hypothalamus


hypothalamus
hypothalamic /huy'poh theuh lam"ik, hip'oh-/, adj.
/huy'peuh thal"euh meuhs/, n., pl. hypothalami /-muy'/. Anat.
a region of the brain, between the thalamus and the midbrain, that functions as the main control center for the autonomic nervous system by regulating sleep cycles, body temperature, appetite, etc., and that acts as an endocrine gland by producing hormones, including the releasing factors that control the hormonal secretions of the pituitary gland.
[1895-1900; < NL; see HYPO-, THALAMUS]

* * *

Region of the brain containing a control centre for many autonomic-nervous-system functions.

Its complex interaction with the pituitary gland makes it an important part of the endocrine system. As a critical link between the body's two control systems, the hypothalamus regulates homeostasis. Nervous and hormonal pathways connect it with the pituitary, which it stimulates to release various hormones. The hypothalamus influences food intake, weight regulation, fluid intake and balance, thirst, body heat, and the sleep cycle. Disorders can produce pituitary dysfunction, diabetes insipidus, insomnia, and temperature fluctuations.

* * *

      region of the brain lying below the thalamus and making up the floor of the third cerebral ventricle. The hypothalamus contains a control centre for many functions of the autonomic nervous system, and it has effects on the endocrine system because of its complex interaction with the pituitary gland, which lies beneath it.

      The hypothalamus and pituitary gland are connected by both nervous and chemical pathways. Nerve tracts from the hypothalamus stimulate the release of oxytocin and vasopressin from the posterior pituitary gland; these hormones cause smooth-muscle contractions in the circulatory and reproductive systems. Hormones secreted from the hypothalamus trigger the release from the anterior pituitary of growth hormone, adrenocorticotropic hormone, luteinizing hormone, and other pituitary secretions.

      The hypothalamus influences caloric intake and weight regulation, establishing a stable “set point” for individual weight gain. The hypothalamus also regulates body heat in response to variations in external temperature, determines wakefulness and sleep, and regulates fluid intake and sensation of thirst.

      Injuries or diseases affecting the hypothalamus may produce symptoms of pituitary dysfunction or diabetes insipidus; in the latter disorder, the absence of antidiuretic hormone (a hormone that promotes the reabsorption of water in the kidneys) produced by the hypothalamus induces the rapid loss of water from the body through frequent urination. Hypothalamic disease can also cause insomnia and fluctuations in body temperature.

* * *


Universalium. 2010.

Look at other dictionaries:

  • HYPOTHALAMUS — Malgré ses dimensions restreintes (quelques centimètres cubes chez l’homme), l’hypothalamus s’est peu à peu révélé comme le centre majeur des régulations homéostasiques. En tant que tel, il jouera donc un rôle fondamental dans tous les grands… …   Encyclopédie Universelle

  • Hypothalamus. — Hypothalamus.   Der Hypothalamus liegt unter dem Thalamus, beide zusammen bilden das Zwischenhirn (Diencephalon), das seinerseits zwischen dem Groß oder Endhirn (Telencephalon) und dem Mittelhirn (Mesencephalon) liegt und in beiden Richtungen mit …   Universal-Lexikon

  • Hypothalamus — Hypothalamus, ventraler Teil des Zwischenhirns der Wirbeltiere, Koordinationszentrum des vegetativen Nervensystems, Schaltstelle zwischen diesem, Teilen des ZNS und dem Hormonsystem mit folgenden Funktionsbereichen: 1) Homöostatische Funktionen:… …   Deutsch wörterbuch der biologie

  • hypothalamus — 1896, coined 1893 in German from Gk. hypo under (see SUB (Cf. sub )) + thalamus part of the brain where a nerve emerges …   Etymology dictionary

  • HYPOTHALAMUS — HYPOTHALAMUS, одна из частей промежуточного мозга (diencephalon), лежащая книзу от thalamus opticus,nofl fissura Monroi, к рая тянется от foramen Monroi к aquae ductus Sylvii; H. образует нижнюю стенку III желудочка; подразделяется на pars optica …   Большая медицинская энциклопедия

  • hypothalamus — [hī΄pō thal′ə məs] n. pl. hypothalami [hī pō thal′əmī΄] [ModL: see HYPO & THALAMUS] the part of the diencephalon in the brain that forms the floor of the third ventricle and regulates many basic body functions, as temperature hypothalamic… …   English World dictionary

  • Hypothalamus — Brain: Hypothalamus Location of the human hypothalamus …   Wikipedia

  • Hypothalamus — Traduction en cours Cette page est en cours de traduction (en français) à partir de l article Hypothalamus (3 juin 2011 Gretaz). Si vous souhaitez participer à la traduction, il vous suffit d éditer cette page. Merci de corriger les erreurs… …   Wikipédia en Français

  • Hypothalamus — Lage des Hypothalamus Der Hypothalamus (griech. ὑπό = unter und θάλαμος = Zimmer, Kammer) ist ein Abschnitt des Zwischenhirns im Bereich der Sehnervenkreuzung (Chiasma opticum). Medial wird der Hypothalamus vom dritten Ventrikel, kranial vom… …   Deutsch Wikipedia

  • Hypothalamus — Hy|po|thạ|la|mus 〈m.; , la|mi; Anat.〉 unter dem Thalamus liegender Teil des Zwischenhirns [<grch. hypo „unter“ + Thalamus] * * * Hy|po|tha|la|mus, der; [zu ↑ Thalamus] (Anat.): unterhalb des Thalamus liegender Teil des Zwischenhirns. * * * I …   Universal-Lexikon


Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”

We are using cookies for the best presentation of our site. Continuing to use this site, you agree with this.