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Hunger

2007 Schools Wikipedia Selection. Related subjects: Health and medicine

   Hunger is a feeling experienced by animals when the glycogen level of
   the liver falls below a certain point, usually followed by a desire to
   eat. The usually unpleasant feeling originates in the hypothalamus and
   is released through receptors in the liver and stomach. An average
   nourished human can survive about 50 days without food intake. Hunger
   can also be applied metaphorically to cravings of other sorts.

   The term is commonly used more broadly to refer to cases of widespread
   malnutrition or deprivation among populations, usually due to poverty,
   political conflicts or instability, or adverse agricultural conditions
   (famine). (See malnutrition for statistics and other information on
   hunger as a political and economic problem.)

Number of People Living in Hunger

   According to The Borgen Project over 800 million people across the
   globe live in hunger. The condition is preventable and in September of
   2000, the largest gathering of world leaders ever assembled met at a
   summit in New York City and agreed to a plan to end it by 2015. Known
   as the U.N. Millennium Goals, the plan to end world hunger has been
   agreed to by every nation on earth.

   ==Physiology==f

   Hunger is mediated by several molecular signalling pathways in mammals.
   Hormones known to affect hunger include ghrelin, leptin, and Peptide
   YY3-36 .

Satiety

   Painting by Carl von Bergen (1904).
   Enlarge
   Painting by Carl von Bergen (1904).

   Satiety, or the feeling of fullness and disappearance of appetite after
   a meal, is a process mediated by the ventromedial nucleus in the
   hypothalamus. It is therefore the "satiety centre".

   Various hormones, first of all cholecystokinin, have been implicated in
   conveying the feeling of satiety to the brain. Leptin increases on
   satiety, while ghrelin increases when the stomach is empty.

   Therefore, satiety refers to the psychological feeling of "fullness" or
   satisfaction rather than to the physical feeling of being engorged,
   i.e. the feeling of physical fullness after eating a very large meal.

   Satiety directly influences feelings of appetite that are generated in
   the limbic system, and hunger that is controlled by neurohormones,
   especially serotonin in the lateral hypothalamus.

Links

     * The Borgen Project
     * The ONE Campaign
     * World Hunger Map
     * Local United Network to Combat Hunger

   Retrieved from " http://en.wikipedia.org/wiki/Hunger"
   This reference article is mainly selected from the English Wikipedia
   with only minor checks and changes (see www.wikipedia.org for details
   of authors and sources) and is available under the GNU Free
   Documentation License. See also our Disclaimer.
