The endocrine system is a group of glands that work together and secrete many types of different hormones that regulate Homeostasis. The field of study 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. Hormones regulate many functions of an organism, including mood, growth and development, tissue function, and metabolism. [edit] Types of signaling 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.[1] Purely neurocrine signaling between neurons, on the other hand, belongs completely to the nervous system. [edit] Endocrine The endocrine system is made up of a series of ductless glands that produce chemical messages called hormones 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. Also controls metabolism in our body system. [edit] Autocrine Other signaling can target the same cell, or other cells.[citation needed] [edit] Paracrine Paracrine signaling is where the target cell is nearby.[citation needed] [edit] Juxtacrine 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.[citation needed] [edit] Table of endocrine glands and secreted hormones discovered This is a table of the glands of the endocrine system, and their secreted hormones. Oxytocin and anti-diuretic hormone are not secreted in the posterior lobe, merely stored. | Secreted hormone | Abbreviation | From cells | Effect | | Parathyroid hormone | PTH | Parathyroid chief cell | Calcium: - Stimulates Ca2+ release from bone, thereby increasing blood Ca2+
- Stimulates osteoclasts, thus breaking down bone
- Stimulates Ca2+ reabsorption in kidney
- Stimulates activated vitamin D production in kidney
Phosphate: - Stimulates PO4= release from bones, thereby increasing blood PO4=
- Inhibits PO4= reabsorption in kidney, so more PO4= is excreted
- Overall, small net drop in serum PO4=
| | Secreted hormone | From cells | Effect | | Calcidiol (25-hydroxyvitamin D3) | | Inactive form of Vitamin D3 | [edit] Diseases Disability-adjusted life year for endocrine disorders per 100,000 inhabitants in 2002. [13] no data less than 80 80-160 160-240 240-320 320-400 400-480 480-560 560-640 640-720 720-800 800-1000 more than 1000 Diseases of the endocrine system are common,[14] including conditions such as diabetes mellitus, thyroid disease, and obesity. Endocrine disease is characterized by dysregulated hormone release (a productive pituitary adenoma), inappropriate response to signaling (hypothyroidism), lack of a gland (diabetes mellitus type 1, diminished erythropoiesis in chronic renal failure), or structural enlargement in a critical site such as the testis (toxic multinodular goitre). Hypofunction of endocrine glands can occur as a result of loss of reserve, hyposecretion, agenesis, atrophy, or active destruction. Hyperfunction can occur as a 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. Secondary endocrine disease is indicative of a problem with the pituitary gland. Tertiary endocrine disease is associated with dysfunction of the hypothalamus and its releasing hormones.[citation needed] As the thyroid, and hormones have been implicated in signaling distant tissues to proliferate, for example, the estrogen receptor has been shown to be involved in certain breast cancers. Endocrine, paracrine, and autocrine signaling have all been implicated in proliferation, one of the required steps of oncogenesis.[15] [edit] See also [edit] References - ^ University of Virginia - HISTOLOGY OF THE ENDOCRINE GLANDS
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- ^ Frühbeck G (July 2004). "The adipose tissue as a source of vasoactive factors". Curr Med Chem Cardiovasc Hematol Agents 2 (3): 197–208. doi:10.2174/1568016043356255. PMID 15320786. http://openurl.ingenta.com/content/nlm?genre=article&issn=1568-0169&volume=2&issue=3&spage=197&aulast=Frühbeck.
- ^ Colorado State University - Biomedical Hypertextbooks - Somatostatin
- ^ Endo K, Matsumoto T, Kobayashi T, Kasuya Y, Kamata K (February 2005). "Diabetes-related changes in contractile responses of stomach fundus to endothelin-1 in streptozotocin-induced diabetic rats" ([dead link] – Scholar search). J Smooth Muscle Res 41 (1): 35–47. doi:10.1540/jsmr.41.35. PMID 15855738. http://joi.jlc.jst.go.jp/JST.JSTAGE/jsmr/41.35?from=PubMed.
- ^ a b Physiology at MCG 5/5ch4/s5ch4_17
- ^ Pentikäinen V, Erkkilä K, Suomalainen L, Parvinen M, Dunkel L (May 2000). "Estradiol acts as a germ cell survival factor in the human testis in vitro". J Clin Endocrinol Metab. 85 (5): 2057–67. doi:10.1210/jc.85.5.2057. PMID 10843196. http://jcem.endojournals.org/cgi/pmidlookup?view=long&pmid=10843196.
- ^ a b c d Placental Hormones
- ^ Physiology at MCG 5/5ch9/s5ch9_13
- ^ Hould F, Fried G, Fazekas A, Tremblay S, Mersereau W (1988). "Progesterone receptors regulate gallbladder motility". J Surg Res 45 (6): 505–12. doi:10.1016/0022-4804(88)90137-0. PMID 3184927.
- ^ Hormonal Therapy
- ^ Massaro D, Massaro GD (2004). "Estrogen regulates pulmonary alveolar formation, loss, and regeneration in mice". American Journal of Physiology. Lung Cellular and Molecular Physiology 287 (6): L1154–9. doi:10.1152/ajplung.00228.2004. PMID 15298854.
- ^ "Mortality and Burden of Disease Estimates for WHO Member States in 2002" (xls). World Health Organization. 2002. http://www.who.int/entity/healthinfo/statistics/bodgbddeathdalyestimates.xls.
- ^ Kasper et al. (2005). Harrison's Principles of Internal Medicine. McGraw Hill. pp. 2074. ISBN 0-07-139140-1.
- ^ Bhowmick NA, Chytil A, Plieth D, et al. (February 2004). "TGF-beta signaling in fibroblasts modulates the oncogenic potential of adjacent epithelia". Science 303 (5659): 848–51. doi:10.1126/science.1090922. PMID 14764882.
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