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The hypothalamus (from Greek ὑπό, "under" and θάλαμος, "room, chamber") is a portion of the brain that contains a number of small nuclei with a variety of functions. One of the most important functions of the hypothalamus is to link the nervous system to the endocrine system via the pituitary gland (hypophysis). The hypothalamus is located below the thalamus, just above the brainstem and is part of the limbic system.〔Limbic system〕 In the terminology of neuroanatomy, it forms the ventral part of the diencephalon. All vertebrate brains contain a hypothalamus. In humans, it is the size of an almond. The hypothalamus is responsible for certain metabolic processes and other activities of the autonomic nervous system. It synthesizes and secretes certain neurohormones, often called releasing hormones or hypothalamic hormones, and these in turn stimulate or inhibit the secretion of pituitary hormones. The hypothalamus controls body temperature, hunger, important aspects of parenting and attachment behaviors, thirst,〔(Definition of hypothalamus - NCI Dictionary of Cancer Terms )〕 fatigue, sleep, and circadian rhythms. ==Structure== The hypothalamus is a brain structure made up of distinct nuclei as well as less anatomically distinct areas. It is found in all vertebrate nervous systems. In mammals, magnocellular neurosecretory cells in the paraventricular nucleus and the supraoptic nucleus of the hypothalamus produce oxytocin and vasopressin. These hormones are released into the blood in the posterior pituitary. Much smaller parvocellular neurosecretory cells, neurons of the paraventricular nucleus, release corticotropin-releasing hormone and other hormones into the hypophyseal portal system, where these hormones diffuse to the anterior pituitary. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「hypothalamus」の詳細全文を読む スポンサード リンク
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