Hipotàlem: diferència entre les revisions
Contingut suprimit Contingut afegit
Traduint |
#QQ16 |
||
| Línia 1: | Línia 1: | ||
{{Traduint|en|Hypothalamus}} |
|||
{{Infobox Brain |
{{Infobox Brain |
||
| Name = Hipotàlem |
| Name = Hipotàlem |
||
| Línia 41: | Línia 43: | ||
|- |
|- |
||
|rowspan=8|Anterior |
|rowspan=8|Anterior |
||
| Preoptic |
| Preoptic|| [[Preoptic area|Preoptic nucleus]] |
||
|- |
|- |
||
|rowspan=5|Medial |
|rowspan=5|Medial |
||
| Línia 110: | Línia 112: | ||
| [[Lateral hypothalamic nucleus|Lateral nucleus]] || See [[Lateral hypothalamus#Function]] – primary source of [[orexin]] neurons throughout the brain and spinal cord |
| [[Lateral hypothalamic nucleus|Lateral nucleus]] || See [[Lateral hypothalamus#Function]] – primary source of [[orexin]] neurons throughout the brain and spinal cord |
||
|- |
|- |
||
| [[Tuberomammillary nucleus]]<ref name="Histamine pathways">{{cite book |vauthors=Malenka RC, Nestler EJ, Hyman SE |veditors=Sydor A, Brown RY | title = Molecular Neuropharmacology: A Foundation for Clinical Neuroscience | year = 2009 | publisher = McGraw-Hill Medical | location = New York | isbn = 9780071481274 | pages = 175–176 | edition = 2nd | chapter = Chapter 6: Widely Projecting Systems: Monoamines, Acetylcholine, and Orexin | quote = Within the brain, histamine is synthesized exclusively by neurons with their cell bodies in the tuberomammillary nucleus (TMN) that lies within the posterior hypothalamus. There are approximately 64000 histaminergic neurons per side in humans. These cells project throughout the brain and spinal cord. Areas that receive especially dense projections include the cerebral cortex, hippocampus, neostriatum, nucleus accumbens, amygdala, and hypothalamus. ... While the best characterized function of the histamine system in the brain is regulation of sleep and arousal, histamine is also involved in learning and memory ... It also appears that histamine is involved in the regulation of feeding and energy balance.}}</ref |
| [[Tuberomammillary nucleus]]<ref name="Histamine pathways">{{cite book |vauthors=Malenka RC, Nestler EJ, Hyman SE |veditors=Sydor A, Brown RY | title = Molecular Neuropharmacology: A Foundation for Clinical Neuroscience | year = 2009 | publisher = McGraw-Hill Medical | location = New York | isbn = 9780071481274 | pages = 175–176 | edition = 2nd | chapter = Chapter 6: Widely Projecting Systems: Monoamines, Acetylcholine, and Orexin | quote = Within the brain, histamine is synthesized exclusively by neurons with their cell bodies in the tuberomammillary nucleus (TMN) that lies within the posterior hypothalamus. There are approximately 64000 histaminergic neurons per side in humans. These cells project throughout the brain and spinal cord. Areas that receive especially dense projections include the cerebral cortex, hippocampus, neostriatum, nucleus accumbens, amygdala, and hypothalamus. ... While the best characterized function of the histamine system in the brain is regulation of sleep and arousal, histamine is also involved in learning and memory ... It also appears that histamine is involved in the regulation of feeding and energy balance.}}</ref>|| |
||
* [[arousal]] (wakefulness and attention) |
* [[arousal]] (wakefulness and attention) |
||
* feeding and [[energy balance (biology)|energy balance]] |
* feeding and [[energy balance (biology)|energy balance]] |
||
| Línia 206: | Línia 208: | ||
|- |
|- |
||
! [[Oxytocin]] |
! [[Oxytocin]] |
||
| OXY or OXT || [[Magnocellular neurosecretory cell]]s of the paraventricular nucleus and [[supraoptic nucleus]] || [[Uterine contraction]] <br>[[Letdown reflex|Lactation (letdown reflex)]] |
| OXY or OXT || [[Magnocellular neurosecretory cell]]s of the paraventricular nucleus and [[supraoptic nucleus]] || [[Uterine contraction]] <br>[[Letdown reflex|Lactation (letdown reflex)]] |
||
|- |
|- |
||
! [[Vasopressin]] <br>(antidiuretic hormone) |
! [[Vasopressin]] <br>(antidiuretic hormone) |
||
| Línia 237: | Línia 239: | ||
It is not clear how all peptides that influence hypothalamic activity gain the necessary access. In the case of [[prolactin]] and [[leptin]], there is evidence of active uptake at the [[choroid plexus]] from the blood into the [[cerebrospinal fluid]] (CSF). Some pituitary hormones have a negative feedback influence upon hypothalamic secretion; for example, [[growth hormone]] feeds back on the hypothalamus, but how it enters the brain is not clear. There is also evidence for central actions of [[prolactin]].{{citation needed|date=February 2013}} |
It is not clear how all peptides that influence hypothalamic activity gain the necessary access. In the case of [[prolactin]] and [[leptin]], there is evidence of active uptake at the [[choroid plexus]] from the blood into the [[cerebrospinal fluid]] (CSF). Some pituitary hormones have a negative feedback influence upon hypothalamic secretion; for example, [[growth hormone]] feeds back on the hypothalamus, but how it enters the brain is not clear. There is also evidence for central actions of [[prolactin]].{{citation needed|date=February 2013}} |
||
Findings have suggested that [[thyroid hormone]] (T4) is taken up by the hypothalamic [[glial cells]] in the [[infundibular nucleus]]/ [[median eminence]], and that it is here converted into [[Triiodothyronine|T3]] by the type 2 deiodinase (D2). Subsequent to this, T3 is transported into the [[thyrotropin-releasing hormone]] ([[TRH]])-producing [[neurons]] in the [[paraventricular nucleus]]. [[Thyroid hormone receptor]]s have been found in these [[neurons]], indicating that they are indeed sensitive to T3 stimuli. In addition, these neurons expressed [[SLC16A2|MCT8]], a [[thyroid hormone]] transporter, supporting the theory that T3 is transported into them. T3 could then bind to the thyroid hormone receptor in these neurons and affect the production of thyrotropin-releasing hormone, thereby regulating thyroid hormone production.<ref>{{cite journal|last=Fliers|first=Eric|author2=Unmehopa, Alkemade|title=Functional neuroanatomy of thyroid hormone feedback in the human hypothalamus and pituitary gland|journal=Molecular and Cellular Endocrinology|date=7 June 2006|volume=251|issue=1–2|pages=1–8|doi=10.1016/j.mce.2006.03.042|pmid=16707210}} |
Findings have suggested that [[thyroid hormone]] (T4) is taken up by the hypothalamic [[glial cells]] in the [[infundibular nucleus]]/ [[median eminence]], and that it is here converted into [[Triiodothyronine|T3]] by the type 2 deiodinase (D2). Subsequent to this, T3 is transported into the [[thyrotropin-releasing hormone]] ([[TRH]])-producing [[neurons]] in the [[paraventricular nucleus]]. [[Thyroid hormone receptor]]s have been found in these [[neurons]], indicating that they are indeed sensitive to T3 stimuli. In addition, these neurons expressed [[SLC16A2|MCT8]], a [[thyroid hormone]] transporter, supporting the theory that T3 is transported into them. T3 could then bind to the thyroid hormone receptor in these neurons and affect the production of thyrotropin-releasing hormone, thereby regulating thyroid hormone production.<ref>{{cite journal|last=Fliers|first=Eric|author2=Unmehopa, Alkemade|title=Functional neuroanatomy of thyroid hormone feedback in the human hypothalamus and pituitary gland|journal=Molecular and Cellular Endocrinology|date=7 June 2006|volume=251|issue=1–2|pages=1–8|doi=10.1016/j.mce.2006.03.042|pmid=16707210}}</ref> |
||
The hypothalamus functions as a type of [[thermostat]] for the body.<ref name=Harrisons>{{cite book |
The hypothalamus functions as a type of [[thermostat]] for the body.<ref name=Harrisons>{{cite book |
||
Revisió del 19:21, 21 des 2016
 |
Aquest article o secció s'està traduint a partir de: «Hypothalamus» (anglès), amb llicència CC-BY-SA Hi pot haver llacunes de contingut, errors sintàctics o escrits sense traduir. |
L'hipotàlem (del grec ὑπό, sota, i θάλαμος, tàlem) és una porció del cervell que conté una petita quantitat de nuclis amb funcions ben diverses. Una de les més importats és enllaçar el sistema nerviós amb el sistema endocrí a través de la glàndula pituïtària (la hipòfisi).
Aquesta part del cervell es troba situada a sota del tàlem i forma part del sistema límbic.[1] En terminologia neuroanatòmica, forma la part ventral del diencèfal. Tots els vertebrats tenen hipotàlem. En humans és de la mida d'una ametlla.
L'hipotàlem és s'encarrega de dirigir certs processos biològics i altres funcions del sistema nerviós autònom. Sintetitza i secreta neurohormones anomenades hormones alliberadores o hormones de l'hipotàlem que estimulen o inhibeixen la secreció d'hormones per part de la glàndula pituïtària. L'hipotàlem controla la temperatura corporal, la gana, aspectes importants dels lligams familiars i maternals, la set,[2] la fatiga, el son i el ritme circadià.
Vegeu també
 |
A Wikimedia Commons hi ha contingut multimèdia relatiu a: Hipotàlem |
- ↑ Boeree, C. George. «The emotional nervous system». [Consulta: 21 desembre 2016].
- ↑ «Definition of the hypothalamus». NCI Dictionary of Cancer Terms. National Cancer Institute. [Consulta: 21 desembre 2016].