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Glands in the body and their functions: The Endocrine System and Glands of the Human Body: Function and Disorders

What are Hormones?

Hormones are chemical messengers that are secreted directly into the blood, which carries them to organs and tissues of the body to exert their functions. There are many types of hormones that act on different aspects of bodily functions and processes. Some of these include:

  • Development and growth
  • Metabolism of food items
  • Sexual function and reproductive growth and health
  • Cognitive function and mood
  • Maintenance of body temperature and thirst

Where are they secreted from?

Hormones are secreted from the endocrine glands in the body. The glands are ductless, so hormones are secreted directly into the blood stream rather than by way of ducts. Some of the major endocrine glands in the body include:

  • Pituitary gland
  • Pineal gland
  • Thymus
  • Thyroid
  • Adrenal glands
  • Pancreas
  • Testes
  • Ovaries

These organs secrete hormone in microscopic amounts and it takes only very small amounts to bring about major changes in the body. Even a very slight excess of hormone secretion can lead to disease states, as can the slightest deficiency in a hormone.

Human body hormones. Image Credit: VectorMine / Shutterstock

Hormones and diseases

Hormone disorders are diagnosed in the laboratory as well as by clinical appearance and features. Laboratory tests can be used to test bodily fluids such as the blood, urine or saliva for hormone abnormalities.

In the case of hormone deficiency, a synthetic hormone replacement therapy may be used and in cases of excess hormone production, medications may be used to curb the effects of the hormone. For example, a person with an underactive thyroid gland or hypothyroidism may be treated with synthetic thyroxine which can be taken in the form of a pill, while a person with an overactive thyroid may be administered a drug such as propranolol to counteract the effects of the excess thyroid hormone.

How do your hormones work? – Emma BrycePlay

Further Reading

Physiology, Exocrine Gland – StatPearls

Introduction

A gland is a functional unit of cells that works together to create and release a product into a duct or directly to the bloodstream. Two principal types of glands exist: exocrine and endocrine. The key difference between the two types is that, whereas exocrine glands secrete substances into a ductal system to an epithelial surface, endocrine glands secrete products directly into the bloodstream [1]. Exocrine secretions form in the acinus, a small cluster of cells at the origination of glandular ducts. Exocrine glands subclassify into subtypes based on the method of secretion, the compound produced, or the shape of the gland.

Issues of Concern

This article will discuss:

  • Various cell types found within the exocrine gland, and their functions

  • Embryologic development of exocrine glands

  • Organ systems impacted by exocrine physiology

  • Functions of exocrine glands

  • Related clinical testing

  • Pathophysiology of exocrine glands

  • Significant clinical aspects

Cellular

Exocrine glands are comprised of an acinus and a duct with different cell types, respectively. These glands are found in many organs within the body and demonstrate a large variety in the function of their secretions.  As such, a wide range of cell types exists in exocrine glands.

While the duct functions primarily to transport glandular secretions, the acinus is responsible for the production of glandular secretions, and as such, shows more variety in cellular composition. Typical cell types within the acinus include serous, mucinous, or sebaceous.

  • Serous cells secrete an isotonic fluid that contains proteins such as enzymes. Salivary glands are made up of serous cells to a large extent [2].
  • Mucinous glands secrete mucus, a typical example being Brunner glands in the duodenum.

  • Sebaceous glands secrete sebum, an oily compound. Sebaceous glands are most prevalent in the face, scalp, groin, and armpits. Cell types can be differentiated histologically as well.  Mucous cells typically stain lighter than their serous counterparts when stained with hematoxylin and eosin.

As ducts move from the acinus toward the final target, secretions initially enter the intralobular duct. Intralobular ducts have a simple cuboidal epithelium commonly surrounded by parenchyma. Intralobular ducts drain into interlobular ducts, which are a simple columnar epithelium. The final ductal unit is the interlobar duct recognized by a stratified columnar epithelium. Connective tissue surrounds both interlobular and interlobar ducts.

Development

The initial manifestation of exocrine gland formation is epithelial budding resulting from a complex interaction between mesenchymal and epithelial cell populations [3]. This initial period of ingrowth is influenced by fibroblast growth factors, most notably FGF10 and cadherin-2 [4]. Other transcription factors that have been shown to contribute to epithelial budding include HlxB9, Isl1, LEF-1, Msx1/2, Pbx1, Pdx1, and Tbx3 [5].

Following the initial formation of the epithelial bud, ductal elongation occurs. This process undergoes mediation by a large group of molecular signals such as Netrin-1, TIMP1, amphiregulin, IGF1, and leukemia inhibitory factor [5]. Several matrix metalloproteinases (MMPs) contribute assistance with basement membrane renewal and facilitate ductal elongation [6][7]. After an initial period of ductal elongation, the exocrine gland begins to form ductal branches. NF-kappa-B is thought to play a role [8], as well as sonic hedgehog and Wnts [3]. As the duct begins to elongate, the acinus undergoes a period of cell proliferation and differentiation. Due to the large variety in exocrine gland function, the exact number of cellular signals and interactions is immense. In general, however, a large role exists for cell adhesion molecules such as laminin and cadherins [9].

Exocrine morphogenesis is a rapid process. Ductal elongation and branching typically occur in less than a week, with acini formation occurring 5 to 9 days later [10][11]. In a relatively short developmental period, exocrine glands form and can begin secreting a functional product.

Organ Systems Involved

Due to the diverse number and function of epithelial surfaces in the body, many organ systems utilize exocrine glands to carry out their respective actions. Several examples will be included here, including skin, mouth, stomach, pancreas, duodenum, and breasts. 

Skin

The skin has a variety of exocrine glands, including the eccrine sweat glands and sebaceous glands. Eccrine sweat glands are the most widespread sweat gland in the body and are present on nearly every external body surface. The sweat produced is clear with little to no oil, in contrast to sebaceous glands, also found on the skin, which secretes the more oily substance sebum.  

Salivary Glands

The salivary glands in the mouth are another example of exocrine glands and include the parotid glands, submandibular glands, and sublingual glands. While each gland has a unique mixture of serous and mucous cells, together, the salivary glands act to begin the process of food digestion while also lubricating and protecting the mucosal surfaces.

Stomach

The stomach holds multiple types of exocrine glands that include pyloric glands, cardiac glands, and fundic glands. These glands incorporate many different cell types, including parietal cells, chief cells, and G cells. Together they regulate the gastric pH, release enzymes to breakdown food products to a digestible form, and assist with the absorption of necessary vitamins and minerals.  

Pancreas

The pancreas has both an endocrine and an exocrine function. The exocrine pancreas assists in food digestion by releasing a secretion rich in bicarbonate, which helps to neutralize the acidic environment created in the stomach. The secretion also includes digestive enzymes.

Duodenum

Brunner glands are present in the duodenum of the small intestine. These exocrine glands are submucosal and produce a mucous product that protects the duodenum from acid released from the stomach. The alkaline nature of the secretion also activates intestinal enzymes to assist with food breakdown and absorption.

Breast

The mammary gland is one of the most well-known examples of an exocrine gland found in the breast. Mammary glands produce milk rich in nutrients that also provides passive immunity to a baby’s immune system.

Function

The specific function of exocrine glands within the body varies by location and organ system. However, the primary role is to create a secretion which subsequently gets released through a ductal system onto an epithelial surface. Examples include secretions that assist in food digestion, mucosal protection, thermoregulation, lubrication, and nutrition.

Mechanism

The three mechanisms by which exocrine glands release their secretions include merocrine, apocrine, and holocrine.

  • Merocrine glands are the most common subtype. By definition, merocrine gland secretions exit the cell via exocytosis. In this method of secretion, there is no cell damage. An example of merocrine secretion is the eccrine sweat gland. 

  • Apocrine glands, in contrast, form buds of the membrane which break off into the duct, losing part of the cellular membrane in the process. A well-known apocrine gland is the breastmilk-producing mammary gland. 

  • The final subtype of excretion is holocrine, in which the cellular membrane ruptures to release its product into the duct. Sebaceous glands are a representation of holocrine secretion.

Related Testing

In general, testing for an individual exocrine gland function is not performed. However, dysfunction of exocrine glands can create a wide range of clinical manifestations.

Imaging may be performed to confirm a diagnosis of blocked glands. Sialolithiasis refers to instances where a stone becomes lodged within the salivary gland or duct, and sialoadenitis refers to inflammation of the gland. CT and ultrasound are effective methods of identifying and localizing stones [12].

The liver itself acts as an exocrine gland when creating and excreting bile to be stored in the gallbladder, awaiting expulsion and release through the pancreatic duct into the duodenum. Obstruction, at any point in this pathway, can cause cholecystitis due to inflammation and dysfunction of the gallbladder. Ultrasound is the initial diagnostic test to diagnose cholecystitis [13].

In cystic fibrosis, sodium and chloride are not reabsorbed within the sweat duct due to a dysfunctional CFTR protein, resulting in abnormally salty skin. The sweat chloride test is the primary test for the diagnosis of cystic fibrosis [14].

Pancreatic insufficiency occurs when the exocrine glands of the pancreas are no longer able to produce the digestive enzymes necessary for food breakdown in the small intestine. Common etiologies include chronic pancreatitis, cystic fibrosis, and hereditary hemochromatosis. Several methods can be used to evaluate the function of the exocrine pancreas. Fat malabsorption can lead to deficiencies in fat-soluble vitamins A, D, E, and K. Thus, vitamin levels can be used to estimate pancreatic function [15]. Fecal elastase-1 testing is another method with relatively high specificity and sensitivity. Low levels of fecal elastase-1 indicate a poorly functioning exocrine pancreas [16]. The most sensitive diagnostic method for exocrine pancreatic insufficiency, however, is utilizing direct pancreatic function tests such as the cholecystokinin (CCK) or secretin stimulation test [17].

Pathophysiology

Sjogren Syndrome

Sjogren’s syndrome is commonly associated with rheumatoid arthritis and other rheumatic diseases. The syndrome is an autoimmune disorder that demonstrates decreased lacrimal and salivary gland function that can also have associated systemic symptoms [18][19]. The disease is characterized by eye and mouth dryness due to the gland dysfunction.  Due to mouth dryness, patients with Sjogren syndrome show increased rates of oral candidiasis and dental caries [18][20]. 

Cystic Fibrosis

Cystic fibrosis is an autosomal recessive disease that causes impaired chloride transport due to a mutation of the CFTR protein.  Because CFTR is involved in the production of sweat, mucus, and digestive fluids, the mutation causes a direct effect on exocrine gland secretions.  Indeed, approximately 90% of infants born with cystic fibrosis will develop pancreatic insufficiency by one year of age [21].

Acne vulgaris

The prevalence of acne is an estimated 35 to 90% in adolescents [22]. The disorder affects the pilosebaceous unit, of which sebaceous glands are an example. The pathogenesis is multifactorial and often involves hyperkeratinization of the follicle, increased sebum production, and proliferation of Propionibacterium acnes with associated inflammation. As sebum accumulates, an open comedo forms, also known as a white head. Hyperkeratinization and increased sebum production lead to clogging of the pores of the pilosebaceous unit. As the lipids within sebum oxidize, the follicular orifice opens, forming an open comedo, or blackhead.

Treatment for acne largely depends on the severity of inflammatory symptoms, but topical retinoids are usually the first-line treatment, although antimicrobial agents are an additional option for refractory cases [23]. For severe cases of nodulocystic acne or for patients who have failed treatment with systemic antibiotics, oral isotretinoin the therapeutic choice [24].

Clinical Significance

The exocrine gland can be found in many organs and serves a wide variety of functions within the body. Due to this fact, an understanding of the physiology of exocrine glands is essential for healthcare workers. Exocrine glands play a key role in the physiology of many organ systems from the skin to the pancreas, providing the body with a method to release secretions containing proteins, mucus, and other products to epithelial surfaces around the body. Owing to their varied and essential roles, the dysfunction of exocrine glands is associated with diseases as wide-ranging as acne vulgaris to Sjogren syndrome.

References

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Witty JP, Wright JH, Matrisian LM. Matrix metalloproteinases are expressed during ductal and alveolar mammary morphogenesis, and misregulation of stromelysin-1 in transgenic mice induces unscheduled alveolar development. Mol Biol Cell. 1995 Oct;6(10):1287-303. [PMC free article: PMC301288] [PubMed: 8573787]
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Thomas WW, Douglas JE, Rassekh CH. Accuracy of Ultrasonography and Computed Tomography in the Evaluation of Patients Undergoing Sialendoscopy for Sialolithiasis. Otolaryngol Head Neck Surg. 2017 May;156(5):834-839. [PubMed: 28457224]
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Shea JA, Berlin JA, Escarce JJ, Clarke JR, Kinosian BP, Cabana MD, Tsai WW, Horangic N, Malet PF, Schwartz JS. Revised estimates of diagnostic test sensitivity and specificity in suspected biliary tract disease. Arch Intern Med. 1994 Nov 28;154(22):2573-81. [PubMed: 7979854]
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Endocrine Glands and Hormones – PMF IAS

Endocrine Glands and Hormones – Hypothalamus, Pituitary Gland, Pineal Gland, Thyroid Gland, Parathyroid Gland, Thymus, Adrenal Gland, Pancreas, Testis, Ovary, Mechanism of Hormone Action.

Source: NCERT Science Textbooks Class 6-12.

  • Endocrine glands lack ducts and are hence, called ductless glands. Their secretions are called hormones.
  • Hormone is a chemical produced by endocrine glands and released into the blood and transported to a distantly located target organ.
  • Hormones are non-nutrient chemicals which act as intercellular messengers and are produced in trace amounts.
  • Invertebrates possess very simple endocrine systems with few hormones whereas a large number of chemicals act as hormones and provide coordination in the vertebrates. The human endocrine system is described here.
  • The endocrine glands and hormone producing diffused tissues/cells located in different parts of our body constitute the endocrine system. Pituitary, pineal, thyroid, adrenal, pancreas, parathyroid, thymus and gonads (testis in males and ovary in females) are the organized endocrine bodies in our body.
  • In addition to these, some other organs, e.g., gastrointestinal tract, liver, kidney, heart also produce hormones.
  • A brief account of the structure and functions of all major endocrine glands and hypothalamus of the human body is given in the following sections.
  • Hypothalamus is the part of the forebrain and it regulates a wide spectrum of body functions.
  • It contains several groups of neurosecretory cells called nuclei which produce hormones.
  • These hormones regulate the synthesis and secretion of pituitary hormones.
  • However, the hormones produced by hypothalamus are of two types, the releasing hormones (which stimulate secretion of pituitary hormones) and the inhibiting hormones (which inhibit secretions of pituitary hormones).
  • For example a hypothalamic hormone called Gonadotrophin releasing hormone (GnRH) stimulates the pituitary synthesis and release of gonadotrophins.
  • On the other hand, somatostatin from the hypothalamus inhibits the release of growth hormone from the pituitary.
  • These hormones originating in the hypothalamic neurons, pass through axons and are released from their nerve endings. These hormones reach the pituitary gland through a portal circulatory system and regulate the functions of the anterior pituitary. The posterior pituitary is under the direct neural regulation of the hypothalamus.
  • The pituitary gland is located in a bony cavity called sella tursica and is attached to hypothalamus by a stalk.
  • It is divided anatomically into an adenohypophysis and a neurohypophysis.
  • Adenohypophysis consists of two portions, pars distalis and pars intermedia.
  • The pars distalis region of pituitary, commonly called anterior pituitary, produces
  1. Growth Hormone (GH),
  2. Prolactin (PRL),
  3. Thyroid Stimulating Hormone (TSH),
  4. Adrenocorticotrophic Hormone (ACTH),
  5. Luteinizing Hormone (LH) and
  6. Follicle Stimulating Hormone (FSH).
  • Pars intermedia secretes only one hormone called Melanocyte Stimulating Hormone (MSH).
  • However, in humans, the pars intermedia is almost merged with pars distalis.
  • Neurohypophysis (pars nervosa) also known as posterior pituitary, stores and releases two hormones called oxytocin and vasopressin, which are actually synthesised by the hypothalamus and are transported axonally to neurohypophysis.
  • Over-secretion of GH stimulates abnormal growth of the body leading to gigantism and low secretion of GH results in stunted growth resulting in pituitary dwarfism.
  • Prolactin regulates the growth of the mammary glands and formation of milk in them.
  • TSH stimulates the synthesis and secretion of thyroid hormones from the thyroid gland.
  • ACTH stimulates the synthesis and secretion of steroid hormones called glucocorticoids from the adrenal cortex.
  • LH and FSH stimulate gonadal activity and hence are called gonadotrophins.
  • In males, LH stimulates the synthesis and secretion of hormones called androgens from testis. In males, FSH and androgens regulate spermatogenesis.
  • In females, LH induces ovulation of fully mature follicles (graafian follicles) and maintains the corpus luteum, formed from the remnants of the graafian follicles after ovulation. FSH stimulates growth and development of the ovarian follicles in females.
  • MSH acts on the melanocytes (melanin containing cells) and regulates pigmentation of the skin.
  • Oxytocin acts on the smooth muscles of our body and stimulates their contraction. In females, it stimulates a vigorous contraction of uterus at the time of child birth, and milk ejection from the mammary gland.
  • Vasopressin acts mainly at the kidney and stimulates resorption of water and electrolytes by the distal tubules and thereby reduces loss of water through urine (diuresis). Hence, it is also called as Anti-Diuretic Hormone (ADH).
  • The pineal gland is located on the dorsal side of forebrain.
  • Pineal secretes a hormone called melatonin.
  • Melatonin plays a very important role in the regulation of a 24-hour (diurnal) rhythm of our body.
  • For example, it helps in maintaining the normal rhythms of sleep-wake cycle, body temperature.
  • In addition, melatonin also influences metabolism, pigmentation, the menstrual cycle as well as our defense capability.
  • The thyroid gland is composed of two lobes which are located on either side of the trachea.
  • Both the lobes are interconnected with a thin flap of connective tissue called isthmus.
  • The thyroid gland is composed of follicles and stromal tissues. Each thyroid follicle is composed of follicular cells, enclosing a cavity. These follicular cells synthesize two hormones, tetraiodothyronine or thyroxine (T4) and triiodothyronine (T3).
  • Iodine is essential for the normal rate of hormone synthesis in the thyroid. Deficiency of iodine in our diet results in hypothyroidism and enlargement of the thyroid gland, commonly called goitre.
  • Hypothyroidism during pregnancy causes defective development and maturation of the growing baby leading to stunted growth (cretinism), mental retardation, low intelligence quotient, abnormal skin, deaf-mutism, etc.
  • In adult women, hypothyroidism may cause menstrual cycle to become irregular.
  • Due to cancer of the thyroid gland or due to development of nodules of the thyroid glands, the rate of synthesis and secretion of the thyroid hormones is increased to abnormal high levels leading to a condition called hyperthyroidism which adversely affects the body physiology.
  • Thyroid hormones play an important role in the regulation of the basal metabolic rate.
  • These hormones also support the process of red blood cell formation.
  • Thyroid hormones control the metabolism of carbohydrates, proteins and fats.
  • Maintenance of water and electrolyte balance is also influenced by thyroid hormones.
  • Thyroid gland also secretes a protein hormone called Thyrocalcitonin (TCT) which regulates the blood calcium levels.
  • In humans, four parathyroid glands are present on the back side of the thyroid gland, one pair each in the two lobes of the thyroid gland.
  • The parathyroid glands secrete a peptide hormone called Parathyroid Hormone (PTH). The secretion of PTH is regulated by the circulating levels of calcium ions. Parathyroid hormone (PTH) increases the Ca2+ levels in the blood.
  • PTH acts on bones and stimulates the process of bone resorption (dissolution/ demineralisation).
  • PTH also stimulates reabsorption of Ca2+ by the renal tubules and increases Ca2+ absorption from the digested food.
  • It is, thus, clear that PTH is a Hypercalcemic Hormone, i.e., it increases the blood Ca2+ levels.
  • Along with TCT, it plays a significant role in calcium balance in the body.
  • The thymus gland is a lobular structure located between lungs behind sternum on the ventral side of aorta.
  • The thymus plays a major role in the development of the immune system.
  • This gland secretes the peptide hormones called Thymosins.
  • Thymosins play a major role in the differentiation of T-lymphocytes, which provide cell-mediated immunity.
  • In addition, thymosins also promote production of antibodies to provide humoral immunity.
  • Thymus is degenerated in old individuals resulting in a decreased production of thymosins. As a result, the immune responses of old persons become weak.
  • Our body has one pair of adrenal glands, one at the anterior part of each kidney. The gland is composed of two types of tissues. The centrally located tissue is called the adrenal medulla, and outside this lies the adrenal cortex.
  • The adrenal medulla secretes two hormones called adrenaline or epinephrine and noradrenaline or norepinephrine. These are commonly called as catecholamines.
  • Adrenaline and noradrenaline are rapidly secreted in response to stress of any kind and during emergency situations and are called emergency hormones or hormones of Fight or Flight.
  • These hormones increase alertness, pupilary dilation, piloerection (raising of hairs), sweating etc.
  • Both the hormones increase the heartbeat, the strength of heart contraction and the rate of respiration.
  • Catecholamines also stimulate the breakdown of glycogen resulting in an increased concentration of glucose in blood.
  • In addition, they also stimulate the breakdown of lipids and proteins.
  • The adrenal cortex secretes many hormones, commonly called as corticoids. The corticoids, which are involved in carbohydrate metabolism are called glucocorticoids. In our body, cortisol is the main glucocorticoid.
  • Corticoids, which regulate the balance of water and electrolytes in our body are called mineralocorticoids. Aldosterone is the main mineralocorticoid in our body.
  • Glucocorticoids stimulate gluconeogenesis, lipolysis and proteolysis; and inhibit cellular uptake and utilisation of amino acids.
  • Cortisol is also involved in maintaining the cardio-vascular system as well as the kidney functions.
  • Glucocorticoids, particularly cortisol, produces anti-inflammatory reactions and suppresses the immune response.
  • Cortisol stimulates the RBC production.
  • Aldosterone acts mainly at the renal tubules and stimulates the reabsorption of Na+ and water and excretion of K+ and phosphate ions. Thus, aldosterone helps in the maintenance of electrolytes, body fluid volume, osmotic pressure and blood pressure.
  • Small amounts of androgenic steroids are also secreted by the adrenal cortex which play a role in the growth of axial hair, pubic hair and facial hair during puberty.
  • Pancreas is a composite gland which acts as both exocrine and endocrine gland.
  • The endocrine pancreas consists of ‘Islets of Langerhans’. There are about 1 to 2 million Islets of Langerhans in a normal human pancreas representing only 1 to 2 per cent of the pancreatic tissue.
  • The two main types of cells in the Islet of Langerhans are called a-cells and p-cells. The a-cells secrete a hormone called glucagon, while the p-cells secrete INSULIN.
  • Glucagon is a peptide hormone, and plays an important role in maintaining the normal blood glucose levels. Glucagon acts mainly on the liver cells (hepatocytes) and stimulates glycogenolysis resulting in an increased blood sugar (hyperglycemia).
  • In addition, this hormone stimulates the process of gluconeogenesis which also contributes to hyperglycemia. Glucagon reduces the cellular glucose uptake and utilisation. Thus, glucagon is a hyperglycemic hormone.
  • Insulin is a peptide hormone, which plays a major role in the regulation of glucose homeostasis. Insulin acts mainly on hepatocytes and adipocytes (cells of adipose tissue), and enhances cellular glucose uptake and utilisation. As a result, there is a rapid movement of glucose from blood to hepatocytes and adipocytes resulting in decreased blood glucose levels (hypoglycemia).
  • Insulin also stimulates conversion of glucose to glycogen (glycogenesis) in the target cells. The glucose homeostasis in blood is thus maintained jointly by the two – insulin and glucagons.
  • Prolonged hyperglycemia leads to a complex disorder called diabetes mellitus which is associated with loss of glucose through urine and formation of harmful compounds known as ketone bodies. Diabetic patients are successfully treated with insulin therapy.
  • A pair of testis is present in the scrotal sac (outside abdomen) of male individuals. Testis performs dual functions as a primary sex organ as well as an endocrine gland.
  • Testis is composed of seminiferous tubules and stromal or interstitial tissue. The Leydig cells or interstitial cells, which are present in the intertubular spaces produce a group of hormones called androgens mainly testosterone.
  • Androgens regulate the development, maturation and functions of the male accessory sex organs like epididymis, vas deferens, seminal vesicles, prostate gland, urethra etc.
  • These hormones stimulate muscular growth, growth of facial and axillary hair, aggressiveness, low pitch of voice etc.
  • Androgens play a major stimulatory role in the process of spermatogenesis (formation of spermatozoa).
  • Androgens act on the central neural system and influence the male sexual behavior (libido).
  • These hormones produce anabolic (synthetic) effects on protein and carbohydrate metabolism.
  • Females have a pair of ovaries located in the abdomen. Ovary is the primary female sex organ which produces one ovum during each menstrual cycle. In addition, ovary also produces two groups of steroid hormones called estrogen and progesterone.
  • Ovary is composed of ovarian follicles and stromal tissues. The estrogen is synthesized and secreted mainly by the growing ovarian follicles. After ovulation, the ruptured follicle is converted to a structure called corpus luteum, which secretes mainly progesterone.
  • Estrogens produce wide ranging actions such as stimulation of growth and activities of female secondary sex organs, development of growing ovarian follicles, appearance of female secondary sex characters (e.g., high pitch of voice, etc.), mammary gland development. Estrogens also regulate female sexual behavior.
  • Progesterone supports pregnancy. Progesterone also acts on the mammary glands and stimulates the formation of alveoli (sac-like structures which store milk) and milk secretion.
  • As mentioned earlier, hormones are also secreted by some tissues which are not endocrine glands. For example, the atrial wall of our heart secretes a very important peptide hormone called Atrial Natriuretic Factor (ANF), which decreases blood pressure. When blood pressure is increased, ANF is secreted which causes dilation of the blood vessels. This reduces the blood pressure.
  • The juxtaglomerular cells of kidney produce a peptide hormone called erythropoietin which stimulates Erythropoiesis (formation of RBC).
  • Endocrine cells present in different parts of the gastro-intestinal tract secrete four major peptide hormones, namely Gastrin, Secretin, Cholecystokinin (CCK) and Gastric Inhibitory Peptide (GIP).
  • Gastrin acts on the gastric glands and stimulates the secretion of hydrochloric acid and pepsinogen.
  • Secretin acts on the exocrine pancreas and stimulates secretion of water and bicarbonate ions.
  • CCK acts on both pancreas and gall bladder and stimulates the secretion of pancreatic enzymes and bile juice, respectively.
  • GIP inhibits gastric secretion and motility.
  • Several other non-endocrine tissues secrete hormones called growth factors. These factors are essential for the normal growth of tissues and their repairing/regeneration.
  • Hormones produce their effects on target tissues by binding to specific proteins called hormone receptors located in the target tissues only.
  • Hormone receptors present on the cell membrane of the target cells are called membrane-bound receptors and the receptors present inside the target cell are called intracellular receptors, mostly nuclear receptors (present in the nucleus).
  • Binding of a hormone to its receptor leads to the formation of a hormone-receptor complex. Each receptor is specific to one hormone only and hence receptors are specific.
  • Hormone-Receptor complex formation leads to certain biochemical changes in the target tissue. Target tissue metabolism and hence physiological functions are regulated by hormones.
  • Hormones which interact with membrane-bound receptors normally do not enter the target cell, but generate second messengers which in turn regulate cellular metabolism.
  • Hormones which interact with intracellular receptors (e.g., steroid hormones, iodothyronines, etc.) mostly regulate gene expression or chromosome function by the interaction of hormone-receptor complex with the genome. Cumulative biochemical actions result in physiological and developmental effects.

On the basis of their chemical nature, hormones can be divided into groups:

  1. peptide, polypeptide, protein hormones (e.g., insulin, glucagon, pituitary hormones, hypothalamic hormones, etc.)
  2. steroids (e.g., cortisol, testosterone, estradiol and progesterone)
  3. iodothyronines (thyroid hormones)
  4. amino-acid derivatives (e.g., epinephrine).
  • There are special chemicals which act as hormones and provide chemical coordination, integration and regulation in the human body.
  • These hormones regulate metabolism, growth and development of our organs, the endocrine glands or certain cells.
  • The endocrine system is composed of hypothalamus, pituitary and pineal, thyroid, adrenal, pancreas, parathyroid, thymus and gonads (testis and ovary). In addition to these, some other organs, e.g., gastrointestinal tract, kidney, heart etc., also produce hormones.
  • The pituitary gland is divided into three major parts, which are called as pars distalis, pars intermedia and pars nervosa.
  • Pars distalis produces six trophic hormones. Pars intermedia secretes only one hormone, while pars nervosa (neurohypophysis) secretes two hormones.
  • The pituitary hormones regulate the growth and development of somatic tissues and activities of peripheral endocrine glands.
  • Pineal gland secretes melatonin, which plays a very important role in the regulation of 24-hour (diurnal) rhythms of our body (e.g., rhythms of sleep and state of being awake, body temperature, etc.).
  • The thyroid gland hormones play an important role in the regulation of the basal metabolic rate, development and maturation of the central neural system, erythropoiesis, metabolism of carbohydrates, proteins and fats, menstrual cycle.
  • Another thyroid hormone, i.e., thyrocalcitonin regulates calcium levels in our blood by decreasing it.
  • The parathyroid glands secrete parathyroid hormone (PTH) which increases the blood Ca2+ levels and plays a major role in calcium homeostasis.
  • Thyroid and adrenals secrete their hormones when they receive orders from the pituitary through its hormones.
  • Metamorphosis in insects is controlled by insect hormones. In a frog, it is controlled by thyroxine, the hormone produced by thyroid. Thyroxine production requires the presence of iodine in water. If the water in which the tadpoles are growing does not contain sufficient iodine, the tadpoles cannot become adults.
  • The thymus gland secretes thymosins which play a major role in the differentiation of T-lymphocytes, which provide cell-mediated immunity. In addition, thymosins also increase the production of antibodies to provide humoral immunity.
  • Adrenal glands secrete hormones which maintain the correct salt balance in the blood.
  • The adrenal gland is composed of the centrally located adrenal medulla and the outer adrenal cortex. The adrenal medulla secretes epinephrine and norepinephrine. These hormones increase alertness, pupilary dilation, piloerection, sweating, heart beat, strength of heart contraction, rate of respiration, glycogenolysis, lipolysis, proteolysis.
  • The adrenal cortex secretes glucocorticoids and mineralocorticoids. Glucocorticoids stimulate gluconeogenesis, lipolysis, proteolysis, erythropoiesis, cardio-vascular system, blood pressure, and glomerular filtration rate and inhibit inflammatory reactions by suppressing the immune response.
  • Mineralocorticoids regulate water and electrolyte contents of the body. The endocrine pancreas secretes glucagon and insulin.
  • Glucagon stimulates glycogenolysis and gluconeogenesis resulting in hyperglycemia. Insulin stimulates cellular glucose uptake and utilisation, and glycogenesis resulting in hypoglycemia. Insulin deficiency and/or insulin resistance result in a disease called diabetes mellitus.
  • The testis secretes androgens, which stimulate the development, maturation and functions of the male accessory sex organs, appearance of the male secondary sex characters, spermatogenesis, male sexual behaviour, anabolic pathways and erythropoiesis.
  • The ovary secretes estrogen and progesterone. Estrogen stimulates growth and development of female accessory sex organs and secondary sex characters. Progesterone plays a major role in the maintenance of pregnancy as well as in mammary gland development and lactation.
  • The atrial wall of the heart produces atrial natriuretic factor which decreases the blood pressure. Kidney produces erythropoietin which stimulates erythropoiesis.
  • The gastrointestinal tract secretes gastrin, secretin, cholecystokinin and gastric inhibitory peptide. These hormones regulate the secretion of digestive juices and help in digestion.

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Possible new organ may have been found in throat: Tubarial salivary glands

But that’s exactly what a group of scientists from the Netherlands believe. They said they have discovered a pair of previously overlooked glands that are hidden away in our skulls where the nasal cavity and the throat meet.

The medical researchers first came across the body part, which they propose naming tubarial glands, during a scan designed to look for tumorous growths. The scientists then looked at scans of the head and neck of a further 100 individuals they were treating for prostate cancer and dissected two cadavers — one male and one female. They all had a set.

The discovery was “thrilling” but the authors were “a bit skeptical” at first, said the study’s lead author Matthijs H. Valstar, a surgeon in the department of head and neck oncology and surgery at The Netherlands Cancer Institute.

“We thought it wasn’t possible to discover this in 2020,” Valstar said. “It’s important it’s replicated and it should be done with different series of patients. It’s important to have confirmation of new medical findings.”

The glands cannot be seen with conventional methods of medical imaging like ultrasound, CT scans (computerized topography) or MRI (magnetic resonance imaging), the study authors said.

The “unknown entity” was only identified when the doctors were using an advanced and new type of scan called PSMA PET/CT that has been used to detect the spread of prostate cancer. PSMA PET is shorthand for prostate-specific membrane antigen imaging using positron emission tomography.

Salivary glands show up clearly on this highly sensitive kind of imaging.

“People have three sets of large salivary glands, but not there,” said study author Wouter Vogel, a radiation oncologist at The Netherlands Cancer Institute, in a news statement in May. “As far as we knew, the only salivary or mucous glands in the nasopharynx are microscopically small, and up to 1000 are evenly spread out throughout the mucosa. So, imagine our surprise when we found these.”

Many great scientific discoveries “come as a surprise — an incidental finding,” said Joy Reidenberg, a professor of anatomy at the Icahn School of Medicine at Mount Sinai in New York City, who wasn’t involved in the study.

“Luckily, these researchers were tuned into the data, and were anatomically savvy enough to note the unusual brightness in a region that was not thought to contain any salivary glands,” Reidenberg added via email. “As the famous (late French biologist) Louis Pasteur once said: ‘Chance favors the prepared mind.'”

New organ?

It was a matter of debate whether the tubarial glands were a completely new organ or could be considered part of the salivary gland organ system, the study added.

“These findings support the identification of the tubarial glands as a new anatomical and functional entity,” said the study, which published in the journal Radiotherapy and Oncology.

The glands could be newly discovered, “but it is difficult to exclude that these might represent groups of minor salivary glands,” said Dr. Valerie Fitzhugh, the interim chair of pathology at Rutgers New Jersey Medical School and Rutgers Robert Wood Johnson Medical School. Fitzhugh wasn’t involved in the study.

Because the study concentrated on a small number of patients who were mostly male and used specific rather than standard tests, she added, examination of more women and healthier patients would allow for better data.

Overall, there is “still much to learn about the human body,” Fitzhugh said, “and technology is allowing us to make these discoveries. This might be the first of some exciting discoveries within the body.”

No matter how the glands are described, the authors said their discovery had clinical implications, especially for patients with head and neck cancer, including tumors in the throat or tongue. Radiotherapy can damage salivary glands, which can lead to dry mouth and trouble swallowing, speaking and eating.

“For most patients, it should technically be possible to avoid delivering radiation to this newly discovered location of the salivary gland system in the same way we try to spare known glands,” Vogel said.

“Our next step is to find out how we can best spare these new glands and in which patients. If we can do this, patients may experience less side effects which will benefit their overall quality of life after treatment.”

Neuroscience Resources for Kids – Body System Interaction

SYSTEM FUNCTION ASSOCIATED ORGANS INTERACTION WITH THE
NERVOUS SYSTEM
Skeletal
System

The skeletal system makes up the
framework of the body and allows us to move when our muscles contract.
It stores minerals (e.g. calcium, phosphorous) and
releases them into the body when they are needed. The skeletal system
also protects internal organs and produces blood cells.
Bones (e.g., skull, vertebrae)
  • Bones provide calcium that is essential for the proper
    functioning of the nervous system.
  • The skull protects the brain from injury.
  • The vertebrae protect the spinal cord from
    injury.
  • Sensory receptors in joints between bones send signals about body
    position to the brain.
  • The brain regulates the position of bones by controlling muscles.
Cardiovascular System

The cardiovascular system delivers oxygen, hormones,
nutrients and white blood cells around the body by pumping blood, and it
removes waste products.
Heart, blood vessels
  • Endothelial cells maintain the blood-brain
    barrier.
  • Baroreceptors send information to the brain about blood pressure.
  • Cerebrospinal fluid drains into the venous
    blood supply.
  • The brain regulates heart rate and blood pressure.
Muscular
System

Different types of muscles enable motion, generate heat to
maintain body temperature, move food through digestive tract and
contract the heart.
Muscles (smooth, skeletal and cardiac muscles)
  • Receptors in
    muscles provide the brain with information about body position and
    movement.
  • The brain controls the contraction of skeletal muscle.
  • The nervous system regulates the speed at which food moves through the
    digestive
    tract.
Endocrine
System

The endocrine system secretes hormones into blood and other
body fluids. These chemicals are important for metabolism,
growth, water and mineral balance, and the response to stress.
Pineal body, pituitary gland, hypothalamus, thyroid,
parathyroid, heart, adrenal gland, kidney, pancreas, stomach, intestines,
ovary
  • Hormones provide feedback to the brain to affect
    neural processing.
  • Reproductive hormones affect the development of the nervous system.
  • The hypothalamus controls the pituitary gland and other endocrine
    glands.
Lymphatic
System

The lymphatic system protects the body from infection. Adenoid, tonsils, thymus, lymph nodes, spleen
  • The brain can stimulate defense mechanisms against
    infection.
Respiratory System

The respiratory system supplies oxygen to the blood and
removes carbon dioxide.
Lungs, larynx, pharynx, trachea, bronchi
  • The brain monitors respiratory volume and blood gas levels.
  • The brain regulates respiratory rate.
Digestive
System

The digestive system stores and digests foods, transfers
nutrients to the body, eliminates waste and absorbs water.
Stomach, esophagus, salivary glands, liver,
gallbladder, pancreas, intestines
  • Digestive processes provide the building blocks for some
    neurotransmitters.
  • The autonomic nervous system controls the tone of the digestive tract.
  • The brain controls drinking and feeding behavior.
  • The brain controls muscles for eating and elimination.
  • The digestive system sends sensory information to the brain.
Reproductive System

The reproductive system is responsible for producing
new life.
Testes, vas deferens, prostate gland, ovary, fallopian
tubes, uterus, cervix
  • Reproductive hormones affect brain development and
    sexual behavior.
  • The brain controls mating behavior.
Urinary
System

The urinary system eliminates waste products and maintains
water balance and chemical balance.
Bladder, urethra, kidney
  • The bladder sends sensory information to the brain.
  • The brain controls urination.
Integumentary System

The integumentary system reduces water loss, contains
receptors that respond to touch, regulates body temperature, and protects
the inside of the body from damage.
Skin, hair
  • Receptors in skin send sensory information to the
    brain.
  • The autonomic nervous system regulates peripheral blood flow and
    sweat glands.
  • Nerves control muscles connected to hair follicles.

Types of Human Glands, Their Secretion, Function With Diagram PDF

Glands are organs in the body that synthesize substances like hormones and release them into the bloodstream or inside the body cavities or on the outer surface. Depending upon the way they secrete the substances, glands are classified as:

  1. Exocrine glands
  2. Endocrine glands
  3. Mixed glands

Understand the Digestive System too.

Human Endocrine Glands

  • They Secrete into blood flowing through them, so as to let the secretion function at distant parts of the body from the gland.
  • The endocrine system is a collection of glands that work interdependently and produce hormones.
  • The endocrine glands secrete chemicals known as hormones.
  • Hormones are non-nutrient chemicals which act as intracellular messengers and are produced in trace amounts.
  • Example: Pineal Gland, Pituitary Gland, Pancreas, Ovaries, Testes, Thyroid Gland, Parathyroid Gland, Hypothalamus, and Adrenal Glands.

Learn about Biomolecules in Cell here.

Human Exocrine Glands

  • Exocrine secrete into a location or region of the body through a duct and their secretions are called enzymes mostly, while some are nonenzymes.
  • Example: Sweat Glands, Salivary Glands, Mammary Gland, Ceruminous Gland, Lacrimal Gland, Mucous Gland.
  • They perform the following functions:
    • Regulate body temperature
    • Lubrication
    • Lactation
    • Helps in the digestion
    • Helps in reproduction

Human Mixed Glands

  • A gland that is both exocrine and endocrine.
  • Organs like the pancreas and liver secrete products — bile and pancreatic juice– into the gastrointestinal tract through a series of ducts, and endocrine because they secrete other substances directly into the bloodstream.

Points to Remember

  • Hypothalamus contains several groups of neurosecretory cells called nuclei which produce hormones.
  • Hypothalamus produces two types of hormones:-
    1. Releasing Hormones
    2. Inhibiting Hormones

Learn all about Cell here.

Glands and Their Secretions

Here’s a list of glands in the human body and their functions

Glands Location Secretions
Pituitary Gland

(Hypophysis)

Base of the Brain
  • Thyroid-stimulating hormone (TSH)
  • Adrenocorticotropic hormone (ACTH)
  • Gonadotropins Follicle-stimulating hormone (FSH)
  • Luteinizing hormone (LH)
  • Growth hormone (GH)
  • Prolactin, melanocyte-stimulating hormone (MSH)
  • Antidiuretic hormone (ADH) Vasopressin
  • Oxytocin
Anterior Pituitary

(Adenohypophysis)

Posterior Gland

(Neurohypophysis)

Thyroid Gland Anterior to the trachea (two lobes)
  • Thyroxine (T4)
  • Triiodothyronine (T3)
Parathyroid gland Lies on the dorsal surface of the thyroid gland (4 glands – 2 pairs)
Adrenal glands Top of each kidney (2 sections – medulla is inner and 2 cortex surrounds medulla)
  • Cortex secretes corticosteroids (Glucocorticoids and Mineralocorticoids)
  • Small amounts of androgen, estrogen, and progestin
Pancreas Left of, and behind the Stomach. (Exocrine and Endocrine gland)
  • Exocrine secretes digestive enzymes into the duodenum.
  • Endocrine has cell clusters called Islet of Langerhans.
  • Alpha islet cells produce glucagons. Beta cells secrete insulin
Liver In the abdominal cavity beneath the diaphragm, and above the stomach, right kidney, and intestines
  • Largest gland in the human body
  • Secretes Bile
Pineal Gland Near to the center of the brain between the left and right hemisphere Produces Melatonin
Thymus Gland Beneath the breastbone near the heart Produces T cells (Thymus-Derived Cells)

Check out the DNA and RNA structure here.

So, this is all about the Types of Glands in Humans. Get some practice of the same on our free Testbook App. Download Now!

Types of Glands in Humans FAQs

Q.1  What are the 3 types of glands?

Ans.1

Depending upon the way they secrete the substances, glands are classified as Exocrine glands, Endocrine glands and Mixed glands.

Q.2 What is the largest endocrine gland?

Ans.2

The pancreas is the largest endocrine gland.

Q.3  Which gland is known as the master gland?

Ans.3

The pituitary gland is called the master gland because it controls the functions of many of the other endocrine glands.

Q.4  What triggers sweat glands?

Ans.4

Combination of internal body temperature and mean skin temperature triggers sweat glands.

Q.5 Which glands are found in the skin?

Ans.5

Sweat glands and Sebaceous glands are found in the skin

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Integumentary System – Science NetLinks

Introduction

The integumentary system consists of the skin, hair, nails, glands, and nerves. Its main function is to act as a barrier to protect the body from the outside world. It also functions to retain body fluids, protect against disease, eliminate waste products, and regulate body temperature. In order to do these things, the integumentary system works with all the other systems of your body, each of which has a role to play in maintaining the internal conditions that a human body needs to function properly.


Functions of the Integumentary System

The integumentary system has many functions, most of which are involved in protecting you and regulating your body’s internal functions in a variety of ways:

  • Protects the body’s internal living tissues and organs
  • Protects against invasion by infectious organisms
  • Protects the body from dehydration
  • Protects the body against abrupt changes in temperature
  • Helps dispose of waste materials
  • Acts as a receptor for touch, pressure, pain, heat, and cold
  • Stores water and fat

How does the integumentary system work with other systems?

Your body is a complicated system that consists of many subsystems that help to keep it functioning properly. These subsystems serve a variety of purposes and require needed materials to function properly, as well as means of communicating information to other parts of the body. Thus, the skin and other parts of the integumentary system work with other systems in your body to maintain and support the conditions that your cells, tissues, and organs need to function properly.

The skin is one of the first defense mechanisms in your immune system.  Tiny glands in the skin secrete oils that enhance the barrier function of the skin. Immune cells live in the skin and provide the first line of defense against infections. 

By helping to synthesize and absorb vitamin D, the integumentary system works with the digestive system to encourage the uptake of calcium from our diet.  This substance enters the bloodstream though the capillary networks in the skin. Healthy functioning of your skin also is related to the digestive system because the digestion and assimilation of dietary fats and oils are essential for the body to be able to make the protective oils for the skin and hair.

The integumentary system also works closely with the circulatory system and the surface capillaries through your body. Because certain substances can enter the bloodstream through the capillary networks in the skin, patches can be used to deliver medications in this manner for conditions ranging from heart problems (nitroglycerin) to smoking cessation (nicotine patches).

The skin also is important in helping to regulate your body temperature. If you are too hot or too cold, your brain sends nerve impulses to the skin, which has three ways to either increase or decrease heat loss from the body’s surface: hairs on the skin trap more warmth if they are standing up, and less if they are lying flat; glands under the skin secrete sweat onto the surface of the skin in order to increase heat loss by evaporation if the body is too hot; capillaries near the surface can open when your body needs to cool off and close when you need to conserve heat.

Your skin plays a vital role in your body as regards the sense of touch. The nervous system depends on neurons embedded in your skin to sense the outside world. It processes input from your senses, including touch, and initiates actions based on those inputs. For example, when you stub your toe, nerve cells in the foot send signals up the leg, through the spinal cord, and up into the brain. The nerve cell connections in the brain sense these signals as pain.

As well as interacting with the body systems as explained above, the integumentary system also contributes to numerous physiological processes, especially those involved in the regulation of the body’s internal environment so as to maintain a stable condition. An example is provided by the way that the skin helps in temperature regulation by changes in the pattern of blood supply to the skin and by sweating, as mentioned above.

90,000 Parathyroid glands: structure, function

For the smooth functioning of the human body, it is important that all vital processes are constant – homeostasis. It is provided by metabolic processes, “orchestrators” of which are hormones, enzymes, neurotransmitters. The importance of the organs producing these biologically active substances can hardly be overestimated, since a failure in the functioning of any of them can lead to an imbalance in the general balance in the body. One of these key links in metabolism are the parathyroid (parathyroid) glands.

Where are the parathyroid glands in humans?

For a long time, doctors did not suspect the existence of this organ. Only at the end of the 19th century, the Swedish scientist Ivar Sandstrom discovered new endocrine glands in the human body.

The parathyroid glands consist of a dense outer shell and glandular cells located inside. Usually, two to six pairs of such small lenticular formations are located on the back of the thyroid gland.However, the place of their localization can be the thymus gland, the esophagus wall, and the neurovascular bundle, which is suitable for the thyroid gland.

This variability in the number and locations complicates the detection of these glands during instrumental diagnostics and surgical intervention.

What are the parathyroid glands for? What are their functions?

“Small and daring” – this is how you can characterize the importance of these endocrine glands. Despite their modest size (up to 8 mm in length and 3-4 mm in width), their functioning significantly affects the work of the nervous, musculoskeletal, cardiovascular systems.

The main task of the parathyroid glands is the production of a hormone that regulates the amount of calcium in the blood. Due to the presence of special receptors, the glands react to changes in the content of this element in the blood and, in accordance with the obtained values, change the rate of release of the hormone into the blood.

Maintaining calcium balance is extremely important for the body, since calcium ions provide the process of transmitting impulses through nerve cells and muscle tissue contraction.In addition, calcium is one of the components of the blood coagulation system, and also promotes the activation of the action of a number of enzymes.

The hormone of the parathyroid glands is called parathyroid, or, in other words, parathyroid hormone. It increases the amount of calcium ions in the blood in three different ways.

1. Under the influence of parathyroid hormone, vitamin D is activated in the kidneys, followed by the formation of calcitriol. Calcitriol, in turn, improves the absorption of calcium from food in the intestinal lumen.For this mechanism of action of parathyroid hormone to be realized, a sufficient level of vitamin D in the body is required.

2. The increase in the concentration of calcium ions in the blood is also due to the activation of its absorption from the primary urine in the kidneys.

3. Under the action of parathyroid hormone, the activity of osteoclasts – cells located in the bone tissue and destroying it – increases. The calcium released during this enters the bloodstream. As a result of this process, the concentration of calcium ions in the blood increases.If parathyroid hormone is produced more than normal, the process of destruction of bone tissue begins to prevail over its formation. Because of this, the bone loses strength and becomes fragile, and this can lead to fractures.

To regulate phosphorus-calcium metabolism in the body, another hormone is formed that acts opposite to parathyroid hormone. This is calcitonin. It is produced by the thyroid gland and a number of other organs. Thanks to its production, the level of calcium in the blood decreases and the activity of osteoblasts is stimulated – another type of bone tissue cells, which, unlike osteoclasts, do not destroy, but form new bone tissue.

How is the dysfunction of the parathyroid glands manifested?

Dysfunction of the glands leads to an excess or deficiency of calcium ions in the blood. If the production of parathyroid hormone decreases, the person has signs such as fragility and hair loss, splitting of nails and damage to the enamel of the teeth, peeling and dry skin, muscle pain. Patients may complain of irritability, headaches, mood swings, convulsions. The syndrome (a complex of symptoms), which develops due to insufficient function of the parathyroid glands, is called “hypoparathyroidism”.

An increase in parathyroid hormone production is accompanied by kidney problems (stone formation, development of nephrocalcinosis), increased blood pressure (hypertension), pain in joints and bones. The skeleton becomes fragile: bones can break with any movement. Patients complain of memory impairment, general weakness, an unstable emotional state, as well as an upset of the gastrointestinal tract – loss of appetite, vomiting, heartburn, colic. The pathological condition arising from the excessive production of parathyroid hormone is called “hyperparathyroidism”.

Primary hyperparathyroidism can develop due to neoplasms of the parathyroid gland – adenoma or cancer. Secondary hyperparathyroidism develops as a result of prolonged stimulation of the parathyroid glands, observed with chronic vitamin D deficiency (for example, in residents of the northern regions), unbalanced nutrition (insufficient intake of calcium from food), with malabsorption syndrome (impaired absorption in the intestine, including calcium) and after resection of the stomach.

The presence of the above symptoms, as well as doubts about the normal functioning of the parathyroid glands, is a good reason to seek the advice of a therapist or endocrinologist and undergo an examination.

Diagnostics of diseases of the parathyroid glands in SINEVO

Important to remember!
The information in this section cannot be used for self-diagnosis and self-medication. In case of pain or other exacerbation of the disease, diagnostic tests should be prescribed only by the attending physician. For a diagnosis and correct prescription of treatment, you should contact your doctor.

The parathyroid glands , located on the surface of the thyroid gland, maintain the balance of calcium in the blood through the production of parahormones.Calcium is involved in the formation of bone tissue, is responsible for muscle contraction, ensures the transmission of nerve impulses and the work of the heart. In diseases of the parathyroid glands, there is a decrease (hypoparathyroidism) or an increase (hyperparathyroidism) of their functions.

Hypoparathyroidism – a disease in which an insufficient amount of the parathyroid hormone is produced. This leads to a decrease in calcium in the blood, which contributes to the growth of neuromuscular arousal.

Often, hypoparathyroidism develops when the parathyroid glands are damaged or removed during surgery on the thyroid gland, as well as in inflammatory diseases of the parathyroid glands and in the process of hemorrhage with a neck injury. Hypoparathyroidism can also appear as a result of a decrease in the level of vitamin D in the body, impaired absorption of calcium in the intestine, poisoning of the body with lead and carbon monoxide, and exposure to radiation.

Symptoms

The first signal of the disease is muscle cramps. Tingling sensations and spasms appear in the limbs. These symptoms are aggravated by hypothermia, overheating, physical activity, during infectious diseases and stress. Over time, painful cramps appear, possibly numbness of the arms and legs, and the development of muscle atrophy. With a long course of the disease, weakness, irritability, depression and memory impairment appear. Headache, heart palpitations, sweating, abdominal pain and diarrhea appear. Inflammatory eye diseases and cataracts are common.In chronic hypoparathyroidism, teeth are destroyed, hair falls out, the skin becomes dry, and brittle nails increase. Long-term calcium deficiency can lead to stunted growth and mental development in children.

With hyperparathyroidism , an excess amount of the hormone of the parathyroid glands is produced. An excess of parathyrin leads to an increase in calcium in the blood and a decrease in its content in bone tissue, as a result of which the tendency to bone fractures increases.

Hyperparathyroidism can develop with an enlargement, adenoma or cancer of the parathyroid glands, and can also be the result of other diseases that disrupt the functions of the parathyroid glands (long-term calcium deficiency, severe vitamin D deficiency and chronic renal failure).

The first symptoms of the disease are poor health and fatigue for no apparent reason, muscle weakness, loss of teeth and hair. A decrease in calcium in bone tissue leads to a decrease in its strength and softening, bones become fragile and can easily break with normal movements. Radiculitis and frequent back pain occur. Stomach pains, nausea and vomiting appear. The growth of calcium in the blood can contribute to damage to the vessels of the heart, the development of hypertension and angina pectoris attacks, the occurrence of urolithiasis.Increased urination, urine becomes whitish. Possible development of stomach ulcers.

When the first signals of parathyroid disease appear, consult your doctor . It is necessary to promptly make an accurate diagnosis and prescribe effective treatment in order to prevent serious complications.

Where to get tested

To determine the functional activity of the parathyroid glands , the medical laboratory “Sinevo” recommends the following tests:

  1. The content of calcium in the blood. The level increases with hyperparathyroidism, decreases with hypoparathyroidism.
  2. The content of ionized calcium in the blood. An increase in the index in hyperparathyroidism, a decrease in hypoparathyroidism.
  3. Calcium content in urine. Increased concentration in hyperparathyroidism, decreased in hypoparathyroidism.
  4. Parathyroid hormone. The indicator increases with hyperparathyroidism, decreases with hypoparathyroidism.
  5. Osteocalcin. Characterizes changes in bone tissue. The content increases with decreasing bone density.

Female hormones, their effect on appearance, health and mood.

Hormones! Throughout life – from puberty to menopause, and before and after – they affect a woman’s mood, appearance, weight, sex drive, and more. If the effects of female hormones are, for some reason, inconsistent and complicating life, you can influence a more balanced hormone distribution by changing your lifestyle.Sometimes hormone therapy is required. Explains Gita Erta, endocrinologist of “Veselības center 4”.

HOW DO FEMALE HORMONES AFFECT WELL-BEING DURING A CYCLE?

During the cycle, hormones are involved that are produced by the hypothalamus, the pituitary gland – these endocrine organs are located in the brain, so we can say that to a large extent the woman’s menstrual cycle regulates what happens in the head, as well as the ovaries.

ESTROGENS AND PROGESTERONE

These are the most well-known female hormones, which are mainly produced by the ovaries and which directly affect a woman’s sexual and reproductive health.These hormones provide femininity, but their main physiological task is to ensure the possibility of fertilization of the egg and its attachment in the uterus.

In the first part of the menstrual cycle , estrogens dominate, making a woman more sexually attractive. Estrogens stimulate the sympathetic nervous system, so a woman is more active, easier to have a relationship. The skin becomes rosier (blood flow to the skin improves) and healthier. Breasts enlarge under the influence of estrogens, as estrogens have little effect on fluid retention.If all other hormones work in a balanced way, a woman has a great mood, increased libido, especially before ovulation.

In the second phase of the cycle progesterone dominates. Due to the activation of the parasympathetic nervous system, a woman becomes more active, passive – the goal of nature is to preserve a possible pregnancy. Progesterone reduces edema, has a slight diuretic effect, and reduces estrogen receptors in both the breast and uterus.

At the end of cycle , estrogen levels drop sharply, causing a new period.Nature has provided for women of reproductive age the opportunity to become pregnant every month. Therefore, the woman’s body is like a plant for the production of hormones, where during this period of time everything is subordinated to the creation of children.

FEMALE HORMONE IMBALANCE

Female hormone imbalance usually manifests itself as menstrual irregularities, there may be increased bloating, unpleasant breast tenderness, irregular bleeding, mood changes, weight gain, etc.

If the body produces too much estrogen or there is a deficiency of progesterone , causing a relative excess of estrogen, the woman may become unproductively hyperactive and nervous.An imbalance in hormones can cause severe premenstrual syndrome, which is characterized by painful and swollen breasts, bloating, low pain threshold, and increased menstrual bleeding.

If estrogen is low , fatigue is often observed, depression may begin, even cognitive impairment (memory impairment), libido decreases. Clinical symptoms: hot flashes with increased sweating – especially at night, as in menopause, sagging breasts, changes in the menstrual cycle, skin and mucous membranes become dry, etc.

It is the imbalance of female hormones that causes PMS or premenstrual syndrome characteristic of a woman. Sudden changes in mood and unpleasant physical sensations – headache, indomitable appetite and the like – should not be taken as normal before menstruation, these are PMS symptoms. If PMS regularly bothers you, you need to see a doctor.

WHEN TO TAKE HORMONE TESTS?

They should be taken if there are complaints.

  • In the case of pronounced PMS in the second phase of the cycle, the level of estrogen and progesterone is determined, sometimes hormone control is required both in the first and in the second phase of the cycle.The doctor assesses not only the rate of the level of each specific hormone in accordance with a certain age and day of the cycle, but also the general picture.
  • If a woman fails to become pregnant , the level of so-called male hormones is also determined and other specific tests are done, for example, the level of anti-Müllerian hormone, which shows ovarian reserves or the woman’s reproductive potential. It happens that already at the age of 30, the level of this hormone is lower than at the norm at the age of 70. If in such a situation a woman wants a child, she needs a donor egg, because, most likely, genetics and lifestyle have led to the inability to conceive a child naturally.
  • A relatively common diagnosis in our time is polycystic ovary syndrome . It is characterized by an increased concentration of male hormones – testosterone and androstenedione in the blood, as well as an increased level of LH (luteinizing hormone). The higher the LH level, the greater the risk of infertility.
THE IMPORTANCE OF LIFESTYLE IN THE BALANCE OF HORMONES

For hormones to function according to their function, both heredity and lifestyle are equally important.

  • Smoking poses great risks to a woman’s health, especially with regard to reproductive health, and is incompatible with planning pregnancy.
  • Being physically active and getting enough sleep not only ensures a normal metabolism, but also contributes to resistance to excessive stress. PMS and other cycle disorders can occur due to overload, lack of sleep, insufficient physical activity, or insufficient, unbalanced diet.Intense emotional stress decreases the synthesis of estrogen and progesterone.
  • Power supply is also of great importance. A diet with enough protein and healthy fatty acids promotes the synthesis of estrogen and progesterone, and sugar and other fast carbohydrates understand it. The optimal diet for the synthesis of female hormones would be a paleo diet containing sufficient amounts of meat and fish, which provide the body with a large number of amino acids, which is rich in fresh vegetables and fruits.
  • Excessive obsession with losing weight can lead to the cessation of menstruation, as there is a deficiency of female hormones. Women with anorexia are not only unhealthy thin, but also pale skin, brittle hair and nails, they change the shape of their breasts, since the level of estrogen is low, like in menopause. If there is obesity, there are too many estrogens, so a woman can become nervous, overly anxious, the risk of developing type 2 diabetes mellitus, various cancers (breast, ovarian, endometrial cancer), etc., increases significantly.
OTHER HORMONES ENSURING WELL-BEING AND HEALTH

In a woman’s body, the endocrine glands secrete not only hormones necessary for reproductive function, but many others. Let’s talk only about some of the most important ones.

TESTOSTERONE

Every woman needs a certain amount of testosterone, which is known as the male hormone. It promotes sexuality, activity, muscle and bone strength, poise, and cognitive function.If too much of this hormone is released, the appearance of increased hairiness on the face and body is observed, but at the same time hair loss, problems with the skin of the face may arise – acne may appear, the tone of the voice may change. Then it is clear that the hormone imbalance is to blame, which needs to be treated.

OXYTOCIN

It is a hormone that has a great impact on overall health. Oxytocin is mainly released during pleasant sensations, so this needs to be taken care of.If you like water procedures, you need to accept them, if you like good books, you need to read them. Touching almost everyone causes pleasant sensations, therefore, massage is recommended especially in times of bad mood. The release of oxytocin leads to vasodilation, including coronary or heart vessels, lowering blood pressure, increasing libido, accelerating orgasm, and also promotes wound healing, reduces pain, helps muscles relax, and stimulates anabolism.

INSULIN

An important hormone produced by the pancreas.If you are overweight, so-called insulin resistance develops. In this situation, the cells become less sensitive to insulin, so the pancreas has to produce much more hormone. For a while, the pancreas can do this, but then the exhaustion phase sets in, when an elevated glucose level is detected in the laboratory. Fortunately, insulin levels during pre-diabetes can be regulated by lifestyle changes – choosing a diet plan that reduces excess weight, ensuring enough physical activity to burn the extra calories from carbohydrates.At the same time, lifestyle changes will also balance female hormones.

CORTISOL

A hormone that the body produces too much in situations of prolonged stress. This leads to cravings for sweets and changes the metabolism, which contributes to obesity. To avoid secreting too much of this hormone, you need to balance your lifestyle. You need to get enough sleep regularly (every night you need to sleep about eight hours), exercise (in moderation at least five times a week), eat healthy, sufficient food, but not too much.This all trains resistance to excessive stress or distress.

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Hypothyroidism and Hyperthyroidism: Symptoms and Differences

Hypothyroidism and Hyperthyroidism.

These diseases are serious pathologies of the thyroid gland, which disrupt not only the work of this organ, but also other systems of the body. Diseases differ from each other, therefore it is very important to correctly recognize the disease in order to correctly prescribe therapy and eliminate the symptoms of the disorder.

Hypothyroidism

A condition of the thyroid gland in which there is a decrease in the production of hormones.

The reasons for this ailment may be:

  • • Removal of part of an organ;
  • • Autoimmune damage;
  • • Inability to assimilate iodine;
  • • Genetic disorder.

When the thyroid gland is healthy, it provides the body with a certain amount of secretion. If part of the gland due to illness does not participate in synthesis, then the hormones produced become less.

In case of autoimmune damage, immune cells attack the organ, thereby destroying thyrocytes. This negatively affects the functioning of the organ, which leads to disorders of the thyroid gland.

In congenital disorders, enzymes that are involved in protein synthesis have a defect, due to which iodine is not completely absorbed. This is the reason that the hormones are defective (not functioning properly).

There are three forms of violation. The first is caused by a disease of the organ. The second is in violation of the activity of the pituitary gland.The third form is associated with the activity of the hypothalamus.

Symptoms

The primary stage of hypothyroidism occurs in almost every person, however, a person usually does not know about the pathology (due to the absence of symptoms). At the first stage of the process, there may be a decrease in mood, apathy, and decreased performance. Against the background of strass, in which modern man usually finds himself, such symptoms are not alarming. at the end of the first stage, swelling appears on the face, dryness and peeling of the skin, changes in speech (several tones lower), hearing deteriorates, joint pains, chest discomfort, muscle weakness occur.The list of symptoms is very wide, when they appear, you must consult a doctor for diagnosis.

Hyperthyroidism

Hyperthyroidism is the opposite of hypothyroidism. The symptoms of the disease are very different, as is the mechanism for the development of the disease. It is based on a hyperfunction of the thyroid gland, in simple terms – it produces too many hormones. When they enter the bloodstream in excess, they cause symptoms of poisoning, and the metabolism accelerates several times.

Thyrotoxicosis is a complex of symptoms associated with a serious health disorder.

The reasons for this ailment may be:

  • • Long-term use of hormonal drugs;
  • • Various abnormalities of the thyroid gland;
  • • Excess iodine;
  • • Other reasons.

When hormonal agents are prescribed to you, you must strictly follow all recommendations for use and dosage, otherwise you can enter your body into a state of artificial hyperthyroidism. Cancer of the gland, diffuse toxic goiter and Plummer’s disorder also provoke excessive synthesis of hormones.

Among other reasons, it should be noted: oncological damage to the ovaries, pituitary gland, side effects of drugs. Depression, stress, pregnancy contribute to rejection.

Symptoms

Unlike hypothyroidism, symptoms of hyperthyroidism are noticeable from the very beginning. These are excitability, aggressiveness, mood swings. There are other signs: distracted attention, sleep disturbance, susceptibility to panic. When palpating, an enlargement of the gland is observed, which often causes difficulty in swallowing.

Differences hypo from hyperthyroidism:

  • • Increased heart rate, increased heart rate;
  • • Visual impairment;
  • • Weight loss with good appetite;
  • • Interruptions in the menstrual cycle;
  • • Sweating.

Against the background of intoxication, the body is trying to get rid of an excess of a dangerous substance. The heartbeat increases, the eyeball increases in volume (it becomes difficult to rotate, and tears also appear).

Due to the acceleration of metabolism, the absorption of nutrients is faster, so a person loses weight, even when eating in the usual way. For women, this often translates into difficulties in conception or termination of pregnancy.

Hyperthyroidism and hypothyroidism are interconnected – they can replace each other as different stages of the autoimmune process.


Transition between states


As we have already mentioned, a transition from one state to another is possible.A situation is often observed when hyperthyroidism turns into hypofunction (after increased production of hormones, their production is slowed down). Over the course of a person’s life, a person can suffer several different diseases of the thyroid gland.