Diferència entre revisions de la pàgina «Hipotàlem»

150 octets eliminats ,  fa 3 anys
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{{Traduint|en|Hypothalamus}}
 
{{Infobox Brain
| Name = Hipotàlem
|-
|rowspan=8|Anterior
| Preoptic<!--Per neurolex--> || [[Preoptic area|Preoptic nucleus]]
|-
|rowspan=5|Medial
| [[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. &nbsp;... 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&nbsp;... It also appears that histamine is involved in the regulation of feeding and energy balance.}}</ref> <!--Per neurolex and ref for this entry-->||
* [[arousal]] (wakefulness and attention)
* feeding and [[energy balance (biology)|energy balance]]
|-
! [[Oxytocin]]
| OXY or OXT || [[Magnocellular neurosecretory cell]]s of the paraventricular nucleus and [[supraoptic nucleus]] || [[Uterine contraction]] <br>[[Letdown reflex|Lactation (letdown reflex)]] <!--Not effects from hypothalamus: sexual arousal, bonding, trust, material behavior-->
|-
! [[Vasopressin]] <br>(antidiuretic hormone)
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}}<!--|accessdate=7 July 2011--></ref>
 
The hypothalamus functions as a type of [[thermostat]] for the body.<ref name=Harrisons>{{cite book