The hypothalamus acts as an endocrine organ as it synthesizes hormones and transports them along axons to the posterior pituitary gland. The hypothalamus also synthesizes and secretes regulatory hormones (statins and liberins) that control the endocrine cells in the anterior pituitary gland. In addition, it contains autonomic centers that control endocrine cells in the adrenal medulla via neuronal control. The hypothalamus is highly interconnected with other parts of the central nervous system, in particular the brainstem and its reticular formation. As part of the limbic system, it has connections to other limbic structures including the amygdala and septum, and is also connected with areas of the autonomous nervous system.
The hypothalamus coordinates many hormonal and behavioral circadian rhythms, complex patterns of neuroendocrine outputs, complex homeostatic mechanisms, and important behaviors. The hypothalamus must, therefore, respond to many different signals, some of which generated externally and some internally. Delta wave signaling arising either in the thalamus or in the cortex influences the secretion of releasing hormones; GHRH (growth hormone–releasing hormone) and prolactin are stimulated whilst TRH (thyrotropin-releasing hormone) is inhibited.
The hypothalamus is responsive to:
Via the pituitary gland it controls the following body processes:
The absence of a menstrual period in women of reproductive age.
An eating disorder characterized by the maintenance of a body weight below average, fear of gaining weight, and a distorted body image.
Failure of the ovaries to release an oocyte over a period of time generally exceeding 3 months.
Complete absence of sperm in the ejaculate of a man.
The inability (that lasts more than 6 months) to develop or maintain an erection of the penis during sexual activity.
The presence of abnormally high levels of prolactin in the blood.
A medical term which describes a diminished functional activity of the gonads – the testes and ovaries.
Partial or complete loss of production of one or more of the pituitary gland hormones.
A genetic condition where the primary symptom is a failure to start puberty or a failure to fully complete puberty.
The set of symptoms that result from two or more X chromosome in males.
The time in most women's lives when menstrual periods stop permanently, and the woman is no longer able to have children.
An abnormal condition in a woman's menstrual cycle.
Complete absence of sperm in the ejaculate due to testicular failure.
Semen with a low concentration of sperm and is a common finding in male infertility.
The inability of the testicles to produce sperm or testosterone.
A medical condition impairing the function of the thyroid.
In the case of cryptorchidism one or both testes are absent from the scrotum. It is is the most common etiologic factor of azoospermy in the adult.
A releasing hormone responsible for the release of follicle-stimulating hormone (FSH) and luteinizing hormone (LH) from the anterior pituitary.
An anovulatory cycle is a menstrual cycle during which the ovaries do not release an oocyte.
The failure to achieve a clinical pregnancy after 12 months or more of regular unprotected sexual intercourse.
Irregular menstruation is a menstrual disorder whose manifestations include irregular cycle lengths as well as metrorrhagia
The age at onset of first menstruation.