Hormone
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| + | A '''hormone''' (from [[Greek language|Greek]] ὁρμή, "[[impetus]]") is a [[chemical]] released by a [[cell]] or a [[gland]] in one part of the body that sends out messages that affect cells in other parts of the organism. Only a small amount of hormone is required to alter cell [[metabolism]]. In essence, it is a chemical messenger that transports a signal from one cell to another. All [[multicellular organism]]s produce hormones; [[plant]] hormones are also called [[phytohormone]]s. Hormones in [[animal]]s are often transported in the blood. Cells respond to a hormone when they [[gene expression|express]] a specific [[receptor (biochemistry)|receptor]] for that hormone. The hormone binds to the receptor [[protein]], resulting in the activation of a [[signal transduction]] mechanism that ultimately leads to cell type-specific responses. | ||
| - | '''Chemical castration''' is a form of [[castration]] caused by [[hormone|hormonal]] [[medication]] which reduces [[libido]]. It is used mainly by countries as a preventive measure or punishment on people who violate their laws on sexual behavior, for example those who have committed [[rape]] or [[child sexual abuse]] or who are [[homosexual]] (as in the case of mathematician [[Alan Turing]]. It has also been used by [[eugenics|eugenicists]] as a means of preventing people the government deems inferior from breeding, and was practiced in [[compulsory sterilization|many states]] during the twentieth century. | + | [[endocrine system|Endocrine]] hormone [[molecule]]s are secreted (released) directly into the [[bloodstream]], whereas [[exocrine gland|exocrine hormones]] (or ectohormones) are secreted directly into a duct, and, from the duct, they flow either into the bloodstream or from cell to cell by [[diffusion]] in a process known as [[paracrine signalling]]. |
| - | ==Historical use== | + | Recently it has been found that a variety of [[exogenous]] [[xenoestrogen|modern chemical compounds]] have hormone-like effects on both humans and wildlife. Their [[Endocrine disruptor|interference]] with the synthesis, secretion, transport, binding, action, or elimination of natural hormones in the body can change the [[homeostasis]], reproduction, development, and/or behavior, just as [[endogenous|endogenously]] produced hormones do. |
| - | During the [[Third Reich]], experimental procedures involving injection of chemicals, hormones and mutative radiation techniques, such as intentionally exposing individuals’ [[genitals]] to [[X-Ray]], were employed by the [[Nazis]] as a form of racial [[sterilisation]]. Individuals deemed ‘[[undesirable]]’ or ‘[[subhuman]]’/'[[untermensch]]' were subjected to such processes. [[Concentration camps]] including [[Auschwitz]] were places of abundant human specimen that the Nazis used to experiment different techniques in order to successfully and calculatedly sterilise suathes of the 'undesirables' in the wider German population. Examples of the drugs the nazis used on individuals are [[formalin]], [[novacain]], [[progynon]], and [[prolusion]]. [[Depo-Provera]], a [[progestin]], is a drug that is sometimes used on [[sex offenders]]. | + | |
| + | == Important human hormones == | ||
| + | ''See: [[List of human hormones]]'' | ||
| + | |||
| + | == See also == | ||
| + | <div style="-moz-column-count:3; column-count:3;"> | ||
| + | * [[Endocrinology]] | ||
| + | * [[Endocrine system]] | ||
| + | * [[Neuroendocrinology]] | ||
| + | * [[Plant hormones]] or [[plant growth regulators]] | ||
| + | * [[Autocrine signaling]] | ||
| + | * [[Paracrine signaling]] | ||
| + | * [[Intracrine]] | ||
| + | * [[Cytokine]] | ||
| + | * [[Growth factor]] | ||
| + | * [[Hormone disruptor]] | ||
| + | * [[Sexual motivation and hormones]] | ||
| + | </div> | ||
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A hormone (from Greek ὁρμή, "impetus") is a chemical released by a cell or a gland in one part of the body that sends out messages that affect cells in other parts of the organism. Only a small amount of hormone is required to alter cell metabolism. In essence, it is a chemical messenger that transports a signal from one cell to another. All multicellular organisms produce hormones; plant hormones are also called phytohormones. Hormones in animals are often transported in the blood. Cells respond to a hormone when they express a specific receptor for that hormone. The hormone binds to the receptor protein, resulting in the activation of a signal transduction mechanism that ultimately leads to cell type-specific responses.
Endocrine hormone molecules are secreted (released) directly into the bloodstream, whereas exocrine hormones (or ectohormones) are secreted directly into a duct, and, from the duct, they flow either into the bloodstream or from cell to cell by diffusion in a process known as paracrine signalling.
Recently it has been found that a variety of exogenous modern chemical compounds have hormone-like effects on both humans and wildlife. Their interference with the synthesis, secretion, transport, binding, action, or elimination of natural hormones in the body can change the homeostasis, reproduction, development, and/or behavior, just as endogenously produced hormones do.
Important human hormones
See also
