hypothalamus

A primary function of the hypothalamus is regulation of the autonomic nervous system. The hypothalamus integrates autonomic response and endocrine function with behavior to maintain homeostasis of certain systems. Blood pressure and electrolyte composition are maintained by control of drinking and salt appetite. Body temperature is regulated by control of metabolic thermogenesis and behaviors that seek to warm or cool the individual. Energy metabolism is regulated by feeding, digestion, and metabolic rate. Reproduction is regulated through hormonal control. Emergency responses to stress are controlled by regulating blood flow to muscle and other tissues, and by the release of adrenal stress hormones. The hypothalamus receives inputs of sensory information from all over the body, compares this information with biologic set points and, upon detection of deviation from the set points, adjusts autonomic, endocrine, and behavioral responses to return to homeostasis. Hypothalamic influence is exerted directly upon the pituitary.


 *  **Region** ||  **Area**  ||  **Nucleus**  ||  **Function**  ||
 *  Anterior ||  Medial  ||  Medial preoptic nucleus  || *  Regulates the release of gonadotropic hormones from the adenohypophysis. Contains the sexually dimorphic nucleus, which releases GnRH.   ||
 * ^  ||^   ||  Supraoptic nucleus  || *  Oxytocin release, Vasopressin release   ||
 * ^  ||^   ||  Paraventricular nucleus  || *  Corticotropin-releasing hormone   ||
 * ^  ||^   ||  Anterior hypothalamic nucleus  || *  Thermoregulation, panting, sweating, thyrotropin inhibition   ||
 * ^  ||^   ||  Suprachiasmic nucleus  || *  Vasopressin release, circadian rhythms   ||
 * ^  || <span style="font-family: Times New Roman,serif;"> Lateral  || <span style="font-family: Times New Roman,serif;"> Lateral preoptic nucleus  ||   ||
 * ^  ||^   || <span style="font-family: Times New Roman,serif;"> Lateral Nucleua  || * <span style="font-family: Times New Roman,serif;"> Thirst and hunger   ||
 * ^  ||^   || <span style="font-family: Times New Roman,serif;"> Part of supraoptic nucleus  || * <span style="font-family: Times New Roman,serif;"> Vasopressin release   ||
 * <span style="font-family: Times New Roman,serif;"> Tuberal || <span style="font-family: Times New Roman,serif;"> Medial  || <span style="font-family: Times New Roman,serif;"> Dorsomedial hypothalamic nucleus  || <span style="font-family: Times New Roman,serif;"> Blood pressure, heart rate, GI stimulation  ||
 * ^  ||^   || <span style="font-family: Times New Roman,serif;"> Ventromedial nucleus  || <span style="font-family: Times New Roman,serif;"> Satiety, neuroendocrine control  ||
 * ^  ||^   || <span style="font-family: Times New Roman,serif;"> Arcuate nucleus  || <span style="font-family: Times New Roman,serif;"> Growth hormone releleasing hormone (GHRH), feeding, dopamine  ||
 * ^  || <span style="font-family: Times New Roman,serif;"> Lateral  || <span style="font-family: Times New Roman,serif;"> Lateral nucleus  || <span style="font-family: Times New Roman,serif;"> Thirst, hunger  ||
 * ^  ||^   || <span style="font-family: Times New Roman,serif;"> Lateral tuberal nuclei  ||   ||
 * <span style="font-family: Times New Roman,serif;"> Posterior || <span style="font-family: Times New Roman,serif;"> Medial  || <span style="font-family: Times New Roman,serif;"> Mammillary nuclei  || <span style="font-family: Times New Roman,serif;"> Memory  ||
 * ^  ||^   || <span style="font-family: Times New Roman,serif;"> Posterior nucleus  || <span style="font-family: Times New Roman,serif;"> Increased blood pressure, pupillary dilation, shivering  ||
 * ^  || <span style="font-family: Times New Roman,serif;"> Lateral  || <span style="font-family: Times New Roman,serif;"> Lateral nucleus  ||   ||


 * ~ <span style="font-family: Times New Roman,serif;"> Hormone  || <span style="font-family: Times New Roman,serif;"> **Produced by**   || <span style="font-family: Times New Roman,serif;"> **Effect**   ||
 * <span style="font-family: Times New Roman,serif;"> Thyrotropin-releasing hormone (TRH) || <span style="font-family: Times New Roman,serif;"> Parvocellular neurosecretory neurons   || <span style="font-family: Times New Roman,serif;"> -Stimulates t   [|hyroid-stimulating hormone (TSH)] <span style="font-family: Times New Roman,serif;"> release from   [|anterior pituitary]

<span style="font-family: Times New Roman,serif;"> -Stimulate  [|prolactin] <span style="font-family: Times New Roman,serif;"> release from   [|anterior pituitary] ||
 * <span style="font-family: Times New Roman,serif;"> Dopamine (DA) || <span style="font-family: Times New Roman,serif;"> Dopamine neurons of the arcuate nucleus   || <span style="font-family: Times New Roman,serif;"> -  <span style="font-family: Times New Roman,serif;"> Inhibits   [|prolactin] <span style="font-family: Times New Roman,serif;"> release from   [|anterior pituitary] ||
 * <span style="font-family: Times New Roman,serif;"> Growth hormone-releasing hormone (GRHR) || <span style="font-family: Times New Roman,serif;"> neurons of the Arcuate nucleus   || <span style="font-family: Times New Roman,serif;"> Stimulates   [|Growth hormone (GH)] <span style="font-family: Times New Roman,serif;"> release from   [|anterior pituitary] ||
 * <span style="font-family: Times New Roman,serif;"> Somatostatin (SS) || <span style="font-family: Times New Roman,serif;"> Neuroendocrine cells of the Periventricular nucleus   || <span style="font-family: Times New Roman,serif;"> Inhibits   [|Growth hormone (GH)] <span style="font-family: Times New Roman,serif;"> release from   [|anterior pituitary]

<span style="font-family: Times New Roman,serif;"> Inhibits  [|thyroid-stimulating hormone (TSH)] <span style="font-family: Times New Roman,serif;"> release from   [|anterior pituitary] ||
 * <span style="font-family: Times New Roman,serif;"> Gonadotrophin – releasing hormone (GnRH) || <span style="font-family: Times New Roman,serif;"> Neuroendocrine cells of the Preoptic area   || <span style="font-family: Times New Roman,serif;"> -Stimulates   [|follicle-stimulating hormone (FSH)] <span style="font-family: Times New Roman,serif;"> release from   [|anterior pituitary]

<span style="font-family: Times New Roman,serif;"> -Stimulate  [|luteinizing hormone (LH)] <span style="font-family: Times New Roman,serif;"> release from   [|anterior pituitary] ||
 * <span style="font-family: Times New Roman,serif;"> Corticotropin-releasing hormone (CRH) || <span style="font-family: Times New Roman,serif;"> Parvocellular neurosecretory neurons   || <span style="font-family: Times New Roman,serif;"> -Stimulate   [|adrenocorticotropic hormone (ACTH)] <span style="font-family: Times New Roman,serif;"> release from   [|anterior pituitary] ||
 * <span style="font-family: Times New Roman,serif;"> Oxytocin || <span style="font-family: Times New Roman,serif;"> Magnocellular neurosecretory cells   || <span style="font-family: Times New Roman,serif;"> -Uterine contraction

<span style="font-family: Times New Roman,serif;"> -  [|Lactation (letdown reflex)] ||
 * <span style="font-family: Times New Roman,serif;"> Vasopressin/antidiuretic hormone (ADH) || <span style="font-family: Times New Roman,serif;"> Magnocellular neurosecretory neurons   || <span style="font-family: Times New Roman,serif;"> Increase in the permeability to water of the cells of   [|distal tubule] <span style="font-family: Times New Roman,serif;"> and   [|collecting duct] <span style="font-family: Times New Roman,serif;"> in the kidney and thus allows water reabsorption and excretion of concentrated urine   ||


 * <span style="font-family: Times New Roman,serif;"> Lateral vs Medial Hypothalamic Lesion Effects  ||
 * <span style="font-family: Times New Roman,serif;"> Lateral Lesion || <span style="font-family: Times New Roman,serif;"> -Aphagia, adipsia (no motivation to eat or drink)

<span style="font-family: Times New Roman,serif;"> -Attenuated sense of pleasure and emotional responsiveness

<span style="font-family: Times New Roman,serif;"> -P athological laughter and crying

<span style="font-family: Times New Roman,serif;"> -Passiveness, inability to become aggressive   ||
 * <span style="font-family: Times New Roman,serif;"> Medial Lesion || <span style="font-family: Times New Roman,serif;"> -Hyperphagia, severe obesity (especially ventromedial)

<span style="font-family: Times New Roman,serif;"> -P athological laughter and crying

<span style="font-family: Times New Roman,serif;"> -Aggressive or attack behavior, rage-like outbursts, propensity toward violence   ||