WikiDoc Resources for Endocrine system |
Articles |
---|
Most recent articles on Endocrine system Most cited articles on Endocrine system |
Media |
Powerpoint slides on Endocrine system |
Evidence Based Medicine |
Clinical Trials |
Ongoing Trials on Endocrine system at Clinical Trials.gov Trial results on Endocrine system Clinical Trials on Endocrine system at Google
|
Guidelines / Policies / Govt |
US National Guidelines Clearinghouse on Endocrine system NICE Guidance on Endocrine system
|
Books |
News |
Commentary |
Definitions |
Patient Resources / Community |
Patient resources on Endocrine system Discussion groups on Endocrine system Patient Handouts on Endocrine system Directions to Hospitals Treating Endocrine system Risk calculators and risk factors for Endocrine system
|
Healthcare Provider Resources |
Causes & Risk Factors for Endocrine system |
Continuing Medical Education (CME) |
International |
|
Business |
Experimental / Informatics |
Editors-In-Chief: C. Michael Gibson, M.S., M.D. [1] and Stephanie Fernandez, M.D. [2]
The endocrine system is an integrated system of small organs that involve the release of extracellular signaling molecules known as hormones. The endocrine system is instrumental in regulating metabolism, growth and development and puberty, tissue function, and plays a part also in mood.[1] The field of medicine that deals with disorders of endocrine glands is endocrinology, a branch of the wider field of internal medicine.
The Endocrine system is an information signal system much like the nervous system. However, the nervous system uses nerves to conduct information, whereas the endocrine system mainly uses blood vessels as information channels. Glands located in many regions of the body release into the bloodstream specific chemical messengers called hormones. Hormones regulate the many and varied functions of an organism, e.g., mood, growth and development, tissue function, and metabolism, as well as sending messages and acting on them.
The typical mode of cell signaling in the endocrine system is endocrine signaling. However, there are also other modes, i.e., paracrine, autocrine, and neuroendocrine signaling [2]. Purely neurocrine signaling between neurons, on the other hand, belongs completely to the nervous system.
A number of glands that signal each other in sequence is usually referred to as an axis, for example the Hypothalamic-pituitary-adrenal axis.
Typical endocrine glands are the pituitary, thyroid, and adrenal glands. Features of endocrine glands are, in general, their ductless nature, their vascularity, and usually the presence of intracellular vacuoles or granules storing their hormones. In contrast exocrine glands such as salivary glands, sweat glands, and glands within the gastrointestinal tract tend to be much less vascular and have ducts or a hollow lumen.
Other signaling can target the same cell.
Paracrine signaling is where the target cell is nearby.
Juxtacrine signals are transmitted along cell membranes via protein or lipid components integral to the membrane and are capable of affecting either the emitting cell or cells immediately adjacent.
Diseases of the endocrine system are common,[3] including diseases such as diabetes mellitus, thyroid disease, and obesity. Endocrine disease is characterised by dysregulated hormone release (a productive Pituitary adenoma), inappropriate response to signalling (Hypothyroidism), lack or destruction of a gland (Diabetes mellitus type 1, diminished erythropoiesis in Chronic renal failure), or structural enlargement in a critical site such as the neck (Toxic multinodular goitre). Hypofunction of endocrine glands can occur as result of loss of reserve, hyposecretion, agenesis, atrophy, or active destruction. Hyperfunction can occur as result of hypersecretion, loss of suppression, hyperplastic, or neoplastic change, or hyperstimulation.
Endocrinopathies are classified as primary, secondary, or tertiary. Primary endocrine disease inhibits the action of downstream glands. Tertiary endocrine disease is associated with dysfunction of the hypothalamus and its releasing hormones.
Cancer can occur in endocrine glands, such as the thyroid, and hormones have been implicated in signalling distant tissues to proliferate, for example the Estrogen receptor has been shown to be involved in certain breast cancers. Endocrine, Paracrine, and autocrine signalling have all been implicated in proliferation, one of the required steps of oncogenesis.[4]
This is a table of the glands of the endocrine system, and their secreted hormones
Secreted hormone | From cells | Effect |
---|---|---|
Melatonin (Primarily) | Pinealocytes | antioxidant and causes drowsiness |
Secreted hormone | Abbreviation | From cells | Effect |
---|---|---|---|
Growth hormone | GH | Somatotropes | stimulates growth and cell reproduction
Release Insulin-like growth factor 1 from liver |
Prolactin | PRL | Lactotropes | milk production in mammary glands sexual gratification after sexual acts |
Adrenocorticotropic hormone or corticotropin | ACTH | Corticotropes | synthesis of corticosteroids (glucocorticoids and androgens) in adrenocortical cells |
Lipotropin | Corticotropes | lipolysis and steroidogenesis, stimulates melanocytes to produce melanin | |
Thyroid-stimulating hormone or thyrotropin | TSH | Thyrotropes | stimulates thyroid gland to secrete thyroxine (T4) and triiodothyronine (T3) |
Follicle-stimulating hormone | FSH | Gonadotropes | In female: stimulates maturation of Graafian follicles in ovary.
In male: spermatogenesis, enhances production of androgen-binding protein by the Sertoli cells of the testes |
Luteinizing hormone | LH | Gonadotropes | In female: ovulation
In male: stimulates Leydig cell production of testosterone |
Secreted hormone | Abbreviation | From cells | Effect |
---|---|---|---|
Oxytocin | Magnocellular neurosecretory cells | Contraction of cervix and vagina
Involved in orgasm, trust between people.[5] and circadian homeostasis (body temperature, activity level, wakefulness) [6]. release breast milk | |
Vasopressin or antidiuretic hormone | AVP or ADH | Magnocellular neurosecretory cells | retention of water in kidneys
moderate vasoconstriction |
Secreted hormone | Abbreviation | From cells | Effect |
---|---|---|---|
Melanocyte-stimulating hormone | MSH | Melanotroph | melanogenesis by melanocytes in skin and hair. |
Secreted hormone | Abbreviation | From cells | Effect |
---|---|---|---|
Triiodothyronine | T3 | Thyroid epithelial cell | potent form of thyroid hormone: increase the basal metabolic rate & sensitivity to catecholamines,
affect protein synthesis |
Thyroxine or tetraiodothyronine | T4 | Thyroid epithelial cells | less active form of thyroid hormone: increase the basal metabolic rate & sensitivity to catecholamines,
affect protein synthesis |
Calcitonin | Parafollicular cells | Construct bone
reduce blood Ca2+ |
Secreted hormone | Abbreviation | From cells | Effect |
---|---|---|---|
Parathyroid hormone | PTH | Parathyroid chief cell | increase blood Ca2+: *indirectly stimulate osteoclasts
(Slightly) decrease blood phosphate: |
Secreted hormone | Abbreviation | From cells | Effect |
---|---|---|---|
Atrial-natriuretic peptide | ANP | Cardiac myocytes | Reduce blood pressure by:
reducing systemic vascular resistance, reducing blood water, sodium and fats |
Brain natriuretic peptide | BNP | Cardiac myocytes | (To a minor degree than ANP) reduce blood pressure by:
reducing systemic vascular resistance, reducing blood water, sodium and fats |
Secreted hormone | From cells | Effect |
---|---|---|
Thrombopoietin | Myocytes | stimulates megakaryocytes to produce platelets[7] |
Secreted hormone | From cells | Effect |
---|---|---|
Calcidiol (25-hydroxyvitamin D3) | Inactive form of Vitamin D3 |
Secreted hormone | From cells | Effect |
---|---|---|
Leptin (Primarily) | Adipocytes | decrease of appetite and increase of metabolism. |
Estrogens[8] (mainly Estrone) | Adipocytes |
Secreted hormone | Abbreviation | From cells | Effect |
---|---|---|---|
Gastrin (Primarily) | G cells | Secretion of gastric acid by parietal cells | |
Ghrelin | P/D1 cells | Stimulate appetite,
secretion of growth hormone from anterior pituitary gland | |
Neuropeptide Y | NPY | increased food intake and decreased physical activity | |
Secretin | S cells | Secretion of bicarbonate from liver, pancreas and duodenal Brunner's glands
Enhances effects of cholecystokinin Stops production of gastric juice | |
Somatostatin | D cells | Suppress release of gastrin, cholecystokinin (CCK), secretin, motilin, vasoactive intestinal peptide (VIP), gastric inhibitory polypeptide (GIP), enteroglucagon
Lowers rate of gastric emptying Reduces smooth muscle contractions and blood flow within the intestine [9] | |
Histamine | ECL cells | stimulate gastric acid secretion | |
Endothelin | X cells | Smooth muscle contraction of stomach [10] |
Secreted hormone | From cells | Effect |
---|---|---|
Cholecystokinin | I cells | Release of digestive enzymes from pancreas
Release of bile from gallbladder hunger suppressant |
Secreted hormone | Abbreviation | From cells | Effect |
---|---|---|---|
Insulin-like growth factor (or somatomedin) (Primarily) | IGF | Hepatocytes | insulin-like effects
regulate cell growth and development |
Angiotensinogen and angiotensin | Hepatocytes | vasoconstriction
release of aldosterone from adrenal cortex dipsogen. | |
Thrombopoietin | Hepatocytes | stimulates megakaryocytes to produce platelets[7] |
Secreted hormone | From cells | Effect |
---|---|---|
Insulin (Primarily) | ß Islet cells | Intake of glucose, glycogenesis and glycolysis in liver and muscle from blood
intake of lipids and synthesis of triglycerides in adipocytes Other anabolic effects |
Glucagon (Also Primarily) | a Islet cells | glycogenolysis and gluconeogenesis in liver
increases blood glucose level |
Somatostatin | d Islet cells | Inhibit release of insulin [11]
Inhibit release of glucagon[11] Suppress the exocrine secretory action of pancreas. |
Pancreatic polypeptide | PP cells | Unknown |
Secreted hormone | From cells | Effect |
---|---|---|
Renin (Primarily) | Juxtaglomerular cells | Activates the renin-angiotensin system by producing angiotensin I of angiotensinogen |
Erythropoietin (EPO) | Extraglomerular mesangial cells | Stimulate erythrocyte production |
Calcitriol (1,25-dihydroxyvitamin D3) | Active form of vitamin D3
Increase absorption of calcium and phosphate from gastrointestinal tract and kidneys inhibit release of PTH | |
Thrombopoietin | stimulates megakaryocytes to produce platelets[7] |
Secreted hormone | From cells | Effect |
---|---|---|
Glucocorticoids (chiefly cortisol) | zona fasciculata and zona reticularis cells | Stimulation of gluconeogenesis
Inhibition of glucose uptake in muscle and adipose tissue Mobilization of amino acids from extrahepatic tissues Stimulation of fat breakdown in adipose tissue anti-inflammatory and immunosuppressive |
Mineralocorticoids (chiefly aldosterone) | Zona glomerulosa cells | Increase blood volume by reabsorption of sodium in kidneys (primarily) |
Androgens (including DHEA and testosterone) | Zona fasciculata and Zona reticularis cells | Virilization, anabolic |
Secreted hormone | From cells | Effect |
---|---|---|
Adrenaline (epinephrine) (Primarily) | Chromaffin cells | Fight-or-flight response:
|
Noradrenaline (norepinephrine) | Chromaffin cells | Fight-or-flight response:
|
Dopamine | Chromaffin cells | Increase heart rate and blood pressure |
Enkephalin | Chromaffin cells | Regulate pain |
Secreted hormone | From cells | Effect |
---|---|---|
Androgens (chiefly testosterone) | Leydig cells | Anabolic: growth of muscle mass and strength, increased bone density, growth and strength,
Virilizing: maturation of sex organs, formation of scrotum, deepening of voice, growth of beard and axillary hair. |
Estradiol | Sertoli cells | Prevent apoptosis of germ cells[12] |
Inhibin | Sertoli cells | Inhibit production of FSH |
These originate either from the ovarian follicle or the corpus luteum.
Secreted hormone | From cells | Effect |
---|---|---|
Progesterone | Granulosa cells, theca cells | Support pregnancy[13]:
Other:
|
Androstenedione | Theca cells | Substrate for estrogen |
Estrogens (mainly estradiol) | Granulosa cells | Structural:
Protein synthesis:
Fluid balance:
Gastrointestinal tract:
Melanin:
Cancer:
Lung function: |
Inhibin | Granulosa cells | Inhibit production of FSH from anterior pituitary |
Secreted hormone | Abbreviation | From cells | Effect |
---|---|---|---|
Progesterone (Primarily) | Support pregnancy[13]:
Other effects on mother similar to ovarian follicle-progesterone | ||
Estrogens (mainly Estriol) (Also Primarily) | Effects on mother similar to ovarian follicle estrogen | ||
Human chorionic gonadotropin | HCG | Syncytiotrophoblast | promote maintenance of corpus luteum during beginning of pregnancy
Inhibit immune response, towards the human embryo. |
Human placental lactogen | HPL | Syncytiotrophoblast | increase production of insulin and IGF-1
increase insulin resistance and carbohydrate intolerance |
Inhibin | Fetal Trophoblasts | suppress FSH |
Secreted hormone | Abbreviation | From cells | Effect |
---|---|---|---|
Prolactin | PRL | Decidual cells | milk production in mammary glands |
Relaxin | Decidual cells | Unclear in humans |
Template:Organ systems
Template:Endocrine system
Template:Endocrine system intervention
ar:جهاز غدد صماء bs:Endokrini sistem bg:Ендокринна система ca:Sistema endocrí cs:Soustava žláz s vnitřní sekrecí da:Endokrine system de:Endokrines System eo:Endokrina sistemo eu:Sistema endokrino id:Sistem endokrin is:Innkirtlakerfið it:Sistema endocrino he:המערכת האנדוקרינית lv:Endokrīnā sistēma lt:Endokrininė sistema hu:Belső elválasztású mirigyek mk:Ендокрин систем nl:Endocrien systeem sk:Endokrinná sústava sl:Endokrini sistem sr:Ендокрини систем fi:Umpieritysjärjestelmä sv:Endokrina systemet th:ต่อมหมวกไต tl:Sistemang endokrin