Communication with the hypothalamus pituitary
Endocrinology / / May 23, 2016
hypothalamus - a brain region bounded by the optic chiasm, optic tract, the inner edge of the brain legs, perforated rear space.On top of the hypothalamus is separated from the thalamus hypothalamic sulcus.The caudal border of the hypothalamus - a plane passing behind the papillary bodies red knoll (subst nigra.).The hypothalamus is located 32 pairs of nuclei, which can be divided into five groups - preoptic, anterior, middle, and outer rear group.The hypothalamus is closely nervous due to a number of other parts of the central nervous system - the cerebral cortex, the reticular formation.
Wealth neural connections of the hypothalamus with various departments of the central nervous system, especially vascularization - the abundance of capillaries, the high permeability of the vascular wall to large protein molecules, the final nature of the arteries that provide isolated the blood supply to different groups of nuclei, as well as the proximity of the hypothalamic nuclei to likvoroprovodyaschim paths c
nuclei of the hypothalamus involved in regulating major autonomic functions of the body.The hypothalamus is located higher centers of the sympathetic and parasympathetic autonomic nervous system centers that regulate heat production and heat loss, blood pressure, appetite (and therefore weight), vascular permeability, a number of metabolic processes.hypothalamic centers to be more involved in the regulation of sleep and wakefulness, as well as have an impact on mental activity, particularly in the emotional sphere.
has now been found that the hypothalamus has a regulating effect on the hormones of the anterior pituitary.Even in 1912 Aschner watched genital atrophy in dogs after hypothalamic lesions.In the future, the facts speak about the participation of the hypothalamus were obtained in the regulation of ovarian ovulatory function of changes in the thyroid gland after hypothalamic lesions.However, the mechanism of the hypothalamus influence on the activity of the adenohypophysis remained unclear.
was found that the relationship with the hypothalamus anterior pituitary carried humoral way through the portal system.
Branch of the hypothalamus pituitary and transplant it to the parts of the body distant from the hypothalamus, causing cessation of the production of follicle-stimulating and possibly luteinizing hormone, a significant decrease in the production of adrenocorticotropic hormone and thyroid-stimulating.Prolactin in violation of the vascular pituitary connection with the hypothalamus increases.This supports the idea that the hypothalamus has an inhibitory effect on the production of prolactin.Spiking hypophysectomized animals the pituitary gland in the base of the brain results in regeneration after portal system to restore hormonal pituitary function.
greatest amount of information is available about the role of the hypothalamus in the regulation of ACTH secretion.The centers of the hypothalamus, apparently mainly regulate ACTH selection under stress.The basal secretion of ACTH anterior pituitary depends little on the hypothalamic influences and maintained after transection of the pituitary stalk or transfer it to the field, distant from the hypothalamus.Studies with isolated disruption or irritation of certain nuclei of the hypothalamus was shown that the greatest importance in the regulation of ACTH production are the nucleus of the posterior hypothalamus, tuber cinereum and eminentia medialis.He ruled out the possibility that, along with the centers, stimulating the production of ACTH in the hypothalamus are centers which inhibit the production of this hormone.ACTH - the first of the anterior pituitary hormones, in respect of which it is shown that the hypothalamus regulates its production of humoral way.There are a number of experimental studies showing that ACTH stimulates the production of vasopressin may have.However, damage to the anterior hypothalamus, which produces vasopressin, does not affect the production of ACTH.Patients with diabetes insipidus have no signs of decrease in adrenocortical function and react normally to stress.A number of factors that increase the ACTH product, inhibits the production of vasopressin.All this suggests that under physiological conditions, in physiological doses has no effect on vasopressin, ACTH production.
number of researchers from the hypothalamus extracts were obtained fractions having a high ability to stimulate the production of anterior pituitary ACTH.This is - substances of polypeptide nature.One faction, which has lower activity, similar in structure to the melanocyte stimulating hormone;the other - a more active - is similar in chemical structure to vasopressin.
studies with isolated lesion and stimulation of hypothalamic nuclei allowed to establish the localization of the hypothalamic centers that regulate the production of thyroid-stimulating hormone and gonadotropin.It is also shown that the hypothalamus regulates the impact on the production of these hormones is carried out by humoral.
obtained data indicating that the anterior pituitary secretion of growth hormone is also regulated by the hypothalamus.It is established that causes damage in rat hypothalamic growth delay and reduces the content of growth hormone in the pituitary.hypothalamic extracts stimulate the secretion of pituitary growth hormone in vitro and in vivo.Hypothalamic factors stimulating the secretion of growth hormone, prepared in purified form, and it is installed polypeptide nature.
- deficiency of the anterior pituitary
- deficiency of the anterior pituitary.The clinical picture
- deficiency of the anterior pituitary.These hormonal studies
- deficiency of the anterior pituitary.The disease
- deficiency of the anterior pituitary.Diagnosis and differential diagnosis
- Treatment failure of the anterior pituitary
In assessing the role of the hypothalamus in the regulation of production anterior pituitary hormones is necessary to consider that the hypothalamus is the one area of the brain, which summarizesimpulses coming from different parts of the central nervous system - the cerebral cortex, subcortical nuclei (nucl amygdalar..), the reticular formation.The hypothalamus is a transformation of nerve impulses in the humoral.
first data on the impact of the activity of the hypothalamus in the neurohypophysis were obtained in 1920, when Camus and Roussy observed the development of diabetes insipidus in the animal after hypothalamic lesions.It was subsequently found that electrical stimulation of the hypothalamus causes inhibition of diuresis and neurohypophyseal hormones that are found in the hypothalamus.
In 1951, Bargmann and Scharrer formulated an idea that neurohypophyseal hormones produced in the preoptic and paraventricular nuclei of the hypothalamus and from there along the axons of nerve cells act in the neurohypophysis.For the same nerve fibers in the neurohypophysis receives sekretomotornym impulses stimulate the secretion of hormones in the blood.
09 May, 2016
09 May, 2016