n. a hormone that is produced within specialized nerve cells and is secreted from the nerve endings into the circulation. Examples are the hormones oxytocin and vasopressin, produced within the nerve cells of the hypothalamus and released into the circulation in the posterior pituitary gland, and noradrenaline, released from *chromaffin tissue in the adrenal medulla.
An endocrine gland somewhat behind the eyes and suspended from the front of the brain. The front section, the anterior pituitary, makes and secretes a number of controlling hormones that affect the rate of oxidation; the preference for fats, sugars, or proteins for fuel; the rate of growth and repair in the bones, connective tissue, muscles, and skin; the ebb and flow of steroid hormones from both the gonads and adrenal cortices. It does this through both negative and positive feedback. The hypothalamus controls these functions, secreting its own hormones into a little portal system that feeds into the pituitary, telling the latter what and how much to do. The hypothalamus itself synthesizes the nerve hormones that are stored in the posterior pituitary, which is responsible for squirting them into the blood when the brain directs it to. These neurohormones act quickly, like adrenalin, to constrict blood vessels, limit diuresis in the kidneys, and trigger the complex responses of sexual excitation, milk letdown in nursing, and muscle stimulus in the uterus (birthing, orgasm, and menstrual contractions), prostate, and nipples.... pituitary
the system of dual control of certain activities of the body by means of both nerves and circulating hormones. The functioning of the autonomic nervous system is particularly closely linked to that of the pituitary and adrenal glands. The system can give rise to neuroendocrine tumours (NETs), which have special structural features and often produce active hormones. See also neurohormone; neurosecretion.... neuroendocrine system
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