
regulating adrenal function
blood of a newborn is contained in such
the same concentrations as in adults
person. At the age of 10 years, its concentration
becomes two times lower and again
reaches the size of an adult
after puberty.

Gonadotropin
(follicle stimulating hormone) and
lutropin (luteinizing hormone). At
newborn concentration of these
hormones are high. During the 1st
weeks after birth, there is a sharp
decrease in these hormones. Up to 7-8 years old
age remains low. In prepubertal
period there is an increase in secretion
gonadotropins. By 14 years of concentration
their increases by 2-2.5 times compared
with 8-9 years. By the age of 18 concentration
becomes the same as in adults.

Intermediate
proportion of the pituitary gland produces
melanocyte-stimulating hormone
(intermedin), which regulates skin
pigmentation and hair pigmentation. His
concentration in the pituitary
stable as in fetal period
development and after birth.

Posterior lobe
pituitary gland (neurohypophysis) is
depot of the hormones vasopressin and oxytocin.
The content of these hormones in the blood is high
by the time of birth, and 2-22 hours after
birth, their concentration decreases sharply.
In children during the first months after
birth antidiuretic function
vasopressin is insignificant, and with age
its role in water retention in the body
increases. target organs for
oxytocin – uterus and mammary glands
just starting to react
after the end of the sexual period
maturation.

Epiphysis
produces the hormone melatonin. Gland
detected at 5-7 weeks of the period
intrauterine development. Secretion
starts at 3 months. V
infancy functional
gland activity is high. But already in
at the end of the first year of life
restructuring of its structure: decreases
number of active parenchyma cells,
blood supply is reduced. Coming from
age functional activity
epiphysis is reduced. If due to any
causes early involution
gland, then it is accompanied by more
rapid puberty.
But it should be noted that complete atrophy
epiphysis does not occur even in the deep
old age.

Thyroid
gland produces thyroid
hormones – thyroxine and triiodothyronine.
They stimulate growth and development in
intrauterine period of ontogeny.
Important for the full development of the nervous system
systems. Thyroid hormones increase
heat production, activate the exchange
proteins, fats and carbohydrates. Besides,
produced in the thyroid gland
calcitonin is a hormone that lowers
calcium content in the blood.

Concentration
thyroid hormones in the blood of newborns
higher than in adults. Within a few
days, the level of hormones in the blood decreases.
By the age of 7, secretory function is enhanced
thyroid gland. Also significant
increase in mass and secretory activity
gland occurs during puberty
maturation. Synthesis and secretion of hormones
thyroid glands depend on the sex
hormones. Sex differences in function
thyroid glands are formed as before
birth, and after it. Especially
clearly manifested during sexual
maturation.

Content
calcitonin increases with age
the highest concentration is
after 12 years. Boys 18 years of age
calcitonin is several times higher than
in children 7-10 years old.

Parathyroid
glands produce parathormone,
which together with calcitonin and
vitamin D regulates
calcium metabolism in the body. Concentration
parathyroid hormone in a newborn
to the concentration of an adult.
active iron
functions up to 4-7 years. In the period from 6 to
12 years there is a decrease in the level
parathyroid hormone in the blood. Hypofunction
manifests itself in children in an increase
excitability of nerves and muscles, in disorder
autonomic functions and formation
skeleton.

Pancreas
gland has an accumulation of cells
(Islets of Langerhans), which have
intrasecretory activity. Available
three types of cells: β-cells that produce
insulin, α-cells producing glucagon;
D-cells that form somatostatin,
inhibiting the secretion of insulin and glucagon.

Insulin reduces
glucose levels in the blood and in the liver
and muscles provides deposition
glycogen. Increases education
fat from glucose and inhibits its breakdown.
Insulin activates protein synthesis,
increases the transport of amino acids
through cell membranes.

Influenced
glucagon breaks down glycogen
liver and muscles to glucose and increase
blood glucose levels. Glucagon
stimulates the breakdown of fat in adipose tissue.

Up to 2 years old
age, the concentration of insulin in the blood
is 66% of the concentration of an adult
person. Later concentration
increases, a significant increase
noted during a period of intensive growth.

With hypofunction
β-cells develops diabetes mellitus.
In children, this disease is most often
seen from 6 to 12 years of age. Importance
in the development of diabetes mellitus
genetic predisposition and
provoking environmental factors: infectious
diseases, stress and
binge eating.

Adrenal glands
consist of two dissimilar fabrics
– cortex and medulla. The bark consists
from three zones: glomerular, secreting
mineralocorticoids; beam,
producing glucocorticoids and
reticulated, producing analogues
gonadal hormones. Main
glucocorticoid is cortisone.
Glucocorticoids affect metabolism.
Under their influence, carbohydrates are formed
from protein breakdown products. They possess
anti-inflammatory and antiallergic
action. Mineralocorticoids regulate
mineral and water metabolism in the body.
The main hormone in this group is aldosterone.
Corticosteroids are involved in
formation of secondary sexual characteristics.

medulla
adrenal glands produce norepinephrine
and adrenaline. Adrenaline speeds up the rhythm
heart rate, increases
blood pressure, increase
performance of skeletal muscles. Under
its influence increases the decay
liver glycogen. norepinephrine in general
increases blood pressure.

In the first days of life
in the blood of the newborn
low concentration of cortical hormones
adrenal glands. During the first 2
weeks functionality of the cortex
increase and secrete the same
hormone, as in adults. Secretion
corticosteroid increases in
throughout childhood and adolescence.
Thus, the greatest activity of the cortex
adrenal glands observed at age
7-8 years, then it decreases and again
increases by age 10.

It should be noted,
that glucocorticoids are not deposited,
are synthesized and released into the blood
response to corticotropin. At
children and teenagers
hypothalamic-pituitary-adrenal
the system is depleted quickly, so
ability to resist action
She has few negative factors.
The adrenal medulla in
the newborn is developed relatively
weakly. However, the activity of the sympathoadrenal
system appears immediately after birth.
From the first days of life, the child reacts
to stress stimuli.

Sex glands
presented in the male body
testes, and in the female – the ovaries.
Male sex hormones
called androgens. True male
hormone is testosterone. In the testes
produced a small amount
female sex hormones – estrogen.
the role of testosterone
is to influence the formation
sexual characteristics. female sexual
hormones are estrogens, which stimulate
growth and development of the female reproductive system
organism.

secretion of testosterone
begins at 8 weeks of fetal
development, and between the 11th and 17th
reaches adult level in weeks
men. This is due to its influence
for the implementation of genetically programmed
gender. Androgens induce differentiation
hypothalamus by male type, with their
lack of development of the hypothalamus
occurs in a feminine way. Role
own estrogens in fetal development
female is not so high, since
active participation in these processes
take maternal estrogens and analogues
sex hormones produced in
adrenal glands.

In newborns
girls during the first 5-7 days of
maternal hormones circulate in the blood.
In boys before puberty
concentration of testosterone in the blood
kept at a low level. IN
puberty hormonal
testicular activity intense
increases. High concentration
testosterone stimulates the formation
secondary sexual characteristics.

Forked
gland (thymus) is
lymphoid organ, well developed in
childhood. thymus hormones
glands are thymosins, stimulating
immunological processes. In particular,
they provide the formation of cells,
capable of specifically recognizing
antigen and immune response
reaction.

Thymus
laid on the 6th week and completely
formed by the 3rd month of intrauterine
development. In newborns it
characterized by functional maturity
and continues to develop further. But
in parallel with this in the thymus
already in the first year of life begin
develop connective tissue
fibers and adipose tissue, and with the onset
puberty she begins to be exposed
involutions. But older people also have
isolated islets of thymic parenchyma
glands play an important role in
immunological defense of the body.

Endocrine gland dysfunctions – Medcor

DESCRIPTION

Endocrine glands include the pituitary gland, thyroid gland, parathyroid glands, pancreas, adrenal glands, gonads (or gonads). The organs of internal secretion synthesize hormones, which are chemical and biological carriers of all energy, chemical, mechanical, physical, informational processes in the body. Hormones regulate the activity of enzymes – the main “builders” and “power engineers” of a living organism. Thus, they affect the entire metabolism (metabolism). Not only the activity of enzymes or enzymes, but also the rate of their synthesis depends on hormones. Previously, it was believed that hormones are synthesized only in the endocrine glands, but it is now known that a significant part of the hormones is produced in the nervous system, the mucosa of the gastrointestinal tract, and even in the heart muscle. The amount of circulating hormones depends on the rate of their synthesis, breakdown and release of their decay products. The branch of medicine that studies hormones is called endocrinology.

PARATHYROID DYSFUNCTION. HYPERPARATHIORESIS

This disease is caused by excessive secretion! parathyroid hormone. The parathyroid glands are four small ones!! the size of a pea, formations located in the immediate vicinity of the thyroid gland. Their action is to regulate calcium in the body, mainly in the bones. The hormone of this gland converts vitamin D into an active form that promotes the absorption of calcium from the digestive tract. The causes of hyperparathyroidism are unknown. Signs of the disease are not immediately noticeable. Initially, the disease proceeds secretly, and only later constipation, bloating, weight loss, loss of appetite, increased thirst and increased urination occur. As a result of the prolonged course of the disease, urolithiasis, duodenal ulcer and acute pancreatitis develop. The disease occurs at the age of 20-40 years, more often in women. Only surgical treatment is known. I also think that we should always remember the needs of the parathyroid glands and do not forget that they need vitamin D, which helps the body absorb calcium, regulates calcium-phosphorus metabolism

HYPOPARATHYROISIS

This disorder in the body is caused by insufficient function of the parathyroid glands. It usually develops after damage to the parathyroid glands during operations on the thyroid gland. Typical symptoms: attacks of muscle spasms with cramps in the fingers and feet, abdominal pain, diarrhea, spasms of the respiratory muscles (sometimes life-threatening). Often these seizures resemble an epileptic seizure. As a complication of this disease, cataracts, dry skin, deformity of the fields can act, and in children, inhibition of physical and mental development.

Treatment

During acute attacks, intravenous administration of calcium preparations is required, complete nutrition, which contains natural products rich in vitamins C, 1, A, D, group B, as well as trace elements – calcium, phosphorus, cobalt, potassium, magnesium , iodine, iron, copper, zinc

THYROID DYSFUNCTION. HYPOTHYROISIS

Hypothyroidism is an underfunction of the thyroid gland. Acute insufficiency of thyroid function associated with providing the body with thyroid hormones can be acquired and congenital. Congenital insufficiency of hormones leads to the development of a severe disease of the bones and nervous system – cretinism.

Acquired thyroid deficiency is called myxedema. It manifests itself in the form of accumulation of mucinous fluid in the tissues and cavities of the body, dryness and pallor of the skin, weakening and decreased concentration, chilliness, depression or apathy. In children, there is a slow physical development and a decrease in mental abilities. Sometimes the thyroid gland itself increases (goiter appears). The causes of acquired hypothyroidism are very different. Often this disease is observed after autoimmune diseases of the thyroid gland, with the destruction of thyroid cells. As a result, a number of complications arise: a violation of blood clotting, heart failure, a violation of respiratory processes, swelling of all tissues, anemia. In women, the monthly cycle is disturbed, in; men gradually develop impotence. The treatment will cut short in prescribing the missing thyroid hormones.

THYROID CANCER

Rare. However, after the Chernobyl disaster, the number of cases (especially among children) increased. In the early stage, the disease proceeds secretly. Treatment is usually traditional – chemotherapy, radiation, surgical treatment.

Recently, there has been an increased frequency of autoimmune inflammatory diseases of the thyroid gland, and the manifestation of these diseases is also goiter. In addition to cosmetic inconvenience in the initial stages, this disease has no other manifestations, and only the large size of the goiter can disrupt the pace of breathing, change the timbre of the voice. The development of goiter is facilitated by: smoking, taking painkillers, sulfonamides (for example, biseptol), as well as lithium preparations used in psychiatry. Treatment usually consists of restoring the balance of iodine and prescribing special hormones.